Stupid Question.

Ok, my father says that all automatic cars have the same shift points (MPH), and i say that it’s impossible because not all cars are the same due to HP,etc. So whos right?

hp doesn’t have to do with it …gear ratios do.

shift points will vary from vehicle to vehicle based on transmission and differential gearing…which varies the shift points based when you look at mph. Even then, shift points can vary on your rate of acceleration.

Even the shift points within the same vehicle will be different whether your accelerating rapidly or slowly. Some shift points are set electronicly, some through engine vacuum…etc.

if you’re interpreting “shift point” as the engine redline, and not when the automatic transmission actually shifts the gears. Redline can be effected by HP, but has more to do with the stroke, displacement, Rotational mass, balance and component strength within the motor.

tell your dad he’s wrong and that you will be smarter than him when you grow up.

they vary WIDELY


edit: stock 1-2 upshift point for an automatic sho, because i have them on my computer. notice the wide variations in upshift speed, and this is just one cars strategy

at least the title of this thread wasnt wrong or stupid

sad thing is he was a mechanic and worked with cars, peroid.


key word being WAS…as Lafengas so educatedly explained…shift points vary on many many things…my old auto Max would shift out of 1st at 3k if i was light ont he gas and 5500 and WOT

not to mention with modern day autos, a few keystrokes and you can set the shift point to pretty much anything you want. hell… even in older transmissions it wouldn’t be universal for the reasons lafengas pointed out

your dad has some good stuff :smiley: