my dad has the smart jr and a dpf delete kit on his 08 6.7, awesome power and great fuel mileage with 0 problems. i hauled about 12k lbs a while back with it on the 40hp economy tune and had plenty power to get moving when needed.

 

Smarty with a few mods and TNT and it will haul azz!!!!!!! Whops it does spin a real lot.

 

MY SMARTY JR & DELETES ADDED ENOUGH POWER TO SPIN THE STOCK CLUTCH ON THE 60HP TUNE