Curious ... who here uses 87 octane Regular gas in your 3.3t?

[colnago1331]

I

Do NOT use 87 and for quite a si.pke reason: the ex engineers at Kia have determined that 87 isn't recommended.


While the car can "correct" itself for the lowest octane fuel, it'd be foolish to do that with a GDI at the start. Once you log several tens of thousands of miles, then a lower octane MAY be ok as the carbon buildup in the combustion chamber will increase the compression ratio.

Actually, the opposite is true. Higher compression ratio = higher chance of knock, so it would make more sense to use higher octane fuel after the carbon has built up, not before.

Octane Explained: Does Premium, High-Octane Gas Boost Performance?

A recent AAA report found that American motorists wasted $2.1 billion dollars in the last year buying premium gasoline for engines designed to run on regular gas.

www.amsoil.com

And while Kia has "recommended" 87 octane fuel for max performance purposes, the 3.3L in no way requires it. Otherwise the manual would say 91 octane is required.

 

[Shockington]

I think the biggest scam is how fuel companies have the public believing that higher octane = cleaner burning fuel. Octane rating has absolutely no bearing on how cleanly a fuel burns. Or how much carbon will build up.

87 is perfectly adequate in nearly every engine as long as it contains the proper additives.

There are dozens of engineering videos and informative videos that debunk the perceived need for high octane fuels in typical engines.

On a side note, my owners manual says 87 recommended.

I run 91 when I'm running my tune and 87 in the winter, where the added ethanol can help with issues related to extreme cold temperatures. Also where the car is idling much more than it would be in the summer.

If you want to run 91 in your Stinger by all means. You're going to get peak performance at all times. But running 87 isn't going to magically destroy or harm anything.

I doubt anyone's view will be swayed though. We should be talking about which colour is the best, and why it's red.

 

[adam1991]

I think the biggest scam is how fuel companies have the public believing that higher octane = cleaner burning fuel. Octane rating has absolutely no bearing on how cleanly a fuel burns. Or how much carbon will build up.

Before the mid-90s, fuel additives weren't so strictly regulated and fuel companies had a sales strategy whereby the would put minimal cleaners (if any) in their lower octane fuels, then advertise their high octane fuel for its cleaning power--preventing carbon buildup and keeping injectors clean.

And grocery store gas used pretty much as little as they could get away with.

The feds then stepped in and created a rule for a minimum level of cleaners in all octane levels of fuel, a good level, because it's an easy way to move the world forward with regard to combustion engine efficiency.

At that point, the fuel companies were stuck with saying nothing more than "we have MORE cleaners in our Super Duper XYZ Power Ultra 93!" Never mind that those additional cleaners may or may not do anything for you.

I'm sure Shell has done plenty of research into what they can do to make their 93 octane fuel legitimately better in this regard--but how much better, or how one measures that "better," I don't know. But their goal has always been to use their additive package as a selling point, and to be able to say that they have a different and "better" additive package in their 93 octane compared even to their own lower octane fuels.

They do say that, and I'm sure it is better in some way. Meaningful to many/most? I don't know. But they can legitimately say it, from a technical standpoint.

That all being said, at THIS point all fuels have a minimum level of cleaners that serve the federal requirements, which are decent.

87 is perfectly adequate in nearly every engine as long as it contains the proper additives.

Yes. But, one man's adequate is another man's quest for more. The question is, does the engine respond differently--more power--with 91 or 93? Does it behave better, short and long term, with a diet of nothing but Shell 93 (or Costco 93)? That's not speaking to adequate. Of course it behaves adequately. Even the Acura and Lexus cars, based on their lesser Honda and Toyota brethren, behave adequately on 87 octane despite their owner's manuals maybe saying otherwise due to the snob factor.

Now, there's no question that YMMV. If you're driving a truck and towing a heavy load up a mountain in summer, you will absolutely do better with 93. Does that mean 93 is better? NO. American are stupid; they take one thing and declare it to be universally acceptable across all circumstances. No, 93 is the appropriate fuel for the situation. Not towing a heavy load with that truck? Driving it in winter? 93 is the wrong tool for the job. It will get the job done, but it will cost you more for zero benefit.

 

[MerlintheMad]

I find the idea, that my engine must compensate for a lower octane, disagreeable. That, combined with knowing that if/when I do want the max performance my car is designed to deliver, I need to use the recommended octane, is what makes me always use top tier premium gas.

Before the mid-90s, fuel additives weren't so strictly regulated and fuel companies had a sales strategy whereby the would put minimal cleaners (if any) in their lower octane fuels, then advertise their high octane fuel for its cleaning power--preventing carbon buildup and keeping injectors clean.

And grocery store gas used pretty much as little as they could get away with.

The feds then stepped in and created a rule for a minimum level of cleaners in all octane levels of fuel, a good level, because it's an easy way to move the world forward with regard to combustion engine efficiency.

At that point, the fuel companies were stuck with saying nothing more than "we have MORE cleaners in our Super Duper XYZ Power Ultra 93!" Never mind that those additional cleaners may or may not do anything for you.

I'm sure Shell has done plenty of research into what they can do to make their 93 octane fuel legitimately better in this regard--but how much better, or how one measures that "better," I don't know. But their goal has always been to use their additive package as a selling point, and to be able to say that they have a different and "better" additive package in their 93 octane compared even to their own lower octane fuels.

They do say that, and I'm sure it is better in some way. Meaningful to many/most? I don't know. But they can legitimately say it, from a technical standpoint.

That all being said, at THIS point all fuels have a minimum level of cleaners that serve the federal requirements, which are decent.


Yes. But, one man's adequate is another man's quest for more. The question is, does the engine respond differently--more power--with 91 or 93? Does it behave better, short and long term, with a diet of nothing but Shell 93 (or Costco 93)? That's not speaking to adequate. Of course it behaves adequately. Even the Acura and Lexus cars, based on their lesser Honda and Toyota brethren, behave adequately on 87 octane despite their owner's manuals maybe saying otherwise due to the snob factor.

Now, there's no question that YMMV. If you're driving a truck and towing a heavy load up a mountain in summer, you will absolutely do better with 93. Does that mean 93 is better? NO. American are stupid; they take one thing and declare it to be universally acceptable across all circumstances. No, 93 is the appropriate fuel for the situation. Not towing a heavy load with that truck? Driving it in winter? 93 is the wrong tool for the job. It will get the job done, but it will cost you more for zero benefit.

 

[colnago1331]

I find the idea, that my engine must compensate for a lower octane, disagreeable. That, combined with knowing that if/when I do want the max performance my car is designed to deliver, I need to use the recommended octane, is what makes me always use top tier premium gas.

It’s not compensating; it’s adjusting. And it adjusts itself when higher (93) octane fuel is used too.

 

[adam1991]

I find the idea, that my engine must compensate for a lower octane, disagreeable.

Don't think of it as "compensate for a lower octane". Think of it as "pulling the timing to keep the engine from grenading". Because that's its real intention. Like I said, not every octane level is appropriate for every situation. If the engineers designed max performance from the car when it's new, on a 72 degree sunny day, at sea level, with only a couple people in it, using 87 octane--then that's all you ever need. Adding octane won't do anything to make the engine make more power.

It's not like the engine is designed to do more than the rated power if you feed it gasoline it wasn't tuned for.

Digression: Could the engineers tune the system for 93 but the manufacturer says "use 87" and is happy with that for warranty purposes, and never says a word about using higher octane? Many people swear that's exactly how VW runs their hot hatches. And that's fine.

Or consider Mazda and their new Mazda 3 Turbo: 227bhp on 87, 250 on 93. Right there in the marketing materials and the owner's manual. They design it for maximum performance on 93, but are happy to continue to provide warranty coverage if you use 87. It's your choice, Mr. Consumer. Full transparency. That's the way to do it.

And then there are others who specify 91 or 93 octane and nothing else; I have no idea what happens if you show up with a grenaded engine at 5000 miles. Will they blame you for inappropriate gas? Has anyone heard of such a thing happening?

Well, back to the discussion. But if you have carbon buildup, hot weather, tracking it, high altitude, etc, etc, then the car will protect itself if the octane level isn't high enough for that situation. You'll see the power pull back. At this point higher octane would be useful for getting the engineered performance out of the engine--the same performance you got in the sea level, 72 degree day, 87 octane situation.

And consider this: even if I were tracking it I'd take Costco (or Shell) 87 any day over Jim Bob's Bait and Gas Sooper 93. It's not about octane level; it's about the quality of the additive package. No way am I stuffing the cheapest stuff Jim Bob can pay for under the table into my car. I've no doubt that my car runs WAY better on Costco 87 than it ever would on Jim Bob's Sooper 93.

So to the disappointment of the typical mouth-breathing American, it's not as simple as "93 MOAR BIGGER NUMBER! MUST BE BETTER!" Education and knowledge is a good thing. Chances are excellent, although not 100%, that the Kia engineers simply tuned it for 87 octane fuel.

For the record, given that I value quality and freshness of fuel/additive package over just a simple octane number, it's Costco for me all the way. On the odd situation I can't get Costco, I will happily pay for Shell. If neither of those is available, I'll take what I can get. That's rare.

 

[adam1991]

It’s not compensating; it’s adjusting. And it adjusts itself when higher (93) octane fuel is used too.

Sure--if the circumstances are such (high temps, straining up a hill, high altittudes, loaded down with people and luggage) that 87 octane isn't enough to keep the engine from knocking. Then it needs higher octane fuel to keep performance at the factory parameters. IOW, a stressed engine needs extra help.

But under normal commuting circumstances on a nice day? Are you saying that it will "adjust itself when 93 octane fuel is used"? That it will somehow create more power or something, on a nice day on flat ground at sea level, compared to 87?

Kia engineers designed it for certain operating parameters and says nothing else. If you have anything from Kia or anything from specific, detailed real world testing that backs up your assertion, that's what we want to see.

 

[colnago1331]

Sure--if the circumstances are such (high temps, straining up a hill, high altittudes, loaded down with people and luggage) that 87 octane isn't enough to keep the engine from knocking. Then it needs higher octane fuel to keep performance at the factory parameters. IOW, a stressed engine needs extra help.

But under normal commuting circumstances on a nice day? Are you saying that it will "adjust itself when 93 octane fuel is used"? That it will somehow create more power or something, on a nice day on flat ground at sea level, compared to 87?

Kia engineers designed it for certain operating parameters and says nothing else. If you have anything from Kia or anything from specific, detailed real world testing that backs up your assertion, that's what we want to see.

Yes - the engine will adjust itself (i.e. adjust the timing) when 93 octane is used just as it adjusts itself when 87 octane is used. And nearly every study done (see, for example, the video I included a few posts ago) has shown that when a higher octane is "recommended" the engine involved makes more power with higher octane gas than it does with lower (but still acceptable) octane gas. Are you telling me that's not true with Kia? That Kia's engineers somehow figured out how to make an engine that makes the same horsepower regardless of whether the recommended fuel is used or a lower octane fuel is used?

And since you didn't seem to read anything I wrote other than the post you quoted, if you look back you'll see that I agree with you - it's fine to use 87. I use 87. I don't know why you're being so unnecessarily confrontational.

 

[Blue Bucket]

In Korea, higher octane fuel is harder to find. I've filled up at 3 different stations on my driving route. Only one has higher octane fuel. Octane ratings aren't posted on the pump even at that place.

My take: Kia isn't going to mass produce a car that can only be filled up at a fraction of gas stations. So, reg. gas (about 87 here if my understanding is correct) is not going to harm the car. As far as performance, until we know what the car was factory tuned on, its mostly speculation...

 

[Slip_Angle]

consider this...

The lower the octane fuel, the faster it burns/releases it's energy vs. a higher octane fuel. Essentially it's more volatile and releases more energy. If that fuel is stable enough to not produce knock that overly reduces ignition timing, then it may produce more power at a given ignition advance vs a higher octane fuel. IE: A stock tune.

I did some testing several months ago on my G70 and found that in moderate ambient outside air temperatures, my G70 runs it's fastest 0-60 times on 87. Yeah, I'm surprised as well but over time and several runs at each of the following octane levels -- 87, 91 and 94 -- Dragy recorded my best times on 87 Octane. 0-60 in 4.25 stock.

Maybe one day I'll disprove this but for now these are my results.

 

[GenesisG70]

bU

Sure--if the circumstances are such (high temps, straining up a hill, high altittudes, loaded down with people and luggage) that 87 octane isn't enough to keep the engine from knocking. Then it needs higher octane fuel to keep performance at the factory parameters. IOW, a stressed engine needs extra help.

But under normal commuting circumstances on a nice day? Are you saying that it will "adjust itself when 93 octane fuel is used"? That it will somehow create more power or something, on a nice day on flat ground at sea level, compared to 87?

Kia engineers designed it for certain operating parameters and says nothing else. If you have anything from Kia or anything from specific, detailed real world testing that backs up your assertion, that's what we want to see.

Can you tell me where I can find Jim Bob's gas? I am interested in saving some dollars.

 

[adam1991]

Yes - the engine will adjust itself (i.e. adjust the timing) when 93 octane is used just as it adjusts itself when 87 octane is used.

You seem to be implying that the ECU has no fixed ceiling with regard to how it advances timing?

Are you saying that if you put racing gas in, the ECU would continue to advance timing until it hears knock?

I disagree. Most likely the engineers put a ceiling in. If so, the ECU will adjust up to that point.

If that ceiling point is the performance you get when 87 octane is used on a brand new car on a clear spring day at sea level with only the driver aboard, then going to 93 or 104 or whatever is meaningless.

On the other hand: If you use 87 on a carboned up high mile engine going up the mountain in Colorado on the hottest day of summer, fully loaded, then the ECU will pull back on timing until knock disappears. If you replace that 87 with 93 and continue up the mountain, the ECU will advance timing--up until knock appears or the programmed ceiling (if present) is hit, whichever comes first.

And nearly every study done (see, for example, the video I included a few posts ago) has shown that when a higher octane is "recommended" the engine involved makes more power with higher octane gas than it does with lower (but still acceptable) octane gas.

If the engine is designed that way, and if the car is sold that way, sure. That's what I said. Mazda is an example of that.

Are you telling me that's not true with Kia?

I'm saying I don't know if it's true. No one here has provided any documentation as such. Are you saying it's a fact that's how it is with Kia?

That Kia's engineers somehow figured out how to make an engine that makes the same horsepower regardless of whether the recommended fuel is used or a lower octane fuel is used?

you have it backwards. I said that Kia's engineers set the car up for 87 octane fuel, and that 93 octane fuel performs no differently (on a new/clean engine, sea level and flat, light load). In general, if they tell you "use 87" and make no mention of doing anything else, that's what they mean.

And like I said, Mazda says different. Mazda very specifically says that their system will take advantage of the higher octane fuel. What they mean is, "we tuned it/put the ceiling for 93 octane, but don't worry, using 87 won't hurt anything, we're absolutely controlling for that, we'll just back things down for you." Does Kia say anything like that?

Many VW owners claim that VW under-reports the specs on some of their engines. Some claim to have dyno numbers that show this. Whatever. VW has said nothing more than that their GTI puts out 228bhp on 87 octane. Like Kia, VW makes no commitments along the line of what Mazda says.

And since you didn't seem to read anything I wrote other than the post you quoted, if you look back you'll see that I agree with you - it's fine to use 87. I use 87. I don't know why you're being so unnecessarily confrontational.

Not my intention, sorry. If I read your earlier pieces, I've forgotten. I'll go back and take a look.

But really, I'm looking for something other than "I believe" when it comes to how a new Stinger behaves with different gasolines.

 

[adam1991]

bU


Can you tell me where I can find Jim Bob's gas? I am interested in saving some dollars.

Ever been to North Carolina? Or to the Illinois/Iowa border?

 

[GenesisG70]

Don't you think guys that if Kia engineers designed the Stinger only for 91 or higher it would have stated clearly in the manual as follows: DO NOT USE ANY OCTANE LOWER THAN 91 OR YOUR ENGINE WILL BE DAMAGED.... So its ok put whatever you want this cars are very reliable and well engineered even if you use a 87.

 

[adam1991]

Don't you think guys that if Kia engineers designed the Stinger only for 91 or higher it would have stated clearly in the manual as follows: DO NOT USE ANY OCTANE LOWER THAN 91 OR YOUR ENGINE WILL BE DAMAGED.... So its ok put whatever you want this cars are very reliable and well engineered even if you use a 87.

Not to mention that powertrain warranty.

Facts:

1) Mainstream manufacturers are loathe to require more than the cheapest gas. Buyers will stay away.

2) Manufacturers take pains not to overbuild or otherwise spend more money than they have to on their products.

That being said, the engineers could have built the thing to perform with 93 and simply back off with lower octane, as the Mazda does. But why not take advantage of that and market it? What benefit does NOT marketing it that way provide? Or said another way, what harm is there in marketing it that way if indeed that's the fact? I can see only a positive, like how Mazda's doing it.

Absent documentation from Kia, or a series of solidly controlled dyno runs, all roads point toward Kia meaning it when they say to use 87 octane and making no mention of better performance with 91 or 93.

In my experience, this is where the tuners come in. It should be easy enough for someone to write the ECU software that does exactly what you want. The VW/Audi world is full of tunes that require 93 octane. It's the buyer's choice as to what fuel he wants to use and therefore what tune he chooses.

 

[colnago1331]

<snip>

Absent documentation from Kia, or a series of solidly controlled dyno runs, all roads point toward Kia meaning it when they say to use 87 octane and making no mention of better performance with 91 or 93.

<snip>

you have it backwards. I said that Kia's engineers set the car up for 87 octane fuel, and that 93 octane fuel performs no differently (on a new/clean engine, sea level and flat, light load). In general, if they tell you "use 87" and make no mention of doing anything else, that's what they mean.

In fact, Kia does say - in the owner's manual - that using fuel with a lower octane rating than 91 "could result in loss of engine power and increase in fuel consumption," and that Kia recommends using 91 for "optimal engine performance." Moreover, my manual makes no mention of 87 octane . . . only 91 octane. What this tells me is that the engine was designed to run on 91 gas. But because this is only a recommendation, and not a requirement, there is no harm to be done in running it on 87 (other than a possible loss of power and increase in fuel consumption).

 

[MerlintheMad]

For the record, given that I value quality and freshness of fuel/additive package over just a simple octane number, it's Costco for me all the way. On the odd situation I can't get Costco, I will happily pay for Shell. If neither of those is available, I'll take what I can get. That's rare.

This my exact philosophy.

 

[Slip_Angle]

View attachment 53670

In fact, Kia does say - in the owner's manual - that using fuel with a lower octane rating than 91 "could result in loss of engine power and increase in fuel consumption," and that Kia recommends using 91 for "optimal engine performance." Moreover, my manual makes no mention of 87 octane . . . only 91 octane. What this tells me is that the engine was designed to run on 91 gas. But because this is only a recommendation, and not a requirement, there is no harm to be done in running it on 87 (other than a possible loss of power and increase in fuel consumption).

Engine performance is often characterized by the engine operating behavior in the speed–load domain, for example, the behavior of emissions, fuel consumption, noise, mechanical and thermal loading.

My take on this is that in all domains (high temp, low temp, high load, etc etc), 91 or higher is the best option to achieve all aspects of engine performance but it doesn't mean there could be any harm to your engine or even that 91+ will make the most HP.

 

[colnago1331]

This my exact philosophy.

Mine is similar: Costco is always the first choice, with any Top Tier being my second choice. And Costco's spot at #1 has mostly to do with the fact that it's usually at least $0.30/gallon less than anywhere else.

 

[adam1991]

In fact, Kia does say - in the owner's manual - that using fuel with a lower octane rating than 91 "could result in loss of engine power and increase in fuel consumption," and that Kia recommends using 91 for "optimal engine performance." Moreover, my manual makes no mention of 87 octane . . . only 91 octane. What this tells me is that the engine was designed to run on 91 gas.

So 91 is the target, then--the ceiling.

Higher octane would do nothing, otherwise they'd have said so.

I'm curious--what does the sticker in the gas door say? Does it simply say "use 91", or does talk at all to 87?