91 Octane ?
Thread Starter
Melting Slicks
Joined: Feb 2015
Posts: 2,122
Likes: 452
From: Syracuse-Central Square New York Winer of the all Corvette race WGI 8/23!
91 Octane ?
I just realized GM is requiring 91 octane in the LT4. Has any one under normal driving conditions use the mid grade 89? I would guess the fuel and timing management would compensate.
Turn 12!
Joined: Jan 2008
Posts: 5,976
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From: The Beach
Put in the highest quality that you can find at the pump; 91\92. You own a Z06, not a Prius. Take care of your motor and it will run like designed. If you are worried about saving a couple of bucks, you purchased the wrong car. Enjoy!
Safety Car
Joined: Jul 2001
Posts: 4,661
Likes: 67
From: Ocean Springs MS
For the LT4, it says "If equipped with the LT4 supercharged engine, use premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 91 or higher. If the octane is less than 91, damage to the engine may occur and may void the vehicle warranty."
Don't scrimp on fuel to save a buck or two.
Advanced
Joined: Jul 2009
Posts: 55
Likes: 0
Lower Octaine and cheap gas
Lower Octaine and cheap gas will harm your engine. In the old days before computers if you used less Octaine than specified it would cause engine knock which causes damage to your engine. For example I had a boat engine that mechanics changed the spark plugs and left one plug loose causing detonation and it had a knock sensor. The end result was the aluminium from the top of the piston transferred to the cast iron head causing a complete loss of compression and the motor had to be rebuilt. Cheap gas. I was running cheap gas in a 1986 corvette with fuel injection. After a while it felt like it was running on 7 cylinders. I took it to a local mech and he discovered that one injector was not opening at all. The fix Chevron gas and two bottles of Tecron in the gas tank. After that I believe in Chevron and their additives. Check a late model GMC vehicle owners manual and they recommend Top Tier Gas. Go to toptiergas.com for a list of fuel companies that now sell products with the necessary additives for modern engines. Don't scrimp on good fuel or we will see your car in the shop for a fix that's not cheap.
