What's been your experience with gas mileage (not that this is the primary concern of performance tuners) after disabling spool mode? When it's warm outside I'm getting around 21 to 22 mpg with maybe 75% highway and 25% city driving in a week. I'm just curious how bad the gas mileage tanks with richening up the fuel mixture.
'10 BMW 335i xDrive. BMS Dual Cone Intakes. Cobb Stage 1 Aggressive.