[warp ten]

I tend to agree with Meyerweb that for these cars it is probably a good idea to use 91 or 93 even though it currently costs more to do so. I have the great misfortune of owning two BMWs and my Z06, so every car I own requires 91 or better. I mostly get my gas at Costco, where the only choices are 87 and 93, so I am in for 93. At about $5.40 a gallon last time I filled up. Probably higher now. Oh well, what goes up must come down. I hope. --Bob

 

[C7 STRAY]

I tend to agree with Meyerweb that for these cars it is probably a good idea to use 91 or 93 even though it currently costs more to do so. I have the great misfortune of owning two BMWs and my Z06, so every car I own requires 91 or better. I mostly get my gas at Costco, where the only choices are 87 and 93, so I am in for 93. At about $5.40 a gallon last time I filled up. Probably higher now. Oh well, what goes up must come down. I hope. --Bob

 

[C7 STRAY]

Like warp ten, I also own 2 BMW's and a 2014 Stingray. The first BMW is a 2012 X3. When confronted with their hi-octane requirement I balked, decided I'd try 87 octane unleaded regular, and monitor the results. Zero issues, no noticeable loss of acceleration or fuel mileage, no mechanical problems, still going strong 10 years later. Bought the C7 in 2014, haven't fed it anything but 91 non-oxygenated premium, and won't screw with it, as the non-oxy premium is readily available in northern WI, and I run very few miles annually on it, so not really worth experimenting. Latest acquisition is a 2019 BMW X7, a hulk of an SUV, very fast and powerful, and as usual, a 91+ octane requirement. It now has nearly 50,000 miles on it, goes from WI to CA and back annually, averages over 25 mpg on those trips over the Rockies and Sierras, often over 27 mpg on the flatlands, and has NEVER had anything but 87 octane unleaded 10% ethanol fuel. This probably means nothing, only anecdotal info on two vehicles, as a GM Corvette is not a BMW, and their engineering philosophies probably differ greatly. But Deter (my mythical BMW design engineer that I blame for all of their idiosyncrasies) and Tag might secretly both agree that their vehicles' sophisticated computer systems can adapt to any reasonable octane fuel, albeit with a commensurate loss of performance and/or mileage, but without damage to the engine. Just my slightly-educated opinion.

 

[bluenitec7]

Why do you want to use 87 octane??
Cost savings isn’t going to be that great.

 

[C7 STRAY]

Why do you want to use 87 octane??
Cost savings isn’t going to be that great.

On any individual trip, agreed. As I said, my C7 is low annual mileage, so not worth trying to scrimp. But on an everyday driver, over 50 or 100,000 miles it adds up to thousands of $. Still not worth it if you incur engine damage or a noticeable loss of performance or mileage. In my case with two BMW's neither negative has surfaced, so if things don't change (and after this much time and miles I doubt it will) I'm money ahead. Not trying to preach low octane, or even suggest anyone else try it, just citing two examples over years and miles where it doesn't really seem to matter.

 

[bjniceguy]

i totally agree on staying with premium, but at different altitudes the octane available changes. When you get above 1,000 feet, I have seldom seen premium higher than 91. A lot of the midwestern states Costco have alcohol in their premium so keep that in mind. Not sure where all you are going, but you will see a $1.00 a gallon Raise at the California border. I just finished a similar 4,800 mile loop from Iowa. I was full when left Reno Nevada going into California. Drove from north of Frisco down the coast all the way to San Diego and back into Yuma Arizona. Was driving a Pickup getting 27MPG and I only had to buy 20 gallons of California fuel (figure extra $20 LOL).

 

[Fleet]

A Google search resulted in " LT2 495 horsepower 6.2-liter engine with just 4,809 miles that's going for a cool $19,999.99, with another $595 for shipping". I'll stick with Premium, thank you very much!

 

[anapurano]

That's not correct. Costco has their own additive mix that is added to the fuel AT THE STATION, not at the terminal. And all Costo gas is Top Tier.

Thank you for sharing. I wouldn't run it in mine.

 

[meyerweb]

Thank you for sharing. I wouldn't run it in mine.

I've run it in all my cars, including Corvettes, for 5 or 6 years. Not a hint of a problem. Enjoy wasting money.

 

[meyerweb]

A lot of the midwestern states Costco have alcohol in their premium so keep that in mind.

In most urban / suburban areas in the US you'll get alcohol in your gas no matter where you buy, per EPA clean air mandates.

If the pump says up to 10% alcohol, that's usually the regular, and Premium will have less.

Every car made in the last 30 or 40 years will have no issues with 10% alcohol in the fuel. It won't hurt your car in any way.

 

[bob67327]

Friends, for whatever it's worth, ever since visiting with people in Oregon State's Engineering School (where I did geophysics long ago), I've run the least expensive gasoline I could find in every car I've owned. For nearly 60 years.

Besides the 2014 C7 M7 we bought new and have driven over 104,000 miles, this includes (among other cars) two Corvairs, a C2 we had for over 4 years and nearly 100,000 miles, a Saab Turbo, two Jeeps, a BMW M3, and two Porsches. We've driven Honda sedans to Alaska twice (all the way up the long gravel roads well past the Arctic Circle nearly to the Arctic Ocean) and twice to Labrador and Newfoundland (which is not nearly as far north as many people imagine).

Maybe we've just been lucky?

 

[jsvette]

bob67327, I am not sure luck has much to do with it. The issue isn't whether our (or other cars) can run less than the recommended octane fuel- all modern engines have CPUs that adjust for the fuel within reason, but whether putting in a lower octane fuel truly saves you money. Much of the research I've read indicates that your mpg goes down when you run octane rated lower than what your engine was tuned for.

It is a personal decision. Your approach has clearly worked for you and the cars you have owned.

 

[bob67327]

Thanks so much, Jsvette! You have correctly identified a foolish old man's serious error of omission: I failed to say that the "least expensive gasoline" purchased was always for the octane required. That means we're now buying gas costing at least 50 cents / gallon more than the "least expensive"! Sorry to all for that serious mistake.

I know that what Jsvette wrote is definitely true - using lower octane fuel in an engine designed for higher octane costs efficiency. Even if "it works fine". Not worth it for people like us, Stingray Forums readers, as Jsvette implied.

My apologies again, friends - I hope that my note does not mislead anybody! Most especially since the title of this thread is:
"Use Regular(87) for long trip ?"
My opinion: NO, PLEASE DON'T DO THAT!
Best regards, bob
PS - here's a photo of our IP after we got home from our last trip; couldn't have achieved 36.4 on low octane fuel. We also used 4-cyl mode when cruising under light load. This is the highest overall MPG ever for us, motivated by the extra-expensive fuel these days. We paid between $4.20 / gal (Kansas City, Costco, May 21) and $5.50 / gal (Rochester, Indiana, June 5). One place we bought gas the price went up 40 cents / gal overnight!

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[Racer57]

I suspect everyone is right. Average driving on interstate sticking to 70mph won't have any engine issues but mileage will be affected if using less than midgrade. Thanks for responses. Btw, Bob67327 I'm glad to see you actually drive your car.

 

[anapurano]

I've run it in all my cars, including Corvettes, for 5 or 6 years. Not a hint of a problem. Enjoy wasting money.

Of course I enjoy wasting money. I bought a Corvette.