[Shop-talk] Premium for Turbos

[BJNoSHOV8]

My current car is supposed to get better mileage with premium.  I've 
checked my mileage for 10k miles.  Most of this was with regular octane 
but I did put in high octane for about 7 tankfulls and I could not prove 
from my statistics that I got better mileage with premium.  I did expect 
it to be a little better, maybe not equal to the increase in cost.  
Granted it is not possible the way I drive to do a real scientific long 
term test, so I'm not drawing any conclusions based on my own experience.

>> But the cost difference between $2.69 a gallon, and $3.00 a gallon 
>> (current gas prices by me,) if you drive 16k miles in a year 
>> and you get 
>> 25 MPG, then it will only cost you $198.4 dollars A YEAR more for the 
>> premium.
>>     
>
> Unless of course, using premium means you actually use less fuel for the
> same distance.  Pretty much all modern cars use a knock sensor to measure
> fuel octane, and advance the spark accordingly.  More octane means more
> advance which usually means better fuel mileage.