Mid-Grade in LS1s?
05-21-2009, 05:39 PM
#22
Here's an interesting chart showing what cars recommend or require you to run premium in them. The number of premium gasoline cars is steadily increasing too.
http://www.usatoday.com/money/autos/...mium-gas_N.htm
http://www.usatoday.com/money/autos/...mium-gas_N.htm
05-21-2009, 06:02 PM
#23
Not true.
Your gas mileage gets worse as it goes up in octane.. Octane is a rating of combustion, the higher, the harder to ignite.. So more spark is needed for a more complete combustion. If you were to put a lower octane, more easily combustible fuel in it, then it burns more completely and gives better gas mileage.
Your gas mileage gets worse as it goes up in octane.. Octane is a rating of combustion, the higher, the harder to ignite.. So more spark is needed for a more complete combustion. If you were to put a lower octane, more easily combustible fuel in it, then it burns more completely and gives better gas mileage.
But as far as practical application in these cars look at it this way:
The higher the octane the harder it is to PREDETONATE. Higher octane contains no more energy but resists predetonation better than lower octane. This allows the car to run optimal timing without going into KR for more power AND efficiency
However, if by running lower octane fuel your car begins to predetonate it will pull timing causing inefficincy, loss of power and ultimately engine damage.
I think we kinda mean same thing just saying it differently.....
BTW the whole theory with the reverse flow heads in the LT cars was to have the water go through the heads first where it could cool the heads better so they could run MORE timing WITHOUT predetonation.
And yes I know there is a sweet spot and the MOST timing you CAN run is not always the best for power and efficiency.
