[Z06] 93vs91 octane gas
Race Director
Joined: Nov 2000
Posts: 17,103
Likes: 39
From: stop the fun suckers
I think the BCM advances the timing until the knock modules sense some ping/detonation and then back off the timing a little.. more octane usually means more resistance to knock.. hence I think you get a tad more power... not enough to worry about probably..
Pro
Joined: Aug 2001
Posts: 627
Likes: 0
From: MD
From the FAQ:
Also, Gasoline and octane facts.
Should help.
Engines
5.7L (LS1) V8 5.7L (LS6) V8
V8 Application: STD on Coupe, Convertible STD on Z06
Type: 5.7-liter OHV
Block Material: Cast aluminum
Displacement (cu in/cc): 350 / 5665
Bore x stroke (in/mm): 3.90 x 3.62 / 99.0 x 92.0
Cylinder head material: Cast aluminum
Valvetrain: Overhead valve, two valves per cylinder
Fuel delivery: SFI
Compression ratio: 10.1:1 10.5:1
Horsepower/kilowatts: 350 / 261 @ 5600 rpm 405 / 302 @ 6000 rpm
Torque (lb-ft/Nm) 375 / 508 @4400 (manual)
360 / 489 @4000 (automatic) 400 / 542 @ 4800 rpm
Recommended Fuel 91 Octane
Maximum Engine Speed 6000 rpm 6500 rpm
Emission control system: Catalytic converter AIR
EPA Estimated Fuel economy (mpg city/hwy/comb) 19/28/23 (manual transmission on coupe and convertible
18/25/21 (automatic transmission on coupe and convertible) 19/28/23 (manual transmission Z06)
5.7L (LS1) V8 5.7L (LS6) V8
V8 Application: STD on Coupe, Convertible STD on Z06
Type: 5.7-liter OHV
Block Material: Cast aluminum
Displacement (cu in/cc): 350 / 5665
Bore x stroke (in/mm): 3.90 x 3.62 / 99.0 x 92.0
Cylinder head material: Cast aluminum
Valvetrain: Overhead valve, two valves per cylinder
Fuel delivery: SFI
Compression ratio: 10.1:1 10.5:1
Horsepower/kilowatts: 350 / 261 @ 5600 rpm 405 / 302 @ 6000 rpm
Torque (lb-ft/Nm) 375 / 508 @4400 (manual)
360 / 489 @4000 (automatic) 400 / 542 @ 4800 rpm
Recommended Fuel 91 Octane
Maximum Engine Speed 6000 rpm 6500 rpm
Emission control system: Catalytic converter AIR
EPA Estimated Fuel economy (mpg city/hwy/comb) 19/28/23 (manual transmission on coupe and convertible
18/25/21 (automatic transmission on coupe and convertible) 19/28/23 (manual transmission Z06)
Should help.
Burning Brakes
Joined: Aug 2007
Posts: 880
Likes: 0
From: Bath PA
If everyone read this the gas companies would sell a whole lot less "premium" fuel. It's one thing to put 93 instead of 91 in a car with 10.5:1 compression, but the number of sheep who put it in their Cavalier and don't need it is scary. And just try explaining it to them.
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
yeah, agree with you. I have tried repeatedly to tell some people they don't need premium, even oil companies and car companies say use only what needed to keep car from pinging (detonation) but people still think "more is better" like many do in everything in life
Melting Slicks
Joined: Dec 2003
Posts: 2,334
Likes: 11
From: las vegas nv.
Racer
Joined: Feb 2007
Posts: 251
Likes: 0
From: Springdale AR
Yes yes, some gas stations around where I live used to have a "premium for the price of regular!" sale for one day of the week. The lines were huge! One gas station had to hire security just to help with traffic control. And oooooh people would get mad if you cut in front of them. For me at the time, I needed premium anyway ('96 Impala SS heavily tuned). But to see these people with their cars in the lines was truly a sight to behold. Old beat up Cavaliers, early 80's Hondas, even newer economy cars with stock engines... they were all there. And the people were usually Arkansas' finest, the kind of people you'd see on Jerry Springer. They were all hell bent on the notion that they're get better gas mileage and a lot more horsepower from the 91 octane, and you could NOT convince them otherwise.
With regards to the "Gasoline and octane facts" FAQ, I've always been curious why some states like Colorado have lower octane at the pump. Their "regular" is 85 instead of the 87 I see in most areas. And the FAQ says that higher octane is needed in higher altitudes. I'm so curious.
With regards to the "Gasoline and octane facts" FAQ, I've always been curious why some states like Colorado have lower octane at the pump. Their "regular" is 85 instead of the 87 I see in most areas. And the FAQ says that higher octane is needed in higher altitudes. I'm so curious.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Le Mans Master
Joined: Jul 2009
Posts: 9,526
Likes: 12
From: Los Angeles California
If everyone read this the gas companies would sell a whole lot less "premium" fuel. It's one thing to put 93 instead of 91 in a car with 10.5:1 compression, but the number of sheep who put it in their Cavalier and don't need it is scary. And just try explaining it to them.
Race Director
Joined: Dec 2006
Posts: 12,356
Likes: 2,893
From: Fort Worth, Texas
Yes yes, some gas stations around where I live used to have a "premium for the price of regular!" sale for one day of the week. The lines were huge! One gas station had to hire security just to help with traffic control. And oooooh people would get mad if you cut in front of them. For me at the time, I needed premium anyway ('96 Impala SS heavily tuned). But to see these people with their cars in the lines was truly a sight to behold. Old beat up Cavaliers, early 80's Hondas, even newer economy cars with stock engines... they were all there. And the people were usually Arkansas' finest, the kind of people you'd see on Jerry Springer. They were all hell bent on the notion that they're get better gas mileage and a lot more horsepower from the 91 octane, and you could NOT convince them otherwise.
With regards to the "Gasoline and octane facts" FAQ, I've always been curious why some states like Colorado have lower octane at the pump. Their "regular" is 85 instead of the 87 I see in most areas. And the FAQ says that higher octane is needed in higher altitudes. I'm so curious.
With regards to the "Gasoline and octane facts" FAQ, I've always been curious why some states like Colorado have lower octane at the pump. Their "regular" is 85 instead of the 87 I see in most areas. And the FAQ says that higher octane is needed in higher altitudes. I'm so curious.
Burning Brakes
Joined: Jun 2004
Posts: 1,240
Likes: 2
From: Cedar Rapids Iowa
The ECM automatically compensates for different air pressure. Less fuel will be injected at higher altitudes. One of the huge advantages over carburetors.
Le Mans Master
Joined: Dec 2006
Posts: 7,251
Likes: 16
From: Phoenix Arizona
