how badly does turbo or super charging kill your gas mileage in a e36 m3? im thinking about spending 300 bucks on a 100 dryshot no2 but also considering saving my money for a super or turbo later on

wrong section

http://forums.bimmerforums.com/forum/forumdisplay.php?f=150

thats the section ull get answers. this ones just to sell things and request things.

Some claim it improves gas milage...that is, when just cruising around.:)

Gas milage will be more dependant on the tune.

I think its the Turbo which is often touted as improving gas mileage a little. Has to do with the breaking up of the exhaust pulses and actually lessening the backflow resistance.

Superchargers, on the other hand, provide a constant and not inconsequential drag on the engine .. And they do so at all speeds and rpm levels. So, in order to overcome the resistance they provide, it takes gasoline. With my Vortech, I get an avg of 15 mpg in all city driving, and about 22 mpg on all parkway nonstop driving. Overall, that calculates to something like a 2mpg loss or something like that.

With turbocharging, you won't lose any mileage as the engine behaves almost the same when it's not under much load. Some claim to get better mileage too.

With a supercharger, you always have parasitic drag so you will get a bit worse mileage.

The biggest factor (in any car) is how you drive. If you floor it, you get bad mileage no matter what.