It's spring and time to continue my testing and tuning (now with my soon to be installed wideband a/f sensor and powerlogger) Always looking to protect my precious rebuilt motor so I still anguish a bit about doing the whole run in drive even though the calculators say I am way safe even up to 115 mph with my 27 inch MT's. I am planning to tune in drive (i.e. 3rd gear) but I was wondering about the ET and mph penalty for using OD. My experience last year was that in OD the car shifted to 4th just before the light (maybe 100-150 feet) and I felt a noticeable let down as the rpm's fell that 30%. I suspect the effect that late in the run would be to hurt mph more than ET. What do you all think?