Gas Grade

[ajtx00]

So I stopped at a QT in Hutto/Pflugerville, TX and they had 4 gasoline options. Anyone ever use 90 in there BW? I’ve always put 93 but I’ve never seen a gas station with more than 3 options. I’m curious to know what 90 does to the engine (I’m thinking less performance IMO).

 

[TLM]

I am not a gas expert but the 90 has no ethanol in it. The 93 probably has up to 10% of ethanol in it. Here in central WI, you can get 91 with no ethanol and 93 that has up to 10% of ethanol.

 

[piranha971]

Why would you want to do that? 91 is the minimum specified. Sure it will run it, but may be rewarding timing to keep knock under control.

 

[ajtx00]

I wouldn’t run 90 or 91 since 93 is abundant in the Austin area. For those that are in a rural area, maybe they don’t have access to 93

 

[ajtx00]

I am not a gas expert but the 90 has no ethanol in it. The 93 probably has up to 10% of ethanol in it. Here in central WI, you can get 91 with no ethanol and 93 that has up to 10% of ethanol.

Is 90 (correct, no ethanol) good or bad, verses 93 with 10% ethanol?

 

[1Evil55]

Up in da nort woods some guys prefer the non eth blend so it doesn't destroy their old equipment.

 

[USMC1911]

Use the 93. In a turbo or supercharged car like a Blackwing the ethanol helps somewhat resist detonation, the higher the ethanol content the more resistant to detonation. the more timing you can put to it. Non ethanol will have more BTUs though. The non ethanol should theoretically get better fuel economy, also.

 

[nordique14]

I have a pump nearby that dispenses non-ethanol 92. A little more than the usual stuff but I use it if the car is going to sit for a while (like in the winter)

 

[Dirkbg]

Plus the cost of 90 (pure gas) around here is the same as premium 93 (with ethanol). I buy the 90 for my lawn equipment and for my 1992 Camaro that's basically in storage that requires premium, but I don't want ethanol in a car that runs infrequently.

 

[PrimeTime]

Plus the cost of 90 (pure gas) around here is the same as premium 93 (with ethanol). I buy the 90 for my lawn equipment and for my 1992 Camaro that's basically in storage that requires premium, but I don't want ethanol in a car that runs infrequently.

What's "infrequently" as far as driving and ethanol, how to determine and how does that play into the type of gas used? IDK?

Looking to learn. Thanks.

 

[CBH]

This is an on-going debate with bikers too. I've have buddies in both camps. QT, btw, is where we gas up for rides too - for that reason.

I would be interested in some facts or evidence that one is better than the other. 90 pure gas is more expensive than 93 ethanol premium.

I'd buy 92 non-ethanol if I could. But on the fence about 90 vs 93. New cars should have fuel lines that can withstand the ethanol, so not sure it really matters.

 

[USMC1911]

What's "infrequently" as far as driving and ethanol, how to determine and how does that play into the type of gas used? IDK?

Looking to learn. Thanks.

Infrequently would be several months and is much more geared towards wet weather climates as the ethanol gas takes in moisture. For something like my lawn mower here in Oregon, I run ethanol the majority of the summer and then switch the last month or so I know I'm going to be mowing to the non-ethanol because I know it's going to possibly sit over the winter and into spring. Stuff that takes mixed gas I usually don't even mess with ethanol gas. Our cars are literally built around the use of ethanol gas. Cars from a couple of decades ago not so much.

 

[USMC1911]

This is an on-going debate with bikers too. I've have buddies in both camps. QT, btw, is where we gas up for rides too - for that reason.

I would be interested in some facts or evidence that one is better than the other. 90 pure gas is more expensive than 93 ethanol premium.

I'd buy 92 non-ethanol if I could. But on the fence about 90 vs 93. New cars should have fuel lines that can withstand the ethanol, so not sure it really matters.

One being better than the other comes down to the use case IMO. It's proven that ethanol helps resist detonation in turbocharged and supercharged cars that tend to run hot especially on the intake charge temperatures. Ethanol doesn't have as many BTUs so it takes more fuel, thus cooling the chamber and decreasing the likelihood of detonation, which in turn allows a more aggressive timing curve = more power. The trade is less fuel economy for ethanol as it takes more fuel volume to get to the same amount of BTU. It's the same reason an alcohol-powered drag motor runs at such low temperatures as you're dumping massive amounts of fuel in comparison to conventional gasoline. On my twin turbo Nova when we switched from pump 93 to E85 we went from 80 lb ejectors to 120s just to keep it from running out of fuel and the duty cycle of the injectors was still almost tapped out.

 

[mfcentex]

Yes, ethanol is bad with moisture. I had some issues with a boat after I couldn't find non-ethanol gas in the area. It was fuel pump related. That being said, modern vehicles shouldn't have an issue.

Sta-bil makes a marine version geared toward ethanol.

 

[PrimeTime]

Around here, at the pump its ID as REC 90, non ethanol. The pump pic in @ajtx00 post must be the same @ 90 N.E fuel..

Thanks for the insight.

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[piranha971]

You guys do know that people seek out ethanol because it makes a ton more power because it effectively bumps up your octane and resists detonation? People run full E85 in these cars and as long as its not in the winter and they don't let it sit it generally is ok. There are a few quirks and I certainly wouldn't do E85, but I ran E25 or so in my ATS-V and it was great. I put a gallon or two of E85 into my wife's X5 to allow me to run a preloaded JB4 map 2 without timing retard and I have done the same with our previous Explorer TT. Ethanol is great in moderation.

 

[hawk02]

I’ve long wondered why GM doesn’t offer FlexFuel capability in its high-performance models like the Camaro, Corvette, or Cadillac V-series. The modern LT-series engines thrive on high octane, and the cooling benefits of ethanol—especially in supercharged or turbocharged setups—are well documented.

I understand there are engineering and cost considerations. Supporting E85 would require larger injectors and upgraded fuel system components to accommodate the lower energy density of alcohol-based fuels. Fuel economy would likely take a hit as well.

That said, GM previously offered FlexFuel in models like the Tahoe, Yukon, and Escalade. From a marketing perspective, the ability to safely unlock an additional 40–50 horsepower with E85 seems like a worthwhile trade-off—especially in a performance segment where every bit of power counts.

Imagine the appeal of a Cadillac with over 700 horsepower and the flexibility to run on E85. I believe demand for such a configuration would be extremely strong among enthusiasts.

It would be great to see GM revisit FlexFuel as a performance feature—not just a fleet economy tool.

 

[ngoni]

I’ve long wondered why GM doesn’t offer FlexFuel capability in its high-performance models like the Camaro, Corvette, or Cadillac V-series. The modern LT-series engines thrive on high octane, and the cooling benefits of ethanol—especially in supercharged or turbocharged setups—are well documented.

I understand there are engineering and cost considerations. Supporting E85 would require larger injectors and upgraded fuel system components to accommodate the lower energy density of alcohol-based fuels. Fuel economy would likely take a hit as well.

That said, GM previously offered FlexFuel in models like the Tahoe, Yukon, and Escalade. From a marketing perspective, the ability to safely unlock an additional 40–50 horsepower with E85 seems like a worthwhile trade-off—especially in a performance segment where every bit of power counts.

Imagine the appeal of a Cadillac with over 700 horsepower and the flexibility to run on E85. I believe demand for such a configuration would be extremely strong among enthusiasts.

It would be great to see GM revisit FlexFuel as a performance feature—not just a fleet economy tool.

Unless there's a change in GM leadership they're hell-bent on getting rid of ICE no matter what the market says.

 

[USMC1911]

I’ve long wondered why GM doesn’t offer FlexFuel capability in its high-performance models like the Camaro, Corvette, or Cadillac V-series. The modern LT-series engines thrive on high octane, and the cooling benefits of ethanol—especially in supercharged or turbocharged setups—are well documented.

I understand there are engineering and cost considerations. Supporting E85 would require larger injectors and upgraded fuel system components to accommodate the lower energy density of alcohol-based fuels. Fuel economy would likely take a hit as well.

That said, GM previously offered FlexFuel in models like the Tahoe, Yukon, and Escalade. From a marketing perspective, the ability to safely unlock an additional 40–50 horsepower with E85 seems like a worthwhile trade-off—especially in a performance segment where every bit of power counts.

Imagine the appeal of a Cadillac with over 700 horsepower and the flexibility to run on E85. I believe demand for such a configuration would be extremely strong among enthusiasts.

It would be great to see GM revisit FlexFuel as a performance feature—not just a fleet economy tool.

If I had to guess it has to do with government regulation of fuel standards and emissions. I don't think its a cost deal as many of the exotics that would also benefit don't offer it. It obviously not just a GM thing.

 

[TruckeeTaurus]

Man… I just drove up the CA coast to stay at my in-law’s place for the weekend and the highest any gas stations within a couple hours offer is 91. ‍