About Requirement for Premium Gas

[Paul32]

If your gut can detect that level of power difference, NASA needs you for some special work.

I've heard many comments about how the car feels in the different modes. That is what I refer to has gut feeling. That's the best I can do absent a dyno or Kia facts. I go with: if it feels good with 89 or non-premium, that's what I use. I haven't competed with another car for decades.

 

[Marc Collins]

I've heard many comments about how the car feels in the different modes. That is what I refer to has gut feeling. That's the best I can do absent a dyno or Kia facts. I go with: if it feels good with 89 or non-premium, that's what I use. I haven't competed with another car for decades.

The drive modes are a lot more dramatic (throttle mapping differences) than the difference in a couple of octane points. Few would be able to easily or reliably detect the difference. Maybe 87 to 93, but smaller increments not very likely.

 

[Paul32]

The drive modes are a lot more dramatic (throttle mapping differences) than the difference in a couple of octane points. Few would be able to easily or reliably detect the difference. Maybe 87 to 93, but smaller increments not very likely.

Maybe but I can tell the difference in MPG calculation.

 

[Marc Collins]

Maybe but I can tell the difference in MPG calculation.

Really, what is your result? It would take very careful stats collecting, not using the inaccurate on-board read-out to determine a difference, since we almost never drive in identical or even very, very similar conditions from one tank to the next. The difference would be so small even in laboratory conditions you are fooling yourself if you think you can measure it as an amateur out in the real world. Somewhere else on here I linked research studies that you should take a look at.

Yes, higher octane should yield better fuel economy. Is it enough to justify the extra cost?--not at all clear-cut because it is a small percentage usually lower than the percent difference in the price of the gas (was not the case in the olden days when premium was a much smaller differential). Is the extra power worth the extra cost?--who knows because we don't know how much extra power we are talking about. In some cars it is next to nothing; others a bit more. Stinger...still waiting for some real numbers instead of seat-of-the-pants musings or wishful thinking from wannabe racers.

 

[Paul32]

Really, what is your result? It would take very careful stats collecting, not using the inaccurate on-board read-out to determine a difference, since we almost never drive in identical or even very, very similar conditions from one tank to the next. The difference would be so small even in laboratory conditions you are fooling yourself if you think you can measure it as an amateur out in the real world. Somewhere else on here I linked research studies that you should take a look at.

Yes, higher octane should yield better fuel economy. Is it enough to justify the extra cost?--not at all clear-cut because it is a small percentage usually lower than the percent difference in the price of the gas (was not the case in the olden days when premium was a much smaller differential). Is the extra power worth the extra cost?--who knows because we don't know how much extra power we are talking about. In some cars it is next to nothing; others a bit more. Stinger...still waiting for some real numbers instead of seat-of-the-pants musings or wishful thinking from wannabe racers.

I've been calculating MPG for over 60 years, that's good enough for me to determine what octane gas I use. Did you not see my experiment on traveling to the West Palm Beach Cars and Coffee last week? And I don't rely on the on-board computer. I do it the old fashion way, gal. pumped into miles.

 

[Marc Collins]

I've been calculating MPG for over 60 years, that's good enough for me to determine what octane gas I use. Did you not see my experiment on traveling to the West Palm Beach Cars and Coffee last week? And I don't rely on the on-board computer. I do it the old fashion way, gal. pumped into miles.

No I didn't see it, sorry. But I already know whatever test you performed had more variation in driving and environmental conditions than the energy difference between the lower and higher octane tanks. That is always true unless you are in a lab because we're only talking about a very small (single digit) percentage.

 

[rocket23]

If your gut can detect that level of power difference, NASA needs you for some special work.

my ass detects the level of performance, just saying.

 

[SOCAL2.0]

I confess I can't tell the difference in my 2.0 and my mileage seems pretty much the same with 87 or 91. Same story MPG is primarily determined buy my driving style.

 

[eflyguy]

The term "premium" is made up by the gas companies to fool the general public into thinking it's better. The fact that higher performance engines often need higher octane to prevent pre-detonation - pinging - only perpetuates the myth.

It IS true that they often put more additives and such into the higher octane versions, but additives are only for helping control deposits, and all Top Tier rated fuel - regardless of octane - contain sufficient additives.

In recent years there has been a lot of press regarding this, but as with a great many things these days, the average consumer prefers to get their news from shares of clickbait on facebook or equally ignorant bobbleheads on mainstream media than factual sources. Few here would fall into that category, I suspect.

Most motors today are ''high compression motors.

*Engines

j/k.. despite what the terminology equivalent of a "grammar nazi" might spew, the term "Motor" has a much longer history describing the "make go" component of a contraption than "Engine," and even though language evolves over time, it doesn't negate that fact.

I will say, though, I was pretty surprised to find the LS1 in the '98 C5 my daughter and I looked at today requires "Premium" (91 or better).. a 5.7l producing about the same numbers (a little lower) as the Stinger. Thinking about it, however, I guess it makes sense. Air/Fuel ratios and quantities to produce a given amount of energy should be similar, boosted vs. naturally aspirated would still require the same compression ratio, so I checked - they are *identical*..

 

[Paul32]

No I didn't see it, sorry. But I already know whatever test you performed had more variation in driving and environmental conditions than the energy difference between the lower and higher octane tanks. That is always true unless you are in a lab because we're only talking about a very small (single digit) percentage.

Good enough for me.

 

[davebo]

the LS1 in the '98 C5 my daughter and I looked at today

Everywhere I go something reminds me of my now gone '98 C5. I really gotta change my avatar image.

 

[rocket23]

The term "premium" is made up by the gas companies to fool the general public into thinking it's better. The fact that higher performance engines often need higher octane to prevent pre-detonation - pinging - only perpetuates the myth.

It IS true that they often put more additives and such into the higher octane versions, but additives are only for helping control deposits, and all Top Tier rated fuel - regardless of octane - contain sufficient additives.

In recent years there has been a lot of press regarding this, but as with a great many things these days, the average consumer prefers to get their news from shares of clickbait on facebook or equally ignorant bobbleheads on mainstream media than factual sources. Few here would fall into that category, I suspect.



*Engines

j/k.. despite what the terminology equivalent of a "grammar nazi" might spew, the term "Motor" has a much longer history describing the "make go" component of a contraption than "Engine," and even though language evolves over time

2 Things,if I may,high compression does not equal high performance. That being said even the smallest engines these days are higher in compression than the earlier engines. respective to the auto industry. But to call out a high octane as a myth is a stretch, truth be told higher octane fuels basically delay combustion til the piston reaches tdc, and not before. The only myth AND YOU ARE RIGHT. Is the perception that higher octane equals more power. It does to the extent that it lets the engine run more efficiently ,making it more powerful , if you will. 87 octane in reality is more combustible than the higher octanes in the combustion process.

As for the press...whew, you are spot on...these bubble headed people in front of the camera have no idea what they are reading.

Grammar has never been a strong point with me I just used the term loosely. No hate here.

 

[Marc Collins]

my ass detects the level of performance, just saying.

It's obvious from your handle that NASA needs you

 

[eflyguy]

The only myth AND YOU ARE RIGHT. Is the perception that higher octane equals more power.

Agreed, that's what I mean about "the myth" - that the fuel industry uses branding and marketing to further perpetuate the perception that it's "better". Remember the cute little Chevron ads - I think that's where Lassiter got the idea for "Cars"!

Just adding - a lot of modern SMALL engines use tricks from performance engines to increase output for their relatively small size.

 

[Shockington]

Where are all these "recommended 91 octane" coming from? Mine says minimum 87. You better believe that's what's going into it in the winter, the fuel economy just tanks in the cold.

Also, my butt dyno can't tell the difference even slightly between 87 and 91. Do I need to get it calibrated?

 

[Marc Collins]

Where are all these "recommended 91 octane" coming from? Mine says minimum 87. You better believe that's what's going into it in the winter, the fuel economy just tanks in the cold.

Also, my butt dyno can't tell the difference even slightly between 87 and 91. Do I need to get it calibrated?

KIA updated the recommendation with a new manual or stickers over top of the old text in old manuals. You must have an earlier build where they didn't have a chance to put the sticker in.

 

[Shockington]

KIA updated the recommendation with a new manual or stickers over top of the old text in old manuals. You must have an earlier build where they didn't have a chance to put the sticker in.

Yes but recommended and minimum are different things. Is the new sticker minimum premium?

 

[Marc Collins]

Yes but recommended and minimum are different things. Is the new sticker minimum premium?

It's always recommended--to get the prescribed (advertised) power output and fuel economy. The car will not be harmed by 87 octane.