[I've posted this same question in a hybrid forum but my RX is standard ICE)

I've always used the S position to downshift on long mountain descents but not at other times. It never occurred to me to use it in ordinary driving situations. For example, my house is at the bottom of a half mile slope - it's fairly gentle but it does require regular braking. Is it worth downshifting to save the brakes or does doing this create some other stress that I'm unaware of? Or is the benefit so minor that I needn't bother? Coming from the other direction is a much shorter, steeper slope.The same drop but in probably 150 yards rather than 1,000.

Thanks

 

I suspect you live in western NC with your description of the terrain. I live in western VA probably in very similar terrain. I always downshift on long downhill runs. If for no other reason than to not overheat the brakes. I do not think there is any downside to doing this. Our cars do detect the slope and downshift going downhill anyway. I, like you, do not use S for any other reason.

 

Nicely done. I’m outside Charlotte with regular jaunts to Boone.

 

Ahh yes, ASU. Been there many times.

 

Just keep an eye on engine RPM.

With the hybrid I just keep a consistent light foot pressure on the brake to regen, but for an ICE I used to follow brake and release ...[something made my family pretty upset].

Salim

 

Someone posted here awhile back that using a scan tool, trans temps rose while engine braking and concluded not worth the tranny wear and tear...brakes are cheaper. Ymmv.

 

Someone may have posted that, but I doubt it is true. Our cars downshift automatically going downhill anyway. It goes from 6th gear to 4th without any input from the driver. Happens when you apply the brake going downhill. Then you can take your foot off the brake and it will stay in 4th until you hit the gas again.

 

I agree with you, I doubt the transmission would overheat. Especially since while engine braking the engine is not actually burn much fuel if any. But I live in flat lands and can't really test it.

 

I had the same thought - that brakes are cheaper - but a few years ago I drove my Odyssey down this stretch without downshifting and it warped the rotors. The van was close to the end of life so I didn’t repair but I had major shuddering from then on.

 

One of the advantage of driving a hybrid is that you can softly ride your brakes all the time! Still, I down shift going down a hill. I have been doing it since my manual transmission days. Since my initial morning downhill drive is exactly one mile, I'd be happy if it warms up my transmission.