93 octane?
Instructor
Joined: Dec 2005
Posts: 188
Likes: 5
From: Was Los Angeles, now Phoenix, Arizona
Drifting
Joined: Mar 2020
Posts: 1,570
Likes: 1,029
From: 31 hours East of Peoria, AZ
100 octane gas is often used in aviation and is leaded. Check first and don't clog your cats.
Melting Slicks
Joined: Aug 2000
Posts: 2,428
Likes: 1,199
From: Early 2020 Z51 Coupe, Original Owner, Ahwatukee Foothills, AZ
Luv's gas stations are in 41 states including Nevada and does carry both 100 unleaded octane as well as 110 leaded octane. I add to every tank 4 gallons of the Luv's 100 unleaded octane here in Phoenix to achieve the 93 Corvette recommended octane for the 11.5:1 compression LT2 engine. The consensus is running 91 octane will loose you 15-20 rwhp.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Aug 2016
Posts: 12,806
Likes: 10,224
From: Garden Valley CA
Luv's gas stations are in 41 states including Nevada and does carry both 100 unleaded octane as well as 110 leaded octane. I add to every tank 4 gallons of the Luv's 100 unleaded octane here in Phoenix to achieve the 93 Corvette recommended octane for the 11.5:1 compression LT2 engine. The consensus is running 91 octane will loose you 15-20 rwhp.
Melting Slicks
Joined: Aug 2000
Posts: 2,428
Likes: 1,199
From: Early 2020 Z51 Coupe, Original Owner, Ahwatukee Foothills, AZ
Good point. With the improved fuel and engine management systems and making just the same power as before wondering what the 2022 flywheel HP would be with 93 octane. I doubt if the 2022 engine compression ratio has been decreased from 11.5:1
Race Director
Joined: Aug 2016
Posts: 12,806
Likes: 10,224
From: Garden Valley CA
It would be interesting to compare the 2022 fuel/timing map to earlier versions to see if there are any differences. I suspect it is just that the LT2 doesn't require 93 octane to make the rated horsepower at standard conditions.
Last edited by RKCRLR; Oct 9, 2021 at 07:56 PM.
Thread Starter
Instructor
Joined: Feb 2021
Posts: 154
Likes: 138
From: Mohave Desert
E85 and 91
Thank you! I'm loving how the car feels so far, and yes, I noticed some pinging in mine the few times I've run straight 91 as well (my C7 was actually even worse, that car flat out ran like crap on 91). I'm somewhere around 5,800 miles on the C8 now and enjoying every bit of it.
Drifting
Joined: Mar 2020
Posts: 1,570
Likes: 1,029
From: 31 hours East of Peoria, AZ
@Kracka Well i found an e85 station and added the two gallons you suggested. Not as cumbersome as I thought since the e85 nozzle was on the same pump as the 91 so just did two transactions and done. Interesting to me that the e85 (100 Octane) was $1.40 cheaper that the 91... anyway, can't really tell if there's a difference yet but again, I appreciated the earlier advice.
Do not use any fuel labeled E85 or FlexFuel. Do not use gasoline with ethanol levels greater than 15% by volume. Prohibited Fuels Caution Do not use fuels with any of the following conditions; doing so may damage the vehicle and void its warranty: . For vehicles that are not FlexFuel, fuel labeled greater than 15% ethanol by volume, such as mid-level ethanol blends (16–50% ethanol), E85, or FlexFuel.
Race Director
Joined: Jan 2014
Posts: 10,709
Likes: 7,102
From: Fulshear, TX
@Kracka Well i found an e85 station and added the two gallons you suggested. Not as cumbersome as I thought since the e85 nozzle was on the same pump as the 91 so just did two transactions and done. Interesting to me that the e85 (100 Octane) was $1.40 cheaper that the 91... anyway, can't really tell if there's a difference yet but again, I appreciated the earlier advice.
All of the owner's manuals (2020 to 2022) say:
Do not use any fuel labeled E85 or FlexFuel. Do not use gasoline with ethanol levels greater than 15% by volume. Prohibited Fuels Caution Do not use fuels with any of the following conditions; doing so may damage the vehicle and void its warranty: . For vehicles that are not FlexFuel, fuel labeled greater than 15% ethanol by volume, such as mid-level ethanol blends (16–50% ethanol), E85, or FlexFuel.
Do not use any fuel labeled E85 or FlexFuel. Do not use gasoline with ethanol levels greater than 15% by volume. Prohibited Fuels Caution Do not use fuels with any of the following conditions; doing so may damage the vehicle and void its warranty: . For vehicles that are not FlexFuel, fuel labeled greater than 15% ethanol by volume, such as mid-level ethanol blends (16–50% ethanol), E85, or FlexFuel.
For note, E85 is typically 70-83% ethanol so for my calculations above I used 80% which is more typical in the summer while it'll go lower towards 70% in the winter. By regulation, it can go as low as 50% but that is not very common unless the economics are beneficial to the blender.
Last edited by Kracka; Oct 12, 2021 at 04:14 PM.
Drifting
Joined: Mar 2020
Posts: 1,570
Likes: 1,029
From: 31 hours East of Peoria, AZ
You're welcome! Glad to be of assistance.
2 gallons of E85 blended in to a tank E0 91 equals 9% ethanol, well under the approved limit. 2 gallons into E10 91 is still only 19% and will cause zero harm and well within the fuel trim tolerance. If that concerns you though, go with 1.5 gals instead for 14%.
For note, E85 is typically 70-83% ethanol so for my calculations above I used 80% which is more typical in the summer while it'll go lower towards 70% in the winter. By regulation, it can go as low as 50% but that is not very common unless the economics are beneficial to the blender.
2 gallons of E85 blended in to a tank E0 91 equals 9% ethanol, well under the approved limit. 2 gallons into E10 91 is still only 19% and will cause zero harm and well within the fuel trim tolerance. If that concerns you though, go with 1.5 gals instead for 14%.
For note, E85 is typically 70-83% ethanol so for my calculations above I used 80% which is more typical in the summer while it'll go lower towards 70% in the winter. By regulation, it can go as low as 50% but that is not very common unless the economics are beneficial to the blender.