alanaudi

I recently sent this email to APR (ECMS program):

Do you have an engine program for lower turbo pressure on the S4? I drove a 91 200TQ from NH to MD and got 27mpg only to find out that the wastegate freq valve was bad causing under boost. I thought it would be a great idea for long highway trips. Thoughts?

Any comments/thoughts?

Nogaro

When I had a chip I didn't see any MPG drop. Not sure if its even worth it.

donp

Except that at steady speed you're not using boost anyway. Boost is only under acceleration.

alanaudi

I wonder if lower boost raises MPG though...

alanaudi

so, it should raise MPG.

Ira B

You can accelerate gently (not too much throttle, slowly applied) and use little or no boost. A low boost option in a chip is about the same as a block under the gas pedal. Just take it easy and you won't use much boost or much gas.

alanaudi

When I posted my MPG from the 200TQ trip, someone replied that there must be something wrong with the boost because my mileage was so good. I realize *if* I drive like there's a block under my gas pedal I'll make better gas mileage. I wonder if a lower boost car will make better gas mileage on a long trip versus just "being careful" with your right foot.

Nogaro

maybe the chips just run the engine a bit more on the lean side, so more power but no increase in MPG.

PhoenixGTS

actually ahs to make power to push through. I do not know how fast that is (any help from someone with a boost guage?), but I bet it is around 80 mph or more. So cruising at 70-75, the maximum boost that your ECU might call for has no effect on your gas mileage.

alanaudi

It's not 100% cruising at constant velocity... passing, etc. completed under boost