Hello. As the title says, I'm only getting 150+ miles on my tank or 10-12 mpg. This has never happened before as I was getting 230-250 miles a tank. If the information helps, all of my fuel system is stock; injectors, fuel pump, regulator. I am currently on stock turbo too. Mods list are: ShepTrans Stage 3 w/ 4.11 FD, ETS I take w/ MAF, and AMS 3.5 intercooler. Anyone's help is highly appreciated.

 

A tune never hurt

 

It's most likely a boost leak or something similar.

 

+1 do a thorough inspection of all the vacuum hoses and intercooler pipping followed by a boost leak test.

 

Thanks for the assist, fellas. I'll do a boost leak as soon as I can. Hopefully it is just that.

 

Check your throttle body shaft seal too