[oldtexasdog]

I will be taking my 2020 M550 into the Smokies then the Rockies for a lot of mountain driving this summer. When I took my Mustang GT with manual tranny I used to down shift into 3rd or 4th (3K to 4K RPM's) and let it drag so to speak on the downhill runs rather than constantly applying the brakes. Can I do the same using the paddle shifters on my M550 without messing up the transmission? Some of the down hill runs can be a mile or longer. If so what RPM should I look to keep it at?

[NGT2]

I can’t answer your specific RPM question, but I did this a lot in my 540 driving two lanes from Jackson TN to Nashville. Not exactly the same degree but I never had any problem with it.

I bet you’ll have a fun time, regardless.

[Opie55]

Originally Posted by oldtexasdog

I will be taking my 2020 M550 into the Smokies then the Rockies for a lot of mountain driving this summer. When I took my Mustang GT with manual tranny I used to down shift into 3rd or 4th (3K to 4K RPM's) and let it drag so to speak on the downhill runs rather than constantly applying the brakes. Can I do the same using the paddle shifters on my M550 without messing up the transmission? Some of the down hill runs can be a mile or longer. If so what RPM should I look to keep it at?

"A mile or longer." That's quite an understatement if you are coming here to Colorado. For example, the downhill run after you exit the Eisenhower tunnel westbound on I-70 is 11 miles. I have driven many miles in the Rockies and I generally do not do what your are describing. I only downshift if I am trapped behind someone riding their brakes. Otherwise, on a road like I-70 that has long curves but no switchbacks I just let the car run and reign it in as necessary with some gradual braking, but I do not ride the brakes. Coming down hills like that at around 90 mph is normal and you will not be alone by any means. On two-lane roads with lots of tighter turns I drive pretty much the same as I would if the road were flat - I just brake going into the curve - it's just that with gravity assist you don't need to accelerate as much coming out of the curves. But I never truly find myself riding the brakes. You sort of find a natural speed for the road you are on.

[BMW012]

you can also put it into sport or sport+ and it should naturally apply more engine braking.

[NVRfollo]

Brakes are cheaper to replace than the ZF transmission

[adhrp]

Originally Posted by Opie55

"A mile or longer." That's quite an understatement if you are coming here to Colorado. For example, the downhill run after you exit the Eisenhower tunnel westbound on I-70 is 11 miles. I have driven many miles in the Rockies and I generally do not do what your are describing. I only downshift if I am trapped behind someone riding their brakes. Otherwise, on a road like I-70 that has long curves but no switchbacks I just let the car run and reign it in as necessary with some gradual braking, but I do not ride the brakes. Coming down hills like that at around 90 mph is normal and you will not be alone by any means. On two-lane roads with lots of tighter turns I drive pretty much the same as I would if the road were flat - I just brake going into the curve - it's just that with gravity assist you don't need to accelerate as much coming out of the curves. But I never truly find myself riding the brakes. You sort of find a natural speed for the road you are on.

This is exactly how I do it, including during my recent drive in the Smokies.

[ezaircon4jc]

In a previous car (Lincoln LS, if it matters) I drove down Pike's Peak using 99% engine braking. There's a ranger station most of the way down where the ranger checks your brake temp; he uses a temp gun on the rotor. If you're over a certain temp (I don't remember the value), you have to wait at the gift shop for 10 minutes. My rotor temp was so low (around 100º IIRC) he asked me if I used my brakes at all! Neither the trans nor the engine suffered any ill effects.

[Opie55]

Originally Posted by ezaircon4jc

In a previous car (Lincoln LS, if it matters) I drove down Pike's Peak using 99% engine braking. There's a ranger station most of the way down where the ranger checks your brake temp; he uses a temp gun on the rotor. If you're over a certain temp (I don't remember the value), you have to wait at the gift shop for 10 minutes. My rotor temp was so low (around 100º IIRC) he asked me if I used my brakes at all! Neither the trans nor the engine suffered any ill effects.

That is just a way to get you into the gift shop. There are way steeper hills than Pike's Peak and no place else has anybody checking your brakes, let alone telling you to go into a gift shop. When I first saw that person I laughed and drove on.