E 10 : energy vs octane

[bonnie john]

just been reading that E10 is "better" for my (LS1 powered) car than regular unleaded 92 (RON)

is this just the knock resistance?

coz i didn't think that ethanol blends had the btu's that straight petrol has, which i take to mean my mpg will suffer

the ute is a 2003 aussie GM 6 speed manual driven VERY sedately with mixed town and country use, totally stock with about 50,000 miles racked up so far

 

[Shannow]

As the energy content drops, the fuel economy and power drops.
As the octane rises, fuel economy and power increase, but only if the engine can use it.

E10 in your engine may be marginally better, or worse, depending on how the engine uses it.

Try 3-4 tanks of regular, 3-4 tanks of 95RON (Caltex has a 95), then 3-4 tanks of E10.

 

[TwoWheelRider]

Ethanol raises octane becuase it does not ignite as readily as more traditional components of gasoline, but the resulting formulation is adjusted to have the same 87, 89, 92, etc. octane value as pre ethanol formulations.

Etahnol's energy content is lower though so you end up with less power in the end.

So E10 = same octane, less power + increased chance of corrosion issues

 

[wapacz]

now e85 has a higher octane than most pump gas. The problem is that the only easy way to get a car that can run both and get close to the same mileage requires a turbo to increase the compression ratio when e 85 is used.