Hi Ray, I’m hoping you can settle an argument I’m having with a fishing buddy. When I’m driving my Tundra in the mountains, particularly when I’m pulling my boat, I often go into manual override mode to downshift. I do this when going downhill, when I’m slowing down to take a turn, or maybe when I miss the manual transmission of my old Dodge Powerwagon. To that my friend always says “brakes are cheaper than transmissions” or something to that effect. I also do this with my Lexus is 350. I say the vehicle is made for this and I’m doing no damage. Please settle this for me, so I can focus our arguments on who caught the biggest fish!
If Ray posts here it’s under an alt. I’m not even sure he reads our posts. That said, Ray has answered this question in the past and he agreed with your buddy.
That is a foolish statement, it suggests that your friend knows little about automobiles. Transmissions don’t use friction to slow the vehicle, it is the action of engine braking that slows the vehicle. There is less of a load on a transmission while engine braking than while accelerating. The transmission will not burn-up the way your brakes will.
Brakes rely of friction, brake pad wear multiplies with high heat and overheating the brakes causes the rotors to warp. Some of my customers warp their brake rotors each time they drive in the mountains because they don’t understand the need to downshift.
Lexus would not have mounted paddle shifters on the steering wheel if shifting were to cause damage to the transmission.
Here is a Tom and Ray discussion on downshifting;
I find it interesting that Ray’s advice apparently changes with circumstances. In an installment of the newspaper column a few years ago he wrote that downshifting creates internal wear on the transmission and it’s preferable to use the brakes because any potential repair is cheaper. On the subject of paddle shifters in the same column, he wrote that vehicles are equipped with them because buyers think they’re cool but they shouldn’t actually be used.
I have been driving for 55 years, and I have always downshifted my automatic transmission on steep downgrades. And, I have never had to overhaul or replace a transmission on any of my vehicles.
Relying solely on the brakes on steep grades while towing can cause the brakes to overheat and fail.
OP is driving a 9 year old truck and towing heavy loads, He does not report any transmission problems. His friend is offering advice, but it’s the OP’s truck and he decides. What he is doing is good, careful driving, and well within the design limits of his truck. Laying guilt on him for being careful is just nonsense, and his fishing buddy should be told to stop nagging about something that’s not his concern.
I had to give my sister-in-law a quick and urgent downshifting tutorial coming down a mountain pass, in a minivan full of people, when the brakes started to groan and shudder.
I’m not normally a back seat driver, but I had to speak up.
Bill has not posted since the 15th but the part about slowing for a turn makes me think that he might be doing the electronic shifting when there is no real benefit . Also it is possible that the shifts are not done as smooth as they should and unnerving the passenger.