AWD or RWD? (split from new member question)

[Helo58]

F1 Teams? That's irrelevant to this discussion. We aren't -driving- F1 cars, nor are we discussing them. We're talking about a GT 4-door sedan. We also aren't 'fleet' operators - at least, I'm not. Another irrelevant analogy.

For the record, I pointed out, using your referenced test mind you, that what you called negligible was actually 5%. To most 5% matters. Personally, I get 5% cash back on my gas credit card, received a 5% bonus for writing a successful funding proposal at my job, and drove my RWD Stinger 5% further on a tank of gas that you did.

Keep moving the goal post, I have a good leg. (Let me guess, you don't like my analogy.)

 

[Kamauxx]

Is anyone here claiming the AWD Stinger is faster on the track? I don't recall anyone saying that.

For a second I thought I replied to the wrong thread. I went back and checked. On every page of this thread someone has indeed made that assertion.

There's also a reoccurring false equivalency being posted, essentially suggesting that because a $100k++ GTR, Porsche, Lamborghini, etc. uses AWD for track performance then Kia's AWD must be doing so as well. Some posters seem to believe that the AWD in a $40k Kia is set up the same as the AWD of supercars.

Kia's AWD should be being compared to Ford's not Buggati's.

 

[TimS]

Keep moving the goal post, I have a good leg. (Let me guess, you don't like my analogy.)

...and you keep on with the erroneous and ignorant analogies, and I'll keep kickin' them right back to you.

-Tim

 

[Helo58]

...and you keep on with the erroneous and ignorant analogies, and I'll keep kickin' them right back to you.

-Tim

Was the 5% worse gas mileage erroneous and ignorant or was it the 5% worse gas mileage?

 

[TimS]

Was the 5% worse gas mileage erroneous and ignorant or was it the 5% worse gas mileage?

After Lebron, Golden Eggs, F1 racing, Fleet management, and now goal posts - I think you've surpassed your quota of silly analogies for today.

But hey - it's a free forum - tally up some more if you feel froggy.

-Tim

 

[westcoastGT]

.........................Pass the popcorn.....................

 

[Helo58]

After Lebron, Golden Eggs, F1 racing, Fleet management, and now goal posts - I think you've surpassed your quota of silly analogies for today.

But hey - it's a free forum - tally up some more if you feel froggy.

-Tim

Well, you have taken my very basic premise made very early on that AWD gets worse gas mileage than RWD and deflected from it. As a result, I used analogies because you were too doltish and puerile to understand it directly. You failed to acknowledge simple scientific fact that is completely and readily accepted in the engineering and automotive world. It is so widely accepted that it is not even in question with anyone but you apparently. Literally no one questions this but you. Take a moment and reflect on that.

My point was made specifically in response to the OP's question regarding the choice between RWD and AWD. The facts I presented were from your referenced C&D test data, not my analogies. The OP can use the data as they see fit to answer their question(s). They showed that AWD gets 5% worse gas mileage. It has nothing to do with your 3000 miles per year or your annual fuel costs. Nobody cares that the financial difference is inconsequential to you. The point was simply that the mileage was worse. Your specific ramifications resulting from that are irrelevant. Why you deflected to that is deflection at its finest.

It isn't about me feeling froggy or tallying up anything. It was about presenting truth. Not my truth or your truth, but THE truth. There are more frictional losses in a more complex drivetrain. The car is heavier. Both contribute to poorer fuel economy. It really is that simple. I challenge you to find one accepted example of where a comparable (i.e. not hybrid, etc.) AWD drive version of a car gets greater gas mileage than the RWD. If you do, please present it to the forum and I'll be the first to admit I am wrong. Until then, keep the baseless smug and snarky comments to yourself. It isn't productive.

Admins/mods... don't worry. I'm done.

 

[jmf_tracy]

Stinger isn't a high end sports car though. Kia tuned their AWD systems for safety in the mountains of Colorado not for speed in the corners of the Nurburgring. You're fooling yourself if you think Kia's AWD systems are comparable to those of $150k track monsters.

Kia's AWD Stinger is not faster in a drag race or circuit course. That's an indisputable fact with videos and articles to back it up. Let no AWD Stinger owner tell you different (without proof).

Can AWD Stingers maybe possibly one day be tuned to be faster than RWD Stingers if enough money is thrown at em? Of course. But we are talking about today's stock cars not next year's highly modified cars.

For a second I thought I replied to the wrong thread. I went back and checked. On every page of this thread someone has indeed made that assertion.

There's also a reoccurring false equivalency being posted, essentially suggesting that because a $100k++ GTR, Porsche, Lamborghini, etc. uses AWD for track performance then Kia's AWD must be doing so as well. Some posters seem to believe that the AWD in a $40k Kia is set up the same as the AWD of supercars.

Kia's AWD should be being compared to Ford's not Buggati's.

for the record:
i am not saying that the Stinger is comparable to GTR or R8.
My point was about AWD being relevant and using some higher end cars to illustrate that point.
No one is comparing Kia's AWD to Bugatti.
Bottom line is that i prefer AWD cars for me, that's all.

 

[TimS]

Well, you have taken my very basic premise made very early on that AWD gets worse gas mileage than RWD and deflected from it. As a result, I used analogies because you were too doltish and puerile to understand it directly...

I did not 'deflect' from anything. I simply proved that your suppositions were not entirely accurate. You tried strange analogies, 'science', and various other ways to explain away my comments, and you failed each time. And I am pretty sure I understand your claims, which is why I know your claims aren't accurate in the context of this discussion.

When asked for proof - you provided none. You simply took a high-brow approach and tried to sound smarter than you are. Of course you're free to believe what you wish and mentally generate whatever MPG numbers you want - but that doesn't make your beliefs true.

My point was made specifically in response to the OP's question regarding the choice between RWD and AWD....

...between AWD and RWD STINGERS. A slightly important distinction. What evidence do you have that a RWD Stinger gets better gas mileage than an AWD Stinger? -Zero-. Evidence using -other- makes/models of vehicles.

What I provided was a real-world test by a reliable source for the -specific- models the OP had asked about, and their results do not match up with your claims.

How -hard- can this really be for you to understand?

In the past, for other models, for other brands, for other AWD technologies, there may very well have been drastic differences in gas mileage between the two systems. But this is 2018. Apparently, Kia themselves believe that their RWD and AWD vehicles have identical (or NEAR identical enough) ratings. You 'deflected' to the KIA MPG claims from 5 -years- ago. The C&D article supports my claims - and Kia's - at least for now.

It isn't about me feeling froggy or tallying up anything. It was about presenting truth.

I've never claimed that AWD gets 'better' gas mileage than RWD. Not sure where you got that idea from.

And I've provided 'truth' to you, plain and simple, yet you refuse to accept it. /shrug. Like you smugly told someone else earlier, "You can lead a horse to water..."

For some reason, you simply can't accept facts - whether you're just bullheaded, or prefer to remain ignorant - maybe both?

And for the second time - I reply to posts in the same tone in which I am spoken to. Don't like 'smug and snarky'? Then don't be a douche. It's pretty simple.

-Tim

 

[Helo58]

Yeah, not done... I simply think that the idea of misinformation being on a forum is a disservice to everyone who doesn't know the difference. Unfortunately, in this case, I feel like I am explaining that the earth is not flat to someone of a primitive civilization.

I did not 'deflect' from anything. I simply proved that your suppositions were not entirely accurate. You tried strange analogies, 'science', and various other ways to explain away my comments, and you failed each time. And I am pretty sure I understand your claims, which is why I know your claims aren't accurate in the context of this discussion.

When asked for proof - you provided none. You simply took a high-brow approach and tried to sound smarter than you are. Of course you're free to believe what you wish and mentally generate whatever MPG numbers you want - but that doesn't make your beliefs true.

Let's try this, I'll ask you direct questions that have a yes or no answer and let's see what you say. If you don't understand a question feel free to ask for clarification. Please keep in mind, these aren't nuanced questions. A simple yes or no will be sufficient. (No peeking, the answers are at the end of the test.)

1) Do you believe that manufacturer's horsepower ratings = customer dyno horsepower ratings?

2) Do you think that Kia has created a 100% efficient RWD drivetrain for the Stinger?

3)Do you think that Kia has created a 100% efficient AWD drivetrain for the Stinger?

4) Do you believe that drivetrain efficiency affects the possible difference in horsepower mentioned in question #1?

5) If the answer to question 4 is no, using another causation, can you account for any difference in between the manufacturer's horsepower rating and customer dyno horsepower rating as mentioned in question #1?

6) If there is no difference between the drivetrain efficiencies for AWD and RWD, would you contend that both AWD and RWD are 100% efficient?

7) If both systems are less than 100% efficient but still equal, can you explain the reduction in efficiency from 100%?

8) Do you believe drivetrain efficiency affects fuel economy?

9) If you answered yes to question 8, do you believe it is possible for two comparable Stingers with different drivetrain efficiencies to have the same fuel economy?

10) If you answered yes to #9, can you account for how a Stinger with a less efficient drivetrain can achieve the same fuel economy as the Stinger with the more efficient drivetrain.

...between AWD and RWD STINGERS. A slightly important distinction. What evidence do you have that a RWD Stinger gets better gas mileage than an AWD Stinger? -Zero-. Evidence using -other- makes/models of vehicles.

What I provided was a real-world test by a reliable source for the -specific- models the OP had asked about, and their results do not match up with your claims.

How -hard- can this really be for you to understand?

In the past, for other models, for other brands, for other AWD technologies, there may very well have been drastic differences in gas mileage between the two systems. But this is 2018. Apparently, Kia themselves believe that their RWD and AWD vehicles have identical (or NEAR identical enough) ratings. You 'deflected' to the KIA MPG claims from 5 -years- ago. The C&D article supports my claims - and Kia's - at least for now.

This is taken from "the official U.S. government source for fuel economy information." If you notice, there is a 1mpg difference in city mileage. Other 2019 AWD/RWD Kia models show differences between EPA ratings for AWD/RWD. They all favor the RWD model. Furthermore, other manufacturers also show mileage differences between the AWD/RWD favoring the RWD. A reminder that this 1mpg represents a 5%-7% difference between the AWD/RWD Stingers.

I've never claimed that AWD gets 'better' gas mileage than RWD. Not sure where you got that idea from.

Okay, granted. Is it safe to say that you have contended that there is no difference in AWD/RWD mileage? If so, please present one piece of evidence from any website or forum that states that there is no mileage "penalty" for an AWD drivetrain.

I
When asked for proof - you provided none. You simply took a high-brow approach and tried to sound smarter than you are. Of course you're free to believe what you wish and mentally generate whatever MPG numbers you want - but that doesn't make your beliefs true.

There is no easy way to "prove" that AWD Stingers cars are less fuel efficient than RWD Stingers. It would require removing the engine, dyno'ing the engine at the crank, reinserting the engine and then dyno'ing it in the car. Both tests would be conducted under load. The difference between the two would be attributable to drive train loss. But there are tons of empirical methods to confirm the efficiency differences. Here are a few...

Drivetrain Power Loss - The 15% "Rule"- Modified Magazine

Drivetrain losses (efficiency) – x-engineer.org

If you are too busy to read the articles, here are some pictures. The caption of the first is the relevant part. The last paragraph of the second is the relevant part.






There is no shortage of more stuff like that. However, I was unable to find anything that said the efficiencies were the same between AWD and RWD of ANY make or manufacturer.

As promised, here are the correct answers to the questions at the top:


1) Do you believe that manufacturer's horsepower ratings = customer dyno horsepower ratings?
No, the ratings do not equal each other due to drivetrain losses. This varies by drivetrain. Most efficient to least efficient: FWD, RWD, AWD/4WD

2) Do you think that Kia has created a 100% efficient RWD drivetrain for the Stinger?
No, there is no such thing as a 100% RWD drivetrain. If there was, the horsepower ratings in question 1 would be equal.

3)Do you think that Kia has created a 100% efficient AWD drivetrain for the Stinger?
No, there is no such thing as a 100% AWD drivetrain. If there was, the horsepower ratings in question 1 would be equal.

4) Do you believe that drivetrain efficiency affects the possible difference in horsepower mentioned in question #1?
Yes, this is cause as determined by the SAE and other industry professionals.

5) If the answer to question 4 is no, using another causation, can you account for any difference in between the manufacturer's horsepower rating and customer dyno horsepower rating as mentioned in question #1?
There is no other reason for a difference in Hp ratings when an engine is tested out of the car and then tested in the car connected to the drivetrain.

6) If there is no difference between the drivetrain efficiencies for AWD and RWD, would you contend that both AWD and RWD are 100% efficient?
No drivetrains are 100% efficient. This is a physical impossibility.

7) If both systems are less than 100% efficient but still equal, can you explain the reduction in efficiency from 100%?
It is a physical impossibility for any AWD and RWD Stinger to have the same efficiency provided they are maintained and in proper working order.

8) Do you believe drivetrain efficiency affects fuel economy?
Drivetrain losses are a key factor in determining fuel economy. Driving style, aerodynamics, tire type/size/inflation, etc. are other considerations.

9) If you answered yes to question 8, do you believe it is possible for two comparable Stingers with different drivetrain efficiencies to have the same fuel economy?
Identical Stingers, with the only exception being the drivetrain (AWD/RWD), will have different fuel economies in proportion to driveline efficiency differences.

10) If you answered yes to #9, can you account for how a Stinger with a less efficient drivetrain can achieve the same fuel economy as the Stinger with the more efficient drivetrain.
It is a physical impossibility for any AWD and RWD Stinger to have the same fuel economy provided they are maintained and in proper working order.

 

[westcoastGT]

............bawaaaaa . You sir are obsessed ! Kudos for all the time and patience to put that post together ! WINNER !!

 

[Kamauxx]

Thats probably the longest post ever posted on a Saturday to any forum ever.

 

[westcoastGT]

O

Thats probably the longest post ever posted on a Saturday to any forum ever.

OCD ???? Bawaaaa !!!

 

[Helo58]

O

OCD ???? Bawaaaa !!!

Hey, I have already sorted the canned foods in my pantry by height and fiber content, calibrated my toilet to exactly 2.15 gallons per flush, and divided up my sour patch kids by color and placed them in separate bags. What else was I going to do on a rainy Saturday?

 

[westcoastGT]

Thats probably the longest post ever posted on a Saturday to any forum ever.

OCD ??? Bawaaaaaa

Hey, I have already sorted the canned foods in my pantry by height and fiber content, calibrated my toilet to exactly 2.15 gallons per flush, and divided up my sour patch kids by color and placed them in separate bags. What else was I going to do on a rainy Saturday?

bawaaaaaa , love you buddy !!

 

[TimS]

Yeah, not done... I simply think that the idea of misinformation being on a forum is a disservice to everyone who doesn't know the difference. Unfortunately, in this case, I feel like I am explaining that the earth is not flat to someone of a primitive civilization.

Done - not done. Hilarious. Alright then - let's dig in! You're trying to teach me that the world isn't flat, and I'm trying to teach you that the sun does not revolve around the earth. LOL

1) Do you believe that manufacturer's horsepower ratings = customer dyno horsepower ratings?..... etc.

Your preconceived notions of what 'should be' may or may not match up with real-world results. That's the -simplest- part of this entire debate that you are not understanding.

In many cases, AWD vehicles may very well experience drastically worse MPG then their same-model RWD counterpart. Sometimes that difference may be smaller. In the Stinger's case, based on -evidence-, the difference is 'small to none'.

Ask all the 'questions' you want. Make all the claims you want. And heck - toss out some more analogies if you want. None of your 'beliefs' change the actual evidence provided so far - whether you happen to like the results or not.

This is taken from "the official U.S. government source for fuel economy information." If you notice, there is a 1mpg difference in city mileage. Other 2019 AWD/RWD Kia models show differences between EPA ratings for AWD/RWD. They all favor the RWD model. Furthermore, other manufacturers also show mileage differences between the AWD/RWD favoring the RWD. A reminder that this 1mpg represents a 5%-7% difference between the AWD/RWD Stingers.

....which matches with my claims. "Small to none". I never claimed they were 100% equivalent, and I certainly never claimed that AWD was superior. But a difference of 0-1 MPG is minuscule - which, again, matches everything I've said.

Okay, granted. Is it safe to say that you have contended that there is no difference in AWD/RWD mileage?

I did not claim there was 'no difference' 100% of the time. In fact, I've gone through great lengths to explain, repeatedly, that the difference is SMALL TO NONE. That, by definition, means there is room for variance. That does not magically equate to 'no difference whatsoever'. I still, for the life of me, do not see how you can not grasp this. 'Small to none' means just that.

If so, please present one piece of evidence from any website or forum that states that there is no mileage "penalty" for an AWD drivetrain.

I already did. The C&D test indicated a variance of 'small to none'. The difference is small enough that Kia themselves has indicated the same MPG ratings for both platforms. I've only ever used those as my two sources, and you know this. There are no other magical websites that state AWD and RWD MPG is always identical (that I am aware of), and, again, I never made such a claim.

You also quoted fueleconomy.gov - which very clearly displays AWD and RWD MPG for highway driving to be identical. According to your assertions - that is simply not possible.

If you want to disagree with Kia, C&D, and a website you quoted yourself, that's cool. Since the OP was asking about -Stingers- specifically, I provided actual data for the -specific- model, including a real-world test. Your data is based on general data from across the spectrum. While your data may technically be correct, it would seem that there is data that conflicts with that, but the data I provided is -specific to the Stinger-.

So far, Stinger RWD and AWD MPG differences have been found to be 'small to none'. I've invited you to provide test data -specifically for the Stinger- that shows otherwise and I am still waiting to see it.

There is no easy way to "prove" that AWD Stingers cars are less fuel efficient than RWD Stingers. It would require removing the engine, dyno'ing the engine at the crank, reinserting the engine and then dyno'ing it in the car. Both tests would be conducted under load. The difference between the two would be attributable to drive train loss. But there are tons of empirical methods to confirm the efficiency differences. Here are a few...

Irrelevant. What you propose does not equate to 'real world tests'. I would wager most of us do not remove our engine, dyno it, re-insert the engine and then dyno it in the car for -any- reason. That's not 'real world'. A 'real world' test is taking the vehicle out and using it in a manner that a typical driver would, recording the results, and comparing. That's what C&D did. That's all I claimed they did. They did this in spite of Kia's MPG claims, and as mentioned, C&D even found their own results to be slightly higher (for both models) than Kia listed. Was it a fluke? Was it evidence that Kia is being more conservative in their own estimates? Was it the driver driving the AWD model more conservatively than the RWD model? All reasonable questions. What is not 'reasonable' is every single owner of every single AWD/RWD Stinger looking for their nearest available dyno.

How do you think Kia came up with their own numbers? Do you assert they are fabricating them - after the incident 5 years ago? One would think that being under such scrutiny and facing financial penalties, Kia would make the effort to be more accurate with their numbers. But - maybe not? I do not own a multi-million/billion dollar company, so maybe you're right, and maybe their numbers are way off and they simply roll a dice and use those numbers to generate their ratings. But if the RWD and AWD difference in MPG was as drastically different as you seem to think, I would wager Kia would have AT LEAST noted a 1 mpg difference on their own estimates?

Even the link to fueleconomy.gov that you provided confirms what I've said all along. In fact, Highway driving is identical, which based on your assertions - should be impossible. The 1 MPG difference for the city rating is the smallest recognizable difference (at least I don't see any rating variations of less than 1 MPG, but I admit I didn't look long). Furthermore, their combined rating is ALSO identical, and the estimated annual fuel costs (which you conveniently cropped from your post) - from the site YOU referenced - is also IDENTICAL.

In the end - any reasonable person would agree that fits the definition of SMALL TO NONE.

-Tim

 

[westcoastGT]

Done - not done. Hilarious. Alright then - let's dig in! You're trying to teach me that the world isn't flat, and I'm trying to teach you that the sun does not revolve around the earth. LOL



Your preconceived notions of what 'should be' may or may not match up with real-world results. That's the -simplest- part of this entire debate that you are not understanding.

In many cases, AWD vehicles may very well experience drastically worse MPG then their same-model RWD counterpart. Sometimes that difference may be smaller. In the Stinger's case, based on -evidence-, the difference is 'small to none'.

Ask all the 'questions' you want. Make all the claims you want. And heck - toss out some more analogies if you want. None of your 'beliefs' change the actual evidence provided so far - whether you happen to like the results or not.



....which matches with my claims. "Small to none". I never claimed they were 100% equivalent, and I certainly never claimed that AWD was superior. But a difference of 0-1 MPG is minuscule - which, again, matches everything I've said.



I did not claim there was 'no difference' 100% of the time. In fact, I've gone through great lengths to explain, repeatedly, that the difference is SMALL TO NONE. That, by definition, means there is room for variance. That does not magically equate to 'no difference whatsoever'. I still, for the life of me, do not see how you can not grasp this. 'Small to none' means just that.



I already did. The C&D test indicated a variance of 'small to none'. The difference is small enough that Kia themselves has indicated the same MPG ratings for both platforms. I've only ever used those as my two sources, and you know this. There are no other magical websites that state AWD and RWD MPG is always identical (that I am aware of), and, again, I never made such a claim.

You also quoted fueleconomy.gov - which very clearly displays AWD and RWD MPG for highway driving to be identical. According to your assertions - that is simply not possible.

If you want to disagree with Kia, C&D, and a website you quoted yourself, that's cool. Since the OP was asking about -Stingers- specifically, I provided actual data for the -specific- model, including a real-world test. Your data is based on general data from across the spectrum. While your data may technically be correct, it would seem that there is data that conflicts with that, but the data I provided is -specific to the Stinger-.

So far, Stinger RWD and AWD MPG differences have been found to be 'small to none'. I've invited you to provide test data -specifically for the Stinger- that shows otherwise and I am still waiting to see it.



Irrelevant. What you propose does not equate to 'real world tests'. I would wager most of us do not remove our engine, dyno it, re-insert the engine and then dyno it in the car for -any- reason. That's not 'real world'. A 'real world' test is taking the vehicle out and using it in a manner that a typical driver would, recording the results, and comparing. That's what C&D did. That's all I claimed they did. They did this in spite of Kia's MPG claims, and as mentioned, C&D even found their own results to be slightly higher (for both models) than Kia listed. Was it a fluke? Was it evidence that Kia is being more conservative in their own estimates? Was it the driver driving the AWD model more conservatively than the RWD model? All reasonable questions. What is not 'reasonable' is every single owner of every single AWD/RWD Stinger looking for their nearest available dyno.

How do you think Kia came up with their own numbers? Do you assert they are fabricating them - after the incident 5 years ago? One would think that being under such scrutiny and facing financial penalties, Kia would make the effort to be more accurate with their numbers. But - maybe not? I do not own a multi-million/billion dollar company, so maybe you're right, and maybe their numbers are way off and they simply roll a dice and use those numbers to generate their ratings. But if the RWD and AWD difference in MPG was as drastically different as you seem to think, I would wager Kia would have AT LEAST noted a 1 mpg difference on their own estimates?

Even the link to fueleconomy.gov that you provided confirms what I've said all along. In fact, Highway driving is identical, which based on your assertions - should be impossible. The 1 MPG difference for the city rating is the smallest recognizable difference (at least I don't see any rating variations of less than 1 MPG, but I admit I didn't look long). Furthermore, their combined rating is ALSO identical, and the estimated annual fuel costs (which you conveniently cropped from your post) - from the site YOU referenced - is also IDENTICAL.

In the end - any reasonable person would agree that fits the definition of SMALL TO NONE.

-Tim

.......and Tim you get a big hug too ! ...............great debate and good entertainment

 

[Helo58]

....which matches with my claims. "Small to none". I never claimed they were 100% equivalent, and I certainly never claimed that AWD was superior. But a difference of 0-1 MPG is minuscule - which, again, matches everything I've said.

One man's "miniscule" is another man's 5%-7%. A 5%-7% difference easily falls within the possible added driveline efficiency loss resulting from the additional gearing (transfer case, etc.) of the AWD system. 5%-7% (1mpg to you) is the only amount I have ever maintained.

Hold on! Did we just agree?? What?? No?? Awww man. Got my hopes up...

Irrelevant. What you propose does not equate to 'real world tests'. I would wager most of us do not remove our engine, dyno it, re-insert the engine and then dyno it in the car for -any- reason. That's not 'real world'. A 'real world' test is taking the vehicle out and using it in a manner that a typical driver would, recording the results, and comparing. That's what C&D did. That's all I claimed they did. They did this in spite of Kia's MPG claims, and as mentioned, C&D even found their own results to be slightly higher (for both models) than Kia listed. Was it a fluke? Was it evidence that Kia is being more conservative in their own estimates? Was it the driver driving the AWD model more conservatively than the RWD model? All reasonable questions. What is not 'reasonable' is every single owner of every single AWD/RWD Stinger looking for their nearest available dyno.

I should have been clearer. Real-world tests to me are tests done on dynos with real engines or on the highway. When compared to calculations and charts for determining driveline loss theoretically, the difference should be apparent. I considered the "world" and the "lab" as the two things being compared. My apologies for not making this distinction clearer. I agree with you and thought I made it clear that removing the engine, etc. is not feasible and would be quite cumbersome. However, it remains the only true test that could minimize variables to the extent that would allow a conclusive finding. The point you made with respect to driving style influencing the test can be furthered. Did the cars have the same tires with the same air pressure, were they at the same operating temperature, were they operating in the same environment (air temp, humidity, precipitation, etc.), did they have the same oil in the engine, was the drive mode selected in the Stinger the same, etc. The list could be limitless which is precisely why the C&D test you referenced doesn't instill a lot of confidence and should be taken lightly. The cumbersome example of measuring Hp at the crank and then at the wheels under lab conditions on a dyno and subsequently validating the findings on the highway in tightly controlled testing is the only conclusive way to determine driveline loss.

How do you think Kia came up with their own numbers? Do you assert they are fabricating them - after the incident 5 years ago? One would think that being under such scrutiny and facing financial penalties, Kia would make the effort to be more accurate with their numbers. But - maybe not? I do not own a multi-million/billion dollar company, so maybe you're right, and maybe their numbers are way off and they simply roll a dice and use those numbers to generate their ratings. But if the RWD and AWD difference in MPG was as drastically different as you seem to think, I would wager Kia would have AT LEAST noted a 1 mpg difference on their own estimates?

Kia (and every other manufacturer) comes up with its own numbers by testing their cars to the appropriate EPA test standard. This testing is done by Kia and reported to the EPA. The EPA does spot checks to ensure compliance and accuracy with the number supplied by car manufacturers. Kia got caught manipulating the numbers to the high side and was penalized for their troubles earlier this decade. Since you asked, If I were a betting man, I would think that Kia probably errs on the conservative side now when reporting their numbers, not wanting to be penalized again anytime soon.

It should be pointed out, that the test methodology may or may not benefit certain types of vehicles. Many in the industry seem to support the idea that for one, that the methodology favors smaller displacement, FI engines. The engine management software in these engines is programmed to perform well in critical areas on the test, not necessarily in every aspect, just the areas highlighted in the test. Kia may have an engine/transmission management strategy that also the "games" the test in similar fashion to achieve their stated MPG numbers for the AWD and RWD Stinger. Kia's EPA numbers may make the similarity greater than it actually is in a non-test environment. I can't prove it, but I can't disprove it either.

Even the link to fueleconomy.gov that you provided confirms what I've said all along. In fact, Highway driving is identical, which based on your assertions - should be impossible. The 1 MPG difference for the city rating is the smallest recognizable difference (at least I don't see any rating variations of less than 1 MPG, but I admit I didn't look long). Furthermore, their combined rating is ALSO identical, and the estimated annual fuel costs (which you conveniently cropped from your post) - from the site YOU referenced - is also IDENTICAL.

Again, the EPA numbers are the results from specific tests that may or may not represent real world driving and mileage results.

Below are the test methods that supplement FTP-72 and FTP-75:
US EPA altered the testing procedure effective MY2008 which adds three new Supplemental Federal Test Procedure (SFTP) tests to include the influence of higher driving speed, harder acceleration, colder temperature and air conditioning use.[62]

SFTP US06 is a high speed/quick acceleration loop that lasts 10 minutes, covers 8 miles (13 km), averages 48 mph (77 km/h) and reaches a top speed of 80 mph (130 km/h). Four stops are included, and brisk acceleration maximizes at a rate of 8.46 mph (13.62 km/h) per second. The engine begins warm and air conditioning is not used. Ambient temperature varies between 68 °F (20 °C) to 86 °F (30 °C).

SFTO SC03 is the air conditioning test, which raises ambient temperatures to 95 °F (35 °C), and puts the vehicle's climate control system to use. Lasting 9.9 minutes, the 3.6-mile (5.8 km) loop averages 22 mph (35 km/h) and maximizes at a rate of 54.8 mph (88.2 km/h). Five stops are included, idling occurs 19 percent of the time and acceleration of 5.1 mph/sec is achieved. Engine temperatures begin warm.

Lastly, a cold temperature cycle uses the same parameters as the current city loop, except that ambient temperature is set to 20 °F (−7 °C).

EPA tests for fuel economy do not include electrical load tests beyond climate control, which may account for some of the discrepancy between EPA and real world fuel-efficiency. A 200 W electrical load can produce a 0.4 km/L (0.94 mpg) reduction in efficiency on the FTP 75 cycle test.[29]

Personally, I got 31mpg on my last trip to the beach. It exceeds the Kia EPA sticker number by 6mpg. This exceeds the test methodology results stated by Kia by 20%. It is my contention that the numbers Kia provides as EPA numbers simply reflect a value that will allow them to pass an EPA spot check, not a true representation of the actual mileage potential. There is simply not enough known about how Kia determines the EPA numbers for the Stinger AWD/RWD to say this with any certainty.

The key point here is that the EPA numbers are not the test results. They are the numbers with zero decimal places derived from the test results that Kia wants to put out as their statement of the estimated mileage. For previously stated reasons, these numbers can be overstated or understated based on Kia's confidence in passing a spot check. They are not test results and should not be used as such. Explicitly put, the EPA sticker is not a reflection of the actual fuel economy differences between and AWD and RWD Stinger. It is simply a number that Kia sets, in order to be in compliance with EPA testing.

In the end - any reasonable person would agree that fits the definition of SMALL TO NONE.
-Tim

In the end, there is nothing in the EPA numbers or the C&D test that allow you to conclusively determine (or even suggest as far as I am concerned) that the AWD/RWD Stinger mileage difference is small to none. There is a mountain of available evidence that suggests it is larger than small to none.

 

[MerlintheMad]

 

[TimS]

One man's "miniscule" is another man's 5%-7%. A 5%-7% difference easily falls within the possible added driveline efficiency loss resulting from the additional gearing (transfer case, etc.) of the AWD system. 5%-7% (1mpg to you) is the only amount I have ever maintained.

I find it interesting that even with the slight city MPG difference on the website you listed, the annual estimated fuel costs were identical (for both 2018 and 2019 models of both flavors). Will they always be identical? Of course not. Could they be sometimes? Sure. A 1MPG difference is the smallest difference reported (that I could find).

But if 1 MPG difference is the smallest measurable difference, I don't see how someone would reasonably call that anything else but 'small'.
Apparently to the staff at C&D, it falls into the "small to none" category, and that's reasonable enough to me.

I should have been clearer. Real-world tests to me are tests done on dynos with real engines or on the highway...

Obviously I am not a mechanic - and I don't think most drivers are, either. I would also guess that the layman doesn't even know what a 'dyno' looks like. But I -do- believe nearly every driver who owns a vehicle actually -drives- it, and to me that is a far more accurate 'real world' test than taking the engine out and slapping it on a dyno, or putting the vehicle itself on a dyno. Does the dyno simulate all the different driving conditions that you and I have both described? A 'real world' setting is one that takes into consideration all those details, at least to me. I believe most drivers will be driving their vehicles in situations closer to those presented in the C&D article, than the conditions presented by a dyno. (edit - I just read the bit about the testing on the fueleconomy website you linked. Apparently the dyno tests do take into account wind-resistance and weight, but I don't see any other criteria listed).

Since you asked, If I were a betting man, I would think that Kia probably errs on the conservative side now when reporting their numbers, not wanting to be penalized again anytime soon.

That would be my same bet, as well (Yes, we can agree on some things!). The C&D article reported slightly higher findings, which would support our bets. But if we are right, why would they misrepresent the numbers they discovered between the RWD/AWD models? Or maybe it's just laziness on their part? Not wanting to hurt sales of one model over the other? Speculation of course - but it's also reasonably possible that their results were accurately reported.

In the end, there is nothing in the EPA numbers or the C&D test that allow you to conclusively determine (or even suggest as far as I am concerned) that the AWD/RWD Stinger mileage difference is small to none. There is a mountain of available evidence that suggests it is larger than small to none.

Fair enough. As I've stated from the beginning, my opinion is simply based on -available- evidence. If that available data is not yet enough for you to agree with at this time - that's certainly your call.

-Tim