Gas. 87, 91, 93 Octane?

[bugaboo90]

Costco membership is $60, right?

If anyone has a Costco near them, try to compare gas prices and see if the $30 membership is worth it for you. For me, Costco premium around me is about 30c cheaper than the cheapest Shell or BP around me, which equates to around $130 saved/year, so that $30 goes a long way. And since they're Top Tier, you don't need to worry about fuel quality.

 

[SteveCo]

Costco membership is $60, right?

Yeah, but with it you can get a 45 gallon drum of pickles for like 3 bucks ...

 

[Berzerker]

Costco membership is $60, right?

Oh my bad, yeah. I split my membership with a friend, so we paid $30 each, which is where I got it from.

So yeah, even $60 is still good, but $30 with splitting it is better.

 

[davebo]

Yeah, but with it you can get a 45 gallon drum of pickles for like 3 bucks ...

I knew it'd pay off that I rigged my Stinger to run on pickle brine. Improved my mileage 17% and now my car smells like lunchtime.

 

[StungBlueGT2]

I appreciate all the math you put into the post, and your comparison to an Olympic athlete works when we're at the track or driving aggressively on public roads, but it's not so apt when people are facing a long highway road trip or boring commute to work. A better analogy would be an Olympic athlete having a cereal bar for breakfast instead of a properly cooked and nutritionally balanced meal on a day that they have nothing special planned at all, maybe just a routine workout. As for who would buy the Stinger then put regular gas in it to save money, I guess anyone who was considering the Buick Regal GS but thought it had too little power, and there weren't any other liftback sedans available in that price range with 320-350hp. That's the sort of gap in the market Kia was here to fill, but within any market gap there's gonna be some wiggle room. You could just as well ask why anyone is putting LAP3 chips to get their Stingers over 400hp instead of just buying a faster car to begin with. I imagine the reasons are numerous.

You’re welcome and I understand your analogy, but that version is missing half my point. A cereal bar is somewhat healthy and probably would still be part of their “recommended” diet. That would be like running mid grade 89 octane at least. I’m only talking about users of lower quality 87 octane that insist on ignoring manufacturers recommendations. 87 almost always has less additives(leaves 19 times more carbon buildup)and will negatively effect engine performance, efficiency and longevity. I feel this equates to a closer comparison of an athlete "occasionally" eating junk food which would still have those compounding negative effects, especially over repeated uses.

The fact is that our Stingers were built to run on premium fuel. Just because the ECU has the ability to protect itself from poorer fuel and retard timing doesn’t mean it should be used that way. This is simply a defense mechanism of the engine management system, and NOT how it was designed to operate. IMO you shouldn’t purposely go against manufacturers recommendations and potential cause combustion issues just because its possible.

In reference to the the Buick GS, I think you may have misunderstood the point of my question. I agree there is a wide market gap the Stinger is covering and there are less powerful alternatives to the Stinger. However the Buick GS is still designed as "GrandSport" performance car with priorities focused on power, not economy. If saving a few bucks on fuel was a deciding factor, then why not get a more economical car like the 2.0L Stinger?

Again no offense to anyone, but I just dont understand the purpose of paying $6k-$20k more to get a high performance 3.3TT, but then try to save a few bucks using fuel that negative effects the performance you paid extra for in the first place.

Mysteries of the universe I guess and just trying to help educate people on the negatives of 87 octane so they don't create future problems for themselves.

 

[Marc Collins]

The fact is that our Stingers were built to run on premium fuel. Just because the ECU has the ability to protect itself from poorer fuel and retard timing doesn’t mean it should be used that way. This is simply a defense mechanism of the engine management system, and NOT how it was designed to operate. IMO you shouldn’t purposely go against manufacturers recommendations and potential cause combustion issues just because its possible.

First, we are not sure about that. The manuals state 87 octane, but some are being updated with stickers that say 91 is "Recommended." If you read and believe the AAA studies above (hope this is the right thread that they are in because there is more than one discussing the same topic!), and other sources, you would conclude that anything above 87 is either a total waste, or, to be a bit more generous, only needed for extreme heat or towing or track days, etc.

Second, there are lots of debates about this all over the net--nothing special about Stinger. If there is actual evidence showing that turbocharged cars are more likely to gain from premium when it is not required, only recommended, please present it here as it will be helpful to the debate. False claims that the Stinger is built to use premium when ALL evidence we have from KIA so far says not, will not help the debate. The AAA studies did not sample enough different vehicles to be 100% conclusive. They only puncture the usual myths that premium is automatically better and worth paying extra for, which it is not except in rare cases or circumstances (according to that study and others).

 

[davebo]

I think one of the biggest problems in our country right now is people's inability to get in the headspace of other people and understand things from their point of view. You say regular gas is going to leave 19x more carbon buildup for users of lower quality 87 octane, but Top Tier Gas with additives isn't going to seize your engine up after a decade, and those brands cover the vast majority of gas stations in America. I know we've shelled out for an expensive car with 365 horsepower, but not understanding that some people may rather save some money than have that last 15 or so hp for their traffic commuting or highway road trips seems willfully obtuse. I'm all for disagreeing with their perspective, but is it really difficult to understand it? It's not like a Stinger GT running regular is slower than a 2.0t, or anywhere close to it. Believe me, if my car had the option to turn off half the cylinders and use ~180hp to save me some gas money, I'd turn that option on anytime I had to sit on the D.C. beltway in stop and go traffic. In fact I'll wager there are quite a few people who bought a GT2 just for the nappa leather and will never take the Stinger over 80mph.

I might disagree, but I can even see the perspective of people who willfully buy the cheapest grossest bargain basement regular fuel that will leave deposits and ruin an engine. They're called leasers and they don't give a crap about the car after the first three years

 

[Marc Collins]

I think one of the biggest problems in our country right now is people's inability to get in the headspace of other people and understand things from their point of view. You say regular gas is going to leave 19x more carbon buildup for users of lower quality 87 octane, but Top Tier Gas with additives isn't going to seize your engine up after a decade, and those brands cover the vast majority of gas stations in America. I know we've shelled out for an expensive car with 365 horsepower, but not understanding that some people may rather save some money than have that last 15 or so hp for their traffic commuting or highway road trips seems willfully obtuse. I'm all for disagreeing with their perspective, but is it really difficult to understand it? It's not like a Stinger GT running regular is slower than a 2.0t, or anywhere close to it. Believe me, if my car had the option to turn off half the cylinders and use ~180hp to save me some gas money, I'd turn that option on anytime I had to sit on the D.C. beltway in stop and go traffic. In fact I'll wager there are quite a few people who bought a GT2 just for the nappa leather and will never take the Stinger over 80mph.

I might disagree, but I can even see the perspective of people who willfully buy the cheapest grossest bargain basement regular fuel that will leave deposits and ruin an engine. They're called leasers and they don't give a crap about the car after the first three years

Honda and others have used cylinder deactivation for years for exactly that reason. Add me to the list. I'd rather have that than idle stop and go because it is affecting the engine when it's actually consuming a lot of fuel...in motion...compared to when stopped when it uses very little.

 

[bugaboo90]

Based on the recommendation about, I did become a costco member. Their premium prices are a decent amount less then other places and with a bmw and stinger both using premium, I think the membership will easily pay for itself.

Thank you for the suggestion.

 

[Soca Boy]

I find myself using Shell V-Power.

 

[Clearly Canadian]

Most of Canada is cold and requires winter tires and a change in driving behaviour for half the year. There’s no way I’m going to use the vehicle’s peak performance during this time.

There’s a significant gap in price between 91 and 87 octane, so an incentive exists to use a lower octane if possible.

I’ve been gradually experimenting with blending octanes of Top Tier gas until I was down to pure 87. And I have to say, my butt doesn’t notice any difference in performance.

I think I’ll use 87 all winter. Figure I’ll save a couple hundred dollars.

I’ve been using 91 octane for the past decade in my previous car. I’m sure there’s a calculable performance difference, I just can’t tell when driving it.

 

[SilverNitr8]

I was using 87 then switched to 91 and noticed no improvements in mileage. I only use top tier gas on this car so it's either Shell, Exon, or Sunnoco (if I can't find a Shell or Exxon). So here's my conclusion, stick with top tier gas. For normal day to day driving, I would stick to 87, or 89. If I am going on a long trip with mostly highway speed, I'd use 91. Right now my average MPG is hovering around 14-15 MPG in both 87 or 91. I've been unable to achieve the 21 MPG city driving. I'm also in Northern VA where traffic always suck balls. To get around 17 MPG, I would have to be very careful with my acceleration, but what fun is that? This car is meant to be driven.

 

[MisterMac]

Opinions are not facts.

The facts are:

Top tier gas has been proven to keep the engine valves cleaner.
The individual buyer gets to decide whether top tier gas is worth the additional expense.
The Kia Stinger requires gasoline with a minimum octane rating, of 87, unless you are at a higher elevation.
The Stinger engines can use 91 Octane gasoline and in doing so will put out about 2.2% more hp.
If the owner/driver desires that additional 2.2% hp, 91/93 Octane (premium) gasoline is recommended.
You may run higher Octane at your wallet's loss, however, without an after market tune your stock programmed torque curves and ignition timing cannot adjust to utilize it because they are limited to minimize warrantable damage.

 

[Marc Collins]

The facts are:

The Stinger engines can use 91 Octane gasoline and in doing so will put out about 2.2% more hp.
If the owner/driver desires that additional 2.2% hp, 91/93 Octane (premium) gasoline is recommended.

What is the source of this information? And since you seem to know things KIA has refused to disclose, 2.2% relative to what? Are the Stinger's advertised power ratings based on the minimum octane (87) or the recommended octane (91)? Please also provide sources for your "facts."

 

[rocket23]

Picked up a 3.3 rwd today. Dealership is insisting it runs on 87. I'm used to 91 coming from a turbo 4cyl.

If you're using 91, please explain why

probably already posted 91 octane for me....the engine runs better and more efficiently...than using 87...and imo 93 is a waste of money

 

[MisterMac]

What is the source of this information? And since you seem to know things KIA has refused to disclose, 2.2% relative to what? Are the Stinger's advertised power ratings based on the minimum octane (87) or the recommended octane (91)? Please also provide sources for your "facts."

It's elementary, Marc.

It is typical to see 7-9 hp gains between 87 and 91 octane fuels on turbo charged engines. I choose 8 because it is in the middle. If the engine puts out 365 hp on 87 octane, 8 divided by 365 = 2.2%. 7 would be 1.9% and 9 would be 2.47%: in my book that is "about 2.2%." According to the shop foreman at my dealership, who is also the Stinger and BMW specialist, the advertised hp production was established using 87 octane in accordance to what is required per the original owners manual. I am taking his word for it because he knows everything else about this car without fail. However, let's say the 365hp was based on 91 octane fuel. I subtract 8 from 365 to get 357. Now 8/357=2.24%, still about 2.2%....

That being said, I run only premium in my GT2 AWD because I am tuned for that.

 

[Marc Collins]

It's elementary, Marc.

It is typical to see 7-9 hp gains between 87 and 91 octane fuels on turbo charged engines. I choose 8 because it is in the middle. If the engine puts out 365 hp on 87 octane, 8 divided by 365 = 2.2%. 7 would be 1.9% and 9 would be 2.47%: in my book that is "about 2.2%." According to the shop foreman at my dealership, who is also the Stinger and BMW specialist, the advertised hp production was established using 87 octane in accordance to what is required per the original owners manual. I am taking his word for it because he knows everything else about this car without fail. However, let's say the 365hp was based on 91 octane fuel. I subtract 8 from 365 to get 357. Now 8/357=2.24%, still about 2.2%....

That being said, I run only premium in my GT2 AWD because I am tuned for that.

So, not facts after all...

 

[MisterMac]

They damn sure aren't fiction.

 

[Marc Collins]

They damn sure aren't fiction.

True, but they aren't facts as you proclaim. Educated suppositions is more accurate.

Let us know when KIA releases the official output specs by octane rating (as they have for other vehicles) Only then will we have facts.

Did they develop the original specs around the original recommended 87 octane. Plausible.

But it is equally plausible that they decided to change the recommendation to 91 octane in part out of concern that the published specs (especially fuel economy) could not be achieved with 87 or would be more likely to be achieved with 91.

In between the change was the universal disappointment expressed by Stinger owners about the real-world fuel economy being so poor and below expectations. Doubt was expressed about whether the published specs were achievable. You know the history of this with Hyundai (and others). I assume?...

Wait for facts before calling things facts or criticizing others for not using facts.

And please use your connections to get KIA to cough-up the truth/facts. I have already tried and failed.

 

[Ace2Rolex]

I only use 94. Very obvious mileage gains with 94. The odd time I’ve been forced to fill up with 91 I burn through the fuel noticeably faster.

Avg 9.8L/100km @94
Avg 11L/100km @91

Not sure if this can be verified by anyone else but I keep a log on Fuelly and have definitely noticed a difference.