Any harm in engine braking?

[Jamesgang]

I live in the Appalachian Mountains and have been driving here for 35 years. If you don’t use engine braking, you’ll cook a set of brakes every month. That’s just the reality of mountain driving. This is my first Jeep, and the number one reason I bought a Rubicon with 4.10 gears was specifically for controlled descents. If these Jeeps couldn’t handle high‑RPM engine braking, mine wouldn’t make it past the warranty.

Around here, everyone uses engine braking — it’s a necessity. I’ve never known anyone to have engine problems from it.

Sponsored

 

[Old Dogger]

I think both engine braking and using the brakes work well together, without overusing one or the other can enhance safety and performance and prolong the life of the brakes while keeping heat down. The engine is tough enough to take it and the 8 speed transmission is one of the best in the industry so in my opinion it’s all good.

100% agree! The diesel 18-wheeler trucks, use engine braking ongoing in the mountains. They install a Jake-brake, on their engines.

 

[bd100]

While towing the pop-up trailer I use as much engine braking as I can get because the trailer brakes are two 10 inch drums for a 2000lb trailer. They will overheat long before the Jeep brakes, and they make a noticeable difference in stopping distance. They work well so long as they don't overheat.

Image if your truck were 4000lb with four 10 inch drum brakes. That's about what it would be like.

 

[JeepinPete]

A lot of folks worry unnecessarily. Engine brake all you want, not going to hurt a thing. I've sat at 5k rpm down a hill numerous time, don't think a thing about it. The engine is under less stress engine braking than under power at the same rpm so what is the worry?

 

[Jeep Junkie]

A lot of folks worry unnecessarily. Engine brake all you want, not going to hurt a thing. I've sat at 5k rpm down a hill numerous time, don't think a thing about it. The engine is under less stress engine braking than under power at the same rpm so what is the worry?

Right, can't be as bad as WOT which I also do They say frequent WOT is good for our Pentastar

 

[Waldeck]

While towing the pop-up trailer I use as much engine braking as I can get because the trailer brakes are two 10 inch drums for a 2000lb trailer. They will overheat long before the Jeep brakes, and they make a noticeable difference in stopping distance. They work well so long as they don't overheat.

Image if your truck were 4000lb with four 10 inch drum brakes. That's about what it would be like.

This is a Centurion MK13 Tank, fully bombed up about 55 tons. It has 5 froward and 2 reverse gears, straight cut crash gear box. You have to double the clutch both up and down the gears, get it wrong and you are in the shite. On the down shift it is normal to "flick" a tiller (steering brake) in the neutral position to slow the gears to help mesh them.
There are 2 main brake drums, they are about 36" diameter and 4" wide. In an emergency they will last about 15 to 20 seconds tops. I only changed a set out I think twice in about 2 years, that's in a squadron of 13 tanks. The steering brakes are the same diameter about 3" wide. Engine braking was really the only way, on the level it was "easy", in the mountains in south Germany, not so much. The clutch was worked by a set of push rods and linkages from the front to the back of the tank, which were hard to adjust, start at the front and work your way to the back. Driving was a real work out didn't have to go to the Gym.

 

[AZ Hella]

There is absolutely no issue with engine braking, in fact you will maintain improved control of your vehicle should emergency maneuvers become necessary during steep descents. Which method would you use on a steep decent offroad? A) high gear and riding the brakes or B) low gear light to no brake application? If you picked the A, you're much more likely to lose traction have a problem, why does the same logic not work on-road. As long as you're not bouncing off the limiter, the engine is operating within it's design limits.

 

[Jeep Junkie]

There is absolutely no issue with engine braking, in fact you will maintain improved control of your vehicle should emergency maneuvers become necessary during steep descents. Which method would you use on a steep decent offroad? A) high gear and riding the brakes or B) low gear light to no brake application? If you picked the A, you're much more likely to lose traction have a problem, why does the same logic not work on-road. As long as you're not bouncing off the limiter, the engine is operating within it's design limits.

So true, specially if one is a 2 door with 3.5" lift and 37" mudterrains. I don't want to ever experience and find out what happens if I slam my brakes at 65 mph downhill. Not only downhill but also a curved highway. My aerodynamics and tires are so bad that I don't even neef to brake on a flat highway, Jeep loses so much momentum when I lift my foot off of the gas pedal.

 

[Jeep Junkie]

Look how bad my aerodynamics is.

 

[liquids]

On Mauna Kea on the Big Island, you're required to use it on the way down from 14k feet to 7k feet. Then they point a temp sensor at your rotor to see if you're required to wait in the parking lot before you can go further. I had rented a JLU. The guy said I had the lowest temp he had see all day. Barely above ambient air temp.

 

[TrailMax]

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

But how much cheaper after the pads fade and brake fluid boils?

If the hills are that steep, the transmission damage is probably going to be much like an air filter on a race car -- you're going to be tearing your engine (transmission) down between runs anyway so . . . ..

 

[Heimkehr]

But how much cheaper after the pads fade and brake fluid boils?

Fair points, but the informed owner can uparmor those components at reasonable expense. Semi-sintered or fully sintered brake pads, and DOT 4 or 5 in lieu of DOT 3.

 

[TrailMax]

Fair points, but the informed owner can uparmor those components at reasonable expense. Semi-sintered or fully sintered brake pads, and DOT 4 or 5 in lieu of DOT 3.

5.1 would probably be better (/jk)

Even then, even metallic can get too hot, and you risk needing 22" rims for that new rotor!

 

[Heimkehr]

5.1 would probably be better (/jk)

How embarrassing. I legit should've remembered that 5 is actually the silicone-based formulation.

 

[Gladiatorguy]

I'm getting the sense that engine braking in moderation, particularly when it supplements conventional brakes, is fine.

Is it not true that the cruise control will attempt to slow the vehicle down to speeds at which it's set if a hill is encountered by itself downshifting?

I'm getting the sense that engine braking in moderation, particularly when it supplements conventional brakes, is fine.

Is it not true that the cruise control will attempt to slow the vehicle down to speeds at which it's set if a hill is encountered by itself downshifting?

The cruise control will try to slow the vehicle down by downshifting, but my experience is that it is not very aggressive. Maybe go down to 5th. If that's not enough, it applies the brakes. If you are descending with the cruise control on, still above your set speed, and your instantaneous fuel economy readout hits 99 mpg, the vehicle is most likely applying the brakes to help control your speed.
I always shift manually going down mountain grades with cruise control off, occasionally tapping the brakes if necessary.
I have witnessed many drivers riding their brakes for 20-30 minutes down long mountain grades in Colorado. Sometimes you can smell the brake linings burning! I don't want to be in front of those guys. Often rental cars or vehicles with license plates from the flatlands.
I would rather sacrifice a few miles of engine life (if any) to have brakes when I really need them. Descending in slippery or icy conditions, it's best to be in 4wd, lest the rear wheels start slipping and you end up facing an unintended direction.

Sponsored