What octane gas do you use?
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
This one always gets strong reactions
E-T, who was involved in designing the C5, posted many a long thread about why its bad to use low octane gas in our high compresison engine. 91 octane is fine bug I think thats the lowest you should go on a regular basis.
The engine does indeed have a knock sensor that retards the ignition when it detects pre ignition. The problem is that this is a reactive function so, by definition, the pre ignition has already occurred. Even if the damage is minor it could still cause damage. Not worth the risk for .10c a gallon IMHO. Also, if the igintion is being retarded the performance and economy is suffering
Overall, use good gas if you can get it. I use 95 octane (RON) here equivalent to US 91 octane only because premium is harder to find. I use 98 octane (RON) (equivalent to US 93 octane if I can get it. And BTW, 98 is £1.00 a litre ($7.50+ a gallon).
E-T, who was involved in designing the C5, posted many a long thread about why its bad to use low octane gas in our high compresison engine. 91 octane is fine bug I think thats the lowest you should go on a regular basis.
The engine does indeed have a knock sensor that retards the ignition when it detects pre ignition. The problem is that this is a reactive function so, by definition, the pre ignition has already occurred. Even if the damage is minor it could still cause damage. Not worth the risk for .10c a gallon IMHO. Also, if the igintion is being retarded the performance and economy is suffering
Overall, use good gas if you can get it. I use 95 octane (RON) here equivalent to US 91 octane only because premium is harder to find. I use 98 octane (RON) (equivalent to US 93 octane if I can get it. And BTW, 98 is £1.00 a litre ($7.50+ a gallon).
Last edited by DeeGee; Jul 8, 2007 at 04:12 PM.
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
91 Octane here ! It's whats available!
DO NOT USE 87 or any inferior fuel in your Vette.
You'll do damage and you wont even hear it! Do a search on this and you'll see a write up about using low octane fuel in HIGH compression motors and what it does.
It will detonate (Fuel) because we have high compression and it's burn rate is not good enough!
Thanks,Matt
DO NOT USE 87 or any inferior fuel in your Vette.
You'll do damage and you wont even hear it! Do a search on this and you'll see a write up about using low octane fuel in HIGH compression motors and what it does.
It will detonate (Fuel) because we have high compression and it's burn rate is not good enough!
Thanks,Matt
Racer
Joined: Jun 2006
Posts: 356
Likes: 0
From: Hershey PA
93 octane...and, now I found a "top tier gas" in Shell. I'll be using their highest octane. Don't have to fill 'er up. It's a mental thing with me. I get to half a tank and put in 25 to 30 bucks worth. But, then I don't drive it a lot. Just my .02 worth.
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Racer
Joined: Feb 2004
Posts: 471
Likes: 0
From: Boston MA
Yes the price of gas might rise making that couple of bucks a little more, but most vette owners love their car enough to feed it at least 93. Its just part of being a corvette owner.
Just my $0.02, but I wouldn't think of putting less then 93 in my vette.
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
