Is it bad to "Down Shift" a lot?

Heat generated in the trans would be negligible, if any. The only thing causing any amount of wear is the actual lurching, non rev matched downshift. My gf's Corolla will downshift when I lift off the gas going down a steep hill. It's a 4 speed auto so the ratios are far apart. When it shifts, the car lurches forward as the RPMs shoot up and it feels like it must be horrible for the trans. It annoys the shit outta me. A perfectly rev matched downshift however, is nearly unnoticeable.

 

Because, the torque converter on the Tacoma only locks up in 4th and O/D - so - in the first three gears while decelerating there is slippage in the converter, generating heat. In 4th and O/D, while decelerating, if the converter is locked up, the transmission temps will actually cool, but will rise if the converter is not locked up - throttle position sensor and engine load dependent. Another variable - even though the converter is generating heat when decelerating in say 3rd gear, the engine coolant temp is going down, transmission fluid is running through the radiator is affected by the decreasing coolant temps, still rising but at a decreasing rate.

 

You got your engineering degree from where???

 

I have done this in a 2015 Dodge 2500 and saw absolutely no big change in temps

 

It doesn't take an engineering degree to determine the intent of a design.

Me and my accounting degree would happily take you through a cost benefit analysis of downshifting vs braking though!

 

That would be sure to keep the power train engineers at Lexus, Mercedes, GM, and Ford in stitches for weeks. LOL

 

That is why engineers are not in charge of the money.

 

But does that heat matter more than accelerating. up the hill? No.

 

They are if they are the CEO. And unless you are the CEO at your company, you're not in charge of the money, you just count it. LOL

 

I probably should've left this thread alone at post #38.

 

Cased closed on the accountants guess.

 

Ok fair enough, I'll take his word for it, my argument is incorrect. Downshift away friends!