[ember1205]

Originally Posted by djctoto

Sunoco is now offering 94 Octane instead of 93 at most locations in New England. Not sure where else but easy to search here:
https://www.sunoco.com/find-a-station

If you're modded / tuned, the 94 might be useful. For stock, it's unlikely to provide any noticeable change.

My experience with the Sunoco 94 is that you pay a premium for it, too. At least in my area, it was considerably more than any other top tier station selling 93.

[Capricio]

What passes for high octane/premium is based on your regional distributor's elevation. I have seen pumps around Denver with 85 regular and 89 premium. Where I live is around 4600 feet and its very hard to find anything above 91 at a regular pump, even at higher end stations like Chevron. Closer to sea level, you can usually find 93 more readily.

[speedyink1]

I exclusively use Chevron 94 (Top Tier, and has Techron). I don't have an option to have 10% Ethanol, 94 is only offered as 0%. I'd have to step down to 91 if I wanted 10% Ethanol, which I'd rather not do. Or go to Shell which has 93 with 10% Ethanol, but I like Chevron since it has Techron cleaning properties to keep the carbon deposits down.


Also, cost here for 0% E is a non issue. The price difference between 94 and 91 is tiny. The biggest jump in price is when you go above basic 87 here.

[ctrlz]

Originally Posted by DamonZ28

Wow, great info here. I thought that Premium 91 was good enough, and I've been running it for a couple of years. I will switch back to 93 Top Tier (Mobil/Exxon in my area) immediately!

91 and 93 are pretty close.
Driving on 91, you would need to see if your ECM is retarding timing compared to 93. This will be dependent on driving style. For everyday driving, I suspect 91 would be just fine.
The knock-resistance of higher octane fuels is like insurance in high engine load situations.
based on availability, I have been forced to use fuels with octane below manufacturers' recommended minimum. In those situations I just avoid jamming on the throttle.
I don't think I would go below 89 for the LT1.

I assure you there are 100,000's of people right now who are buying lower octane fuels for their luxury and sports cars based on rising prices at the pump. This always happens. Not that any of them understand the implications.