GM Truck Club Forum banner

2021 Silverado 6.2l - regular gas?

604 Views 6 Replies 3 Participants Last post by  RayVoy
I've searched the site, and the threads found discussing premium vs regular in the Chevy 6.2l V8 are quite old.

The specs I've found online say this engine has a compression ratio of 11.5:1, which in the "old days" would mean premium fuel.

My owner's manual says:

Recommended Fuel (6.2L V8 Engine)
Premium unleaded gasoline meeting ASTM specification D4814 with a posted octane
rating of 93 — (R+M)/2 — is highly recommended for best performance and fuel
economy. Unleaded gasoline with an octane rated as low as 87 can be used. Using
unleaded gasoline rated below 93 octane, however, will lead to reduced acceleration
and fuel economy
(underlining is mine)

I've experimented with regular gas for a recent trip with my truck, and did not notice any issues.

I assume the engine control is adjusting the timing.

I didn't time any 93 vs 87 acceleration numbers, but I noticed no (obvious) power reduction and the gas mileage (calculated by the truck - I did not verify) did not materially change (it is still in the vicinity of 20 mpg for highway cruising @ 65 mph).

Does anyone else here run regular gas with this engine?
1 - 3 of 7 Posts
Per GM................
... Only use the octane-rated fuel recommended as specified in the vehicle’s Owner’s Manual.
Please see my quote from the owner's manual for my truck in my OP.

Here it is again:

"Unleaded gasoline with an octane rated as low as 87 can be used."

My question wasn't about what was permitted by GM - I already knew 87 octane was permitted; I was wondering if using 93 octane had any real measurable benefits (other than making my wallet thinner).
What I posted came right from GM so take it up with them if you disagree. Your owners manual says premium fuel is "highly recommended". Note, engine damage from not using the recommended octane could be subject for warranty denial.

Here► Optimizing Fuel Economy with Top Tier Gasoline
They won't deny a warranty claim for using a fuel they say is OK to use.

Again, my question is not whether or not I have GM's blessing (my owner's manual says I do), but whether using premium fuel make a measurable difference in fuel economy or power.
1 - 3 of 7 Posts