Community Forums

Paulraymond · 08-10-2019, 06:05 AM

Does anyone know if by leaving the engine brake on permanently uses more fuel?

nathaniel · 08-10-2019, 06:28 AM

It doesn't, but I wouldn't leave it on all the time unless in mountains.

NevadaNick · 08-10-2019, 06:31 AM

It does use more fuel because you will always be tipping the throttle back in instead of coasting.

exrench · 08-10-2019, 06:58 AM

Quote:

Originally Posted by Paulraymond

Does anyone know if by leaving the engine break on permanently uses more fuel?

What caused it to break in the first place?

Paulraymond · 08-10-2019, 07:04 AM

Thanks for pointing that out.

Quote:

Originally Posted by exrench

What caused it to break in the first place?

Cousin Ed · 08-10-2019, 07:14 AM

If you engine brake is on all the time, your service brakes will not get enough use and they need to be used.

jacwjames · 08-10-2019, 07:21 AM

I tried to leave my engine brake on but did not like the way the coach would kick into braking everytime I let my foot of the accelerator. It seemed like I had to have the throttle in a very narrow range by providing a slight pressure with my foot, it was very fatiguing.

IMHO I also believe this action would cause higher fuel consumption since the activation of the engine brake definitely slows the coach so when I push on the throttle to recover the fuel consumption is higher. I'd be hard pressed for anyone to explain why this wouldn't cause higher fuel consumption.

I use cruise control and I do use the engine brake a lot, to activate I tap the brake to deactivate the cruise and then flit the exhaust brake switch which is located on the left side drivers console. I've trained myself not to even have to look at the switch.

will stevens · 08-10-2019, 07:41 AM

Restricting the exhaust with the use of the exhaust brake will raise the EGT (exhaust gas temperature ), as well as raise the water temperature.
When truckers pull a long steep hill, the EGT and water temperatures go up. It is recommended to stop at the top and let everything cool down a bit before using the exhaust brake on the trip back down, as the exhaust brake will heat things up same as the climb.
I would not run with my exhaust brake on all the time as I want my exhaust system open. I only use on long downhill runs .

ScoobyDoo · 08-10-2019, 07:59 AM

Can RVs be programed as to when the brake comes on? All 3 of my drive by wire diesels (2Cats, 1 Cummins) where programed so if the brake switch and cruise control where on (CC did not need to be set) I could step of the go pedal and coast, but as soon as I touched the brake, would jake until back on go. (or lower RPM limit) I liked that setup.

Milford 47 · 08-10-2019, 12:20 PM

I agree on not having the engine brake on all the time

Where are all the guys we had the big discussion with that leave them on all the time? Why so quiet now?

Crasher · 08-10-2019, 12:44 PM

I run with the EB on low all the time unless on wet slippery road conditions. I have it programmed to engage whenever the service brakes are used or when the cruise control is disengaged, but just a light tap on the accelerator turns it off. It's very useful in managing speed. In the mountains, I will flip it to High to maintain speed while descending steep grades or when in heavy city traffic for when that idiot pulls into the gap ahead of me and decides to slow down. It's there to use and I see no disadvantage to using it anytime I need to slow down. 68,000 miles on a previous coach and 62,000 on this one so far and the brakes work great when I need them stop quickly.

bobmac · 08-10-2019, 01:57 PM

Yes, the engine software can be changed. I had mine reprogrammed so I could coast when I released the throttle and when I tapped the brake pedal, the engine brake was activated until I either stopped or applied the throttle again. Visit your Cummins dealer for reprogramming the coach software.

Dav L · 08-10-2019, 02:54 PM

I bought a foot switch to wire into the engine brake on / off circuit. I'll leave it off by default and engage on demand with a left foot. Yet another project on the list of many.

jcussen · 08-10-2019, 03:33 PM

Quote:

Originally Posted by will stevens

Restricting the exhaust with the use of the exhaust brake will raise the EGT (exhaust gas temperature ), as well as raise the water temperature.
When truckers pull a long steep hill, the EGT and water temperatures go up. It is recommended to stop at the top and let everything cool down a bit before using the exhaust brake on the trip back down, as the exhaust brake will heat things up same as the climb.
I would not run with my exhaust brake on all the time as I want my exhaust system open. I only use on long downhill runs .

Curious why the the egt's and water temps will rise. Unless your coach is very different than others, exhaust brake will not activate if you have any throttle on. So with practically no fuel being burnt, what causes the egt and water temps to rise?
Have used exhaust brake on many long grades, and have never seen this.