6.2L Fuel Economy/Octane requirements
02-10-2011, 12:51 PM
#11
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Thanks for all the replys folks, definetly makes me feel better about geting one now.
In Central fairmont, I don't live there currently but thats where my dad and my Iroc-z stays at the moment =)
hey black where you at in laporte?
02-11-2011, 03:46 PM
#13
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Why is everyone else getting such bad mileage? Lead foot disease?
Guess everyones city driving is a bit different. 60-65 23/24ish 70-75 21/22ish just flying thru traffic driving liken *** up 45N 17-18.
Guess everyones city driving is a bit different. 60-65 23/24ish 70-75 21/22ish just flying thru traffic driving liken *** up 45N 17-18.
02-11-2011, 04:32 PM
#15
My DIC has always been at least .3 to .5 MPG high. Worse with any tune.
BEST I've ever gotten - hand calculated - was 17.5-ish driving from Houston to Mesquite (east of Dallas). Running 75-85 with the A/C running. At a steady 65 and NOT using cruise I can get around 20 . . .
02-11-2011, 04:55 PM
#16
Octane - forgot about that part of the OP's post . . .
The 6.2s are engineered for 91+ octane fuel (and/or E85 for the '09s and newer).
Each time that the ECM detects more than approximately 6 gallons of fuel has been added to the tank, the software is written in such a way that it utilizes the high octane spark advance tables. Once a certain amount (or severity) of knock has been detected by the ECM, it then reverts to the low octane spark tables - until the next time that 6+ gallons of fuel is added to the tank.
I have NO idea what the knock "threshold" is that forces the ECM to use the low-octane spark tables, but that's how it operates.
The "low octane" spark tables WILL adversely affect your torque, power and economy!
EDIT - one more small tidbit concerning octane - some export 6.2s (bound for the middle east, IIRC) are factory tuned for 95 octane fuel, and factory rated at 443 HP!
The 6.2s are engineered for 91+ octane fuel (and/or E85 for the '09s and newer).
Each time that the ECM detects more than approximately 6 gallons of fuel has been added to the tank, the software is written in such a way that it utilizes the high octane spark advance tables. Once a certain amount (or severity) of knock has been detected by the ECM, it then reverts to the low octane spark tables - until the next time that 6+ gallons of fuel is added to the tank.
I have NO idea what the knock "threshold" is that forces the ECM to use the low-octane spark tables, but that's how it operates.
The "low octane" spark tables WILL adversely affect your torque, power and economy!
EDIT - one more small tidbit concerning octane - some export 6.2s (bound for the middle east, IIRC) are factory tuned for 95 octane fuel, and factory rated at 443 HP!
02-11-2011, 05:43 PM
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And hey all that other info was cool to learn also, no idea that they adjusted for the octane like that.
02-11-2011, 05:53 PM
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Octane - forgot about that part of the OP's post . . .
The 6.2s are engineered for 91+ octane fuel (and/or E85 for the '09s and newer).
Each time that the ECM detects more than approximately 6 gallons of fuel has been added to the tank, the software is written in such a way that it utilizes the high octane spark advance tables. Once a certain amount (or severity) of knock has been detected by the ECM, it then reverts to the low octane spark tables - until the next time that 6+ gallons of fuel is added to the tank.
I have NO idea what the knock "threshold" is that forces the ECM to use the low-octane spark tables, but that's how it operates.
The "low octane" spark tables WILL adversely affect your torque, power and economy!
EDIT - one more small tidbit concerning octane - some export 6.2s (bound for the middle east, IIRC) are factory tuned for 95 octane fuel, and factory rated at 443 HP!
The 6.2s are engineered for 91+ octane fuel (and/or E85 for the '09s and newer).
Each time that the ECM detects more than approximately 6 gallons of fuel has been added to the tank, the software is written in such a way that it utilizes the high octane spark advance tables. Once a certain amount (or severity) of knock has been detected by the ECM, it then reverts to the low octane spark tables - until the next time that 6+ gallons of fuel is added to the tank.
I have NO idea what the knock "threshold" is that forces the ECM to use the low-octane spark tables, but that's how it operates.
The "low octane" spark tables WILL adversely affect your torque, power and economy!
EDIT - one more small tidbit concerning octane - some export 6.2s (bound for the middle east, IIRC) are factory tuned for 95 octane fuel, and factory rated at 443 HP!
02-11-2011, 05:59 PM
#20
I'm glad somebody else noticed this, hopefully the OP is still reading. While the prior two posters were correct in their statements that a vehicle tuned for regular unleaded will gain nothing from premium, they missed the fact that the L92 trucks come from the factory tuned for 91+. Because of this, the computer will pull timing if a lower octane fuel is used, and power and efficiency will suffer.