Recommended Fuel Myths (All Engines)

[TOMS1SS]

Alright, all this BS I've been seeing with a lot of myths on this forum about what fuels to use. The one that gets me is saying 93 Octane is required for the LS3 and L99. I've seen lots of people ask the same questions about Octane over and over again when the answers are contained in the last place people think to look; the manual. Don't worry LTT people the manual has you covered also. Here it is word for word from the manual itself section 8-44 Recommended Fuel:

If the vehicle has the 3.6L V6 engine (VIN Code V), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when driving. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service.

If the vehilce has the 6.2L V8 engine (VIN Code W) or the 6.2L V8 engine (VIN Code J), use premium unleaded gasoline with a posted octane rating of 91 or higher. For best performance, use premium unleaded gasoline with a posted octane rating of 93. You can also use us regular unleaded gasoline rated at 87 octane or higher, but the vehicle's acceleration could be slightly reduced, and a slight audible knocking noise, commonly referred to as spark knock, might be heard. If the octane rating is less than 87 a heavy knocking noise might be heard when driving. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine. If heavy knocking is heard when using a gasoline rated at 87 octane or higher, the engine needs service.

- First lets clear something up about 93 octane. While yes you'll get slightly better performance in your L99/LS3 it is likely a minimal benefit and probably a waste of money unless your going to racing or something to that effect. The spec for the L99/LS3 is clear as day 91 octane. It drives me nuts when I see people on this forum say otherwise especially when the difference per gallon between 91 and 93 octane can be .30 cents plus on the gallon.

As for the part about 87 octane being used in the LS3/L99 the engine computer retards the spark to compensate for the lower grade fuel. Commonly people here on Camaro5 complain that their car has reduced performance when the accidentally put 87 octane in and go back to 91 on the next tank. This is because the computer has not reset for the 91 octane and remedy I've seen for resetting the computer would be pulling fuses or unplugging the battery.

For the LTT guys sometimes I see stuff about using 89 or 91 octane in your cars. While it doesn't say anything about using a higher octane, why would you dump a more expensive fuel into your car when you'll get factory performance at 87?

[CamaroKid300]

This is nice to have this all in one post. Thanks.

However, I sense some flaming in your future.

[TOMS1SS]

Originally Posted by CamaroKid300

This is nice to have this all in one post. Thanks.

However, I sense some flaming in your future.

So do I. Personally all I really take issue with people saying that 93 octane is a requirement for the LS3/L99 when people ask (who honestly don't know) what fuel to use. If some wants to use 93 octane because they want to, I don't have a problem with that by any means its just not the required fuel.

[armysig]

Oyi....You might want to do some research on why Arizona has 91 octane fuel. I know the answer, but I want you to look it up. You'll get more out learning about it and why we have it here vs the east coast, south and some northern states.

[irocnroll]

Originally Posted by TOMS1SS

So do I. Personally all I really take issue with people saying that 93 octane is a requirement for the LS3/L99 when people ask (who honestly don't know) what fuel to use. If some wants to use 93 octane because they want to, I don't have a problem with that by any means its just not the required fuel.

I totally agree with your post, but as said above this will turn into flame war.

[CamaroFemme]

It's in the manual that at least 91 needs to be put in the V8 or it WILL go into the lower performance table, and you have to do a fuse pull to get it to reset. I can verify all this from personal experience from when someone accidentally put 87 in my tank.

Edit: I've actually never seen someone say 93 was a requirement.

[BenningJ]

I use the 89 octane in my LLT because it is actually 10 cents cheaper here in Iowa. Of course, it has 10% ethanol blend. I have used since day one without any issues.

[CamaroKid300]

Originally Posted by BenningJ

I use the 89 octane in my LLT because it is actually 10 cents cheaper here in Iowa. Of course, it has 10% ethanol blend. I have used since day one without any issues.

89 is cheaper than 87?

Wut?

[TOMS1SS]

Originally Posted by CamaroFemme

It's in the manual that at least 91 needs to be put in the V8 or it WILL go into the lower performance table, and you have to do a fuse pull to get it to reset. I can verify all this from personal experience from when someone accidentally put 87 in my tank.

True that is what it say, the battery one came from Fbodfather so who am I to say that won't work also?

[TOMS1SS]

Originally Posted by CamaroKid300

89 is cheaper than 87?

Wut?

The more ethanol in the blend the more money at the pump.

[SlingShot]

In the past two years, I don't recall very many people saying 93 was required. Also it has been proven by the V6 guys, there is a slight performance gain using premium fuel although it may not be cost effective.

[UT-Engineer]

Originally Posted by SlingShot

In the past two years, I don't recall very many people saying 93 was required. Also it has been proven by the V6 guys, there is a slight performance gain using premium fuel although it may not be cost effective.

i stick with 87 for my V6 but there is a difference when using 91/93... i just dont think its worth the cost.

[BATMANs]

I run 91 octance california gas from COSTCO in both my blown cars (see below). No issues or blown engines.

[Supercharged SS]

Who buys an SS and then wants less performance out of it? If I wanted less than what I bought I would have bought the V6.