Is anyone using the boxes from SPdiesel?
How are they compared to teh rest?
Does the fuel economy setting help MPG?

 

I've run an SP deisel box for well over 20k now....when I am drivign 'refined' and close to the speed limit at 68 I get 20-21 MPG with their elimitor box turned all the way up. This is also the same setting I used at a recent dyno event and the machine said 402 RWHP and 786 ft/lbs...also helped me run a 15.0x in the 1/4