We all know you can spare your brakes by downshifting (even in an automatic), but that it’s silly since a transmission is more expensive. My question is this (I have an 07 Altima with CVT, but this may apply similarly to conventional automatics with auto-manuals): does downshifting to decelerate negatively affect the transmission? It seems like it should , but if done easily within the tolerances of the transmission, would it?
I actually just viewed the DVD that came with my 08 Altima Coupe and they specifically said that manually downshifting to slow yourself on a hill was an acceptable application of the slap stick mode of the CVT. Is it harder on the transmission, of course it is. Is it within acceptable use parameter, well I don’t think that they would have shown it in the users DVD if it wasn’t.
The big question is whether or not the deceleration load on the transmission is more or less than standard driving.
Most drivers don’t exceed power consumption of 3-4 gallons per hour, or 80 horsepower in use, during any part of the their commute. They also don’t use much more than 2.5 GPH, or 50 horsepower, during their cruising at highway speed.
You’re not going to noticeably decrease your transmission life if you exert less than 50 horsepower worth of braking with the tranny.
Hijack: I test drove one of the coupes, but went with the sedan because I didn’t want to wait for whatever coupe was coming in (3 month wait). It was pretty sweet. 