So just looking for food for thought.
Currently I'm running a dynomax turbo with a drop .
If I put my tail pipe back on won't this help my mpgs
If I'm correct I don't have enough back pressure.
Reason I'm asking last winter I was getting about 17-18mpgs on 3 inch lift 31s and stock exhaust and tailpipe.
This year I'm getting 14-15 on 31s with a dynomax turbo and a drop no tail.

 

You should always run a tailpipe because of the safety factor of having exhaust fumes coming into the cab of the XJ instead of behind the rear bumper.


I would expect the MPG to be a different issue other than the exhaust, even type of fuel used could be the cause winter vs. summer blend.