Any harm in engine braking?

[Jeep Junkie]

Guys, so I just did made this video. 2nd gear, 3,300 rpm and oil pressure at constant 80 psi. Oil temp got to 213 degrees eventually, just one brake application when I got to the bottom of the hill before the light. Used my Tazer to cool the oil to a nice 197 degrees afterwards.
This is steep, camera is not doing justice.
What do you think?


In that space yesterday morning a cop was standing with his speed gun while I was doing 20 mph in 2nd gear

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[Blacksport]

Guys, offroad I always drive downhill in 4Lo and 2nd or 3rd gear. But these days even in town I engine brake in 2Hi and 2nd or 3rd gear when going downhill. Any harm in doing that specially when engine screams to 4000 or 5000 rpm? When I use my brakes it feels like they get stressed by my 37" MT's. So I want to make my brakes last long.
Thank you!

Use engine braking sparingly...brakes are MUCH CHEAPER than engines & transmissions!

 

[wave26]

Thanks. I use Pennzoil Ultra Platinum on steriods AKA Pennzoil Platinum Euro 0w40

Yes, that's BMW LL01 certified oil. If your Jeep came with N55 motor, you are all set.

 

[AFD]

That is a lot of RPM for engine breaking, maybe use a little the break to keep it a lower rpm.
Funny as the automatic version do some engine breaking to a certain degree.
Hybrid are doing it a lot (regenerative), my e-torq really enjoy going down hill to a degree that I need one heck of incline to not loose speed while not even touching the break.

Yes, on all but the steepest hills around here, my eTorque will actually lose speed while going down hill unless I just very lightly keep my foot on the gas. It's kind of a weird thing, but you get used to it pretty quickly.

My last vehicle was a manual and I never had any motor/drivetrain problems from dropping down a gear (or two) to slow down, keeping the RPMs within reason. Put 100k miles on it in over a decade of daily-driving and only ever needed to change the brake pads once, and that was likely only due to hitting them good once a day to warm them up and scrub any surface rust off the rotors (plus the very occasional hard braking to avoid deer and idiot drivers).

 

[Heimkehr]

even in town I engine brake in 2Hi and 2nd or 3rd gear when going downhill. Any harm in doing that specially when engine screams to 4000 or 5000 rpm?

Brake pads are considerably less costly than are transmission repairs.

If you want to have fun with engine braking, buy a motorcycle.

And for goodness sake, have a bit more mechanical sympathy for your vehicle.

 

[Jeep Junkie]

Guys did you watch my video? So you mean that's bad?

 

[Grayhound]

I paid to have engine braking as part of my tune on the diesel.
Keep rpms out of redline and you’ll be fine.
I’ve always understood engine braking is necessary for mountain driving. Seattle counts as mountain driving.

 

[Pape]

Here is some clarification about reducing the rpm.
Personally when I was driving manual the compression breaking (not sure it goes by that name in your neck of the woods) was the same as my shift point. So if my shift point for that engine was 3k rpm that engine breaking was to be keep under 3k rpm.

 

[Decreasing Dave]

Guys did you watch my video? So you mean that's bad?

I couldn't get past the fact that you were doing 20 in a 25 long enough to care about the engine braking.

 

[GabeBoyTheGreat]

I think you are fine in the video that you posted, as long as you are ok with driving that slow. I like to keep mine under about 3,500 RPM when engine braking; if I start to climb past that, I will tap on the brakes to slow it back down.

The issue with low speeds is that the lower gears of the 6MT are spaced very wide, which makes it difficult to find the right gear. I find that I have to choose between a gear that is too low and slowing me down (like your video), or one that is too high and I have to rely on brakes in addition to the engine braking.

Maybe try the same hill going down in 3rd gear. You will have to use brakes as well. It is not ideal, but in a situation like that, I would utilize engine braking only until I get too fast for comfort, at which point I will apply moderate brake pressure for a short period of time, hopefully enough to slow me back down. Then I release the brake pressure to give the brakes a chance to cool and go back to using engine braking only. Then the cycle just repeats itself.

The main thing you want to avoid if possible is riding the brakes down the entire way. You risk damaging your brakes if you ride them down all the way.

To summarize, you should use a combination of engine braking and regular braking, and try to keep your RPMs at a reasonable level.

 

[Jeep Junkie]

I think you are fine in the video that you posted, as long as you are ok with driving that slow. I like to keep mine under about 3,500 RPM when engine braking; if I start to climb past that, I will tap on the brakes to slow it back down.

The issue with low speeds is that the lower gears of the 6MT are spaced very wide, which makes it difficult to find the right gear. I find that I have to choose between a gear that is too low and slowing me down (like your video), or one that is too high and I have to rely on brakes in addition to the engine braking.

Maybe try the same hill going down in 3rd gear. You will have to use brakes as well. It is not ideal, but in a situation like that, I would utilize engine braking only until I get too fast for comfort, at which point I will apply moderate brake pressure for a short period of time, hopefully enough to slow me back down. Then I release the brake pressure to give the brakes a chance to cool and go back to using engine braking only. Then the cycle just repeats itself.

The main thing you want to avoid if possible is riding the brakes down the entire way. You risk damaging your brakes if you ride them down all the way.

To summarize, you should use a combination of engine braking and regular braking, and try to keep your RPMs at a reasonable level.

3rd gear would have taken me to 35 mph which is still fine, cops look for 45 mph drivers. A combination of 3rd gear and some brake application would be the best strategy. I will make another video tomorrow

 

[AndySpill]

I get:

* That all moving parts are subject to wear and tear.

* That engine breaking will cause more of that wear and tear than if you strictly use foot brakes.

* That foot brakes are easier and cheaper to replace than the components that are subject to wear and tear from engine breaking.

But this said, if you engine break in moderation (say on an automatic), and not subject the engine to RPMs much different from those an automatic transmission would normally experience accelerating smoothly from a red light to local traffic or even highway speeds, would most people sight that as an acceptable level of strain from engine breaking?

TIA

 

[GabeBoyTheGreat]

I get:

* That all moving parts are subject to wear and tear.

* That engine breaking will cause more of that wear and tear than if you strictly use foot brakes.

* That foot brakes are easier and cheaper to replace than the components that are subject to wear and tear from engine breaking.

But this said, if you engine break in moderation (say on an automatic), and not subject the engine to RPMs much different from those an automatic transmission would normally experience accelerating smoothly from a red light to local traffic or even highway speeds, would most people sight that as an acceptable level of strain from engine breaking?

TIA

Moderate engine braking has always been acceptable and sometimes required depending on the roads. My driving school instructor in high school taught me about engine braking even in an automatic. Maybe it causes more wear, but if I have to replace 4 sets of pads/rotors every time I drive down the mountain, the cost will quickly outweigh the cost of any additional wear from engine braking.

I'd say a good rule of thumb is any RPM that you are comfortable cruising at should be fine for engine braking. Personally, I don't like going above 4,000 RPM for cruising, so that is about my comfortable limit for engine braking. If I start to get close to that limit, I will slow myself with the brakes, then release the brakes and coast using only engine braking. The engine braking alone may not be enough to hold a steady speed, but it will significantly reduce the rate of acceleration, and as a result, reduce the rate at which brakes will need to be applied.

I have seen cars with modern automatic transmissions engine brake as high a 4,000 RPM, so I am comfortable with that.

 

[GabeBoyTheGreat]

3rd gear would have taken me to 35 mph which is still fine, cops look for 45 mph drivers. A combination of 3rd gear and some brake application would be the best strategy. I will make another video tomorrow

In that case, I would probably use the brakes to slow down to maybe 30 or 25, then release the brakes and rely on engine braking until I hit 35 again. That's just me.

 

[UniqueUserName]

I live in the Rockies. I engine brake every time I drive, otherwise I'd be cooking the brakes constantly. I keep it below 4K rpm and stab, then release the brakes when it starts to get faster. With my truck, I just keep it in tow/haul mode and use the brakes to get it to downshift and it holds.

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