Engine Breaking, New Car

Pitter

Pitter
Contributor
:
2020 CX-5 Signature Azul Metalico
Have a brand new Signature with 500 miles on the odometer. To get to the city I have an eight mile drive down a mountain road with lots of curves. If I drive down in "Drive" I pretty much have to ride the breaks all the way down. I've found it more comfortable to place it in "Manual 2nd" so some engine breaking holds me back and I can give the breaks a rest. The RPMs in 2nd reach about 3200rpm on the brief straight stretches before I break for another curve. My question is since this is a brand new car is there any negative associated with using engine breaking as I have described? Or should I say breaks be damned and ride them on the trip down with vehicle in "Drive" mode?
 
Easier to replace brakes than an engine.

I think the manual states what gear you should be in at a certain speed. Also, the transmission is smart enough to not let you downshift past a certain point
 
Mine will downshift at least to third gear by itself if Im on the brakes going downhill. Further, theres a reasonable theory Ive heard that says you need engine braking to properly seat your rings and break in your engine.
 
Engine braking is the BEST way to properly break in an engine. That and varying rpm. I would use engine breaking as must as possible over the first 500-1000 miles, but switch gears from time to time to vary rpm as well.

Have used this approach on every new vehicle weve had, the oldest of which is a 6spd 2008 ram v8 with 375k miles (bought in 08 with 12 miles)
 
Thanks for your replies.I would like to continue to use second gear up to 3200rpm for most of the down hill run if that doesn't imply any long term ill efects.
 
You should be getting engine braking automatically as the transmission senses you are using the brakes going downhill. Mine does that after a set period of time in the same situation.
 
I tried going down the mountain in drive again and I was breaking all the way. Never sensed any holdback from the engine.
 
If youre on the brakes going downhill, flip the shifter left so that the IP display shows your gear instead of D. I bet itll be something lower than 5.
 
Personally I don't see a problem and I do it also. I don't think engineers would have designed the transmission with that capability if it was bad for the tranny. However with that said some people would point out that replacing brake parts is a lot cheaper than having the tranny repaired!
 
Why dont you just activate the cruise control and let the car take care of all the details? You got smart cruise control so it will adapt to traffic in front of you. If you set the cruise control to 35 or whatever, it will not exceed that speed. And between curves you can still use the gas pedal to speed up a bit. When you lift off the gas it will drop back down to the set speed.

You paid for the tech so you ought to use it!
 
Why don*t you just activate the cruise control and let the car take care of all the details? You got smart cruise control so it will adapt to traffic in front of you. If you set the cruise control to 35 or whatever, it will not exceed that speed. And between curves you can still use the gas pedal to speed up a bit. When you lift off the gas it will drop back down to the set speed.

You paid for the tech so you ought to use it!

Good idea, but since he doesn't have front radar I think his cruise control is dumb and won't brake. Worth a try.

I'd go down in manual. As long as you don't ovverrev, you're not hurting anything.
 
Good idea, but since he doesn't have front radar I think his cruise control is dumb and won't brake. Worth a try.

I'd go down in manual. As long as you don't ovverrev, you're not hurting anything.

With the automatic transmission logic, it is impossible to overrev the motor. Mazda engineers designed it to be foolproof. (bow)
 
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With the automatic transmission logic, it is impossible to overrev the motor. Mazda engineers designed it to be foolproof. (bow)

What happens if you're accelerating downhill with your foot off the gas in a lower gear and you reach redline?
 
Have a brand new Signature with 500 miles on the odometer. To get to the city I have an eight mile drive down a mountain road with lots of curves. If I drive down in "Drive" I pretty much have to ride the breaks all the way down. I've found it more comfortable to place it in "Manual 2nd" so some engine breaking holds me back and I can give the breaks a rest. The RPMs in 2nd reach about 3200rpm on the brief straight stretches before I break for another curve. My question is since this is a brand new car is there any negative associated with using engine breaking as I have described? Or should I say breaks be damned and ride them on the trip down with vehicle in "Drive" mode?

Use the engine for braking in your situation. At 500 miles, your engine is pretty close to as "broken-in" as it will get. The engine and transmission are lubricated and liquid cooled. It will be fine.
 
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