[JayhawkNation]

Just traded in my ‘16 SS for a ‘19 SS last weekend and noticed in the new owners manual that the recommended fuel octane was changed to 93 from 91 when I bought my ‘16. Looking online at an ‘18 owners manual it appears to be 93 as well.
Anyone have any speculation why the change was made, and how SOL am I if 93 is hard to come by in my area?

[nicktechla]

You'll be fine with 91

[JT58]

93 will provide the best possible performance. 91 should be fine.

[iPODFAN11]

The 91 to 93 octane change was made on all 6.2 applications for 2017.

[TJay74]

Correct, it has been 93 since the 17 6.2 vehicles. 91 will be fine, 91 with E10 will be better. 93 and or 93 with E10 would be the best if they are around.

Most of the year you wont have any problems, during the summer months when the IAT values tend to be higher is when the 6.2's start to still see knock while on 91.

[crosive]

93 is not available everywhere.

[Juiced1]

It'll live on 91 but it will knock. As a tuner its a real shock to see how sensitive these knock sensors are set on the LT motors. If you're stuck with 91 I'd look to see if anyone has E85 by you. If that's the case you can at least get a flex fuel conversion.

[TRZ06]

Originally Posted by Juiced1

It'll live on 91 but it will knock. As a tuner its a real shock to see how sensitive these knock sensors are set on the LT motors. If you're stuck with 91 I'd look to see if anyone has E85 by you. If that's the case you can at least get a flex fuel conversion.

GM has always done this as far back as I can remember. My first high performance GM car was a 00' Hardtop Corvette and then the 01' Z06. The LS motors did the same thing.

If becomes VERY apparent that this happens when you have an aftermarket exhaust and you can hear the tonality and pitch change all the time.

BTW, thank you for the awesome price and service on my Corsa system I got from you guys a few weeks ago.

[soloknight6]

yea, I live in CA, so 91 is the only fuel available. When I was out of state over the summer my car was a happy camper on 93 octane. Didnt feel a power difference, but my exhaust tips sure were cleaner, and the car seemed to idle a lot smoother.

Any one have any experience with mixing fuel concentrates with 91 pump gas to up the octane?

[drperry]

Don't seem to notice a big difference between 91 shell, and 94 Petro.... Those are my only options, other than Husky... And every other vehicle I've owned has been horrible with Husky fuel, lol

Sent from my SM-G930W8 using Tapatalk

[ScaryFatKidGT]

find93.com

[TJay74]

Originally Posted by soloknight6

yea, I live in CA, so 91 is the only fuel available. When I was out of state over the summer my car was a happy camper on 93 octane. Didnt feel a power difference, but my exhaust tips sure were cleaner, and the car seemed to idle a lot smoother.

Any one have any experience with mixing fuel concentrates with 91 pump gas to up the octane?

Do you have E85 near you? If so I would add 2-3 gallons of E85 to keep the 91 around E10-E15. This will give you the detonation prevention. I ran full E85 up until I went the Procharger route, I still run E10-E20 while being supercharged.

[SnakeEyeSS]

Originally Posted by TJay74

, 91 with E10 will be better. 93 and or 93 with E10 would be the best if they are around.

Most of the year you wont have any problems, during the summer months when the IAT values tend to be higher is when the 6.2's start to still see knock while on 91.

Isn't the octane rating formulated with E10 in there? Pretty sure they don't mix 91 and 93 and then throw the E10 in.

A lot of Walmarts carry Lucas octane booster for $8 a bottle, as does Amazon, and it's a legitimate booster. A bottle will take a Camaro to about 93 from 91.

http://web.archive.org/web/201002140...ers_lucas.html


Reviewer says;

100:1 ratio takes 93 octane to 96.6



Then says one bottle(which is 15oz) is enough to take 10 gallons of 93 to 96.6.



I guess he meant to say "at least"? Because 15 oz in 1280 oz is not 100:1. I was just trying to figure how much I needed to get 19 gallons from 91 to 93.)





Anyway, to take 19 gallons from 91 to 93 it sounds like a 15 oz bottle will about do it. 1.28 ounces per gallon to raise 3.6 octane according to the test, so 24.32 oz to make 19 gallons 94.6~, if I use half that it will be 92.8 gallons from 12.16 oz., a whole bottle is 15. So I should be good with a bottle. Only need 13.3 oz to raise 19 gallons two numbers. I think

[TJay74]

The shop that did my supercharger install swears by 93 E10 for their builds. My understanding is the E10 they add to the 91 doesnt reduce the amount of gas used to make 91, it is in addition to the 91 octane the gas is already rated at.

Also it has been proven many times, those octane booster products in a bottle dont work well at all, much less not to the amount they suggest. If the bottle says it will raise the octane "1 point" that doesnt mean it takes 91 octane to 92 octane. It will raise 91 octane to 91.1 octane.

There is 1 brand of octane booster most of the high HP guys use in our parts, but that stuff isnt cheap at all per bottle.