Did't run the SMS challanger because of no DR. shaft loop, but ran the SRT8 with the 275/50/17 Drag Radial's and turned a best 13.30. thaught it would do high 12:89 at least. The 1/4 mile readout in the car seemed to be off by Et 0.30 on the higher side every time. 0 to 60' was low 2.'s. the best was reaction time, got the hang of it, from .4?? to a .017. That's with automatic. SMS would be now Stick, need to get the hang of that.