Re: 6 speed auto
Nissan tranny? Huh? All transmissions are made off the same principles. The torque converter decides what gear to be in according to your road speed and angle on the pedal. I wouldn't use 'low' on the selector unless your below 35mph. On six speed transmissions you generally have two over drive ratios. Downshifting the transmission to a lower gear manually when going downhill is fine, but unnecessary in todays modern cars. Only if you carry heavy loads or tow should you increase the rpm. The only benefit of increasing the rpm is when carrying a fully laden vehicle, and/or towing to keep the tranny from overheating and causing damage. If it's just you and a couple passengers in the car, just leave it in Drive - the car knows what to do.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!