’07.5-17 6.7L CUMMINS
MAX HORSEPOWER: 490-520 HP TUNING: SMARTY OR EFI LIVE
While limited by a similarly sized (albeit variable geometry) Holset turbo, the 6.7L Cummins’s second-generation common-rail injection system supports slightly more power with custom tuning in the mix. Fitted with an upgraded clutch, it’s not uncommon for G56-equipped Rams to lay down 520 hp on the rollers—and we’ve even heard of some clearing 530 hp. For trucks with automatic transmissions, marginally lower numbers can be expected. The trick to keeping the factory 68RFE alive at 500 hp rests in good TCM tuning.