No one has touched on this yet, but odds are with abigger turbo you may have a more aggressive tune. This might have your car running quite a bit leaner then it did stock, which would also save gas.

 

Well I can only add my experiences but on stock turbo, HKS RS, and base map flash I was getting 28mpg but that is me being in vacum most of the time. Now with the mods if I drive out of vacum I get about 30mpg. Remember you fuel pressure regulator is 1:1 the more boost you push the more fuel you have to push out of the tank. Boost for me Monday -Friday is only used to merge on the highway and even then I have my EBC set for 1bar. I may hit 5-10psi if I'm merging from a dead stop. But 90% I never have to use boost to get on the highway. Everyone try accelerating without boost for a 1 tank you will see your MPG's go up

 

someone should do this. that would be cool to see what this car is capable of

 

People seriously accelerate in boost? When I drive my car, I'm normally accelerating around -5 vacuum and cruising -15 to -17 vacuum. I will never go into boost either. And for the record I have tried it all!!! I even tried shifting no higher than 2k rpms and even 1.5-1.8k rpms depending on which gear/speed I'm traveling.

For the most part what I have learned is, its the acceleration that eats the most gas. So accelerate as "lightly" as possible. If your looking for an RPM target for shifting then I say around 2.5k rpms depending on circumstances of how fast your trying to go or road conditions.... Also for best cruising mpg, choose the highest gear possible (lowest rpms) without lugging the motor.

 

I get 23ish mpg daily city/highway combination with a stock 8 turbo, no cams. Cams are on the way though so I will assume the mpg will go up. I love this thread, makes me want to upgrade turbos. New excuse!

 

I get round 300 to 320 per tank hwy playin around alot built motor 280 cams a pt6765cea