2015 Ram 2500 4x4 Diesel ext cab 6.7

[Bob Nelson]

I can't find any information on the Exhaust Brake, weather I can leave it on at all times,does it being ON affect my fuel mileage. On my 2004 I added the Pac Brake with the 48RE xmission and left it ON all the time,never had an issue with it. Should I run it MAX position or AUTO if it will not decrease my fuel mileage

 

[GSykes]

I run with it on all the time "MAX", every time I start it I push the button. It exercises the vanes and helps keep the shaft clean. Last thing you need is for it to start sticking. I did the same with my previous 2008 truck as well. Used the auto position numerous times but decided to use the MAX setting, either will work I guess. In the manual it tells you the difference between the two settings but doesn't specify on or off. Just my thoughts.

 

[gsbrockman]

"ON" will keep the exhaust brake on until the torque convertor unlocks.....generally around 1,000 RPM.

"AUTO" will maintain the proper amount of braking required to keep the vehicle at whatever speed you initially hit the brakes.

"AUTO" will also continue braking as long as one's foot is on the brake....down to 1,000 RPM.

 

[JR2]

"ON" will keep the exhaust brake on until the torque convertor unlocks.....generally around 1,000 RPM.

"AUTO" will maintain the proper amount of braking required to keep the vehicle at whatever speed you initially hit the brakes.

"AUTO" will also continue braking as long as one's foot is on the brake....down to 1,000 RPM.

Auto also appears to apply the while the cruise control is on to reduce speed while going down hill. It also appears to slow you down to the speed limit when your foot is not on the throttle (assuming you have Nav system.)

 

[Cummins12V98]

EB FULL & TH ON all the time!

 

[Mingoglia]

I'm another that turns on the full EB at startup, particularly since moving to GA where it's a lot hillier than AZ. I don't use tow/haul though when unloaded. Although the EB will work better in T/H, it doesn't drive as smooth unloaded.

As for operation, full is engaged anytime you're off the throttle and the T/C is locked (even when not on the brakes), and disengages at low speeds (others say low engine RPM, which may be the case). Auto is also engaged when you're off throttle and T/C is locked, but it will attempt to maintain the speed you were at when you got off the throttle. As was said in the case of cruise control it will attempt to maintain that speed.

The operation described above is new for the past 3 model years I believe. The prior model years with E/B had a slightly different function, with multiple settings. Figured I'd point that out in case others with older trucks describe how theirs works and it sounds different than yours.

 

[kthaxton]

and disengages at low speeds (others say low engine RPM, which may be the case).

I can say with absolute certainty, that mine disengages at a particular RPM (around 1100-1200 rpm), not a particular speed.

 

[LHarper]

I can say with absolute certainty, that mine disengages at a particular RPM (around 1100-1200 rpm), not a particular speed.

Mine too. Last one was also the same.

 

[Mingoglia]

I can say with absolute certainty, that mine disengages at a particular RPM (around 1100-1200 rpm), not a particular speed.

I was actually agreeing with you, maybe not in clear words. I never really put two and two together that it was based on RPM, and not speed.

 

[Badunit]

As to the question of fuel mileage, theoretically the EB should reduce fuel mileage as compared to coasting down hills without using any braking. Braking of any kind = removing energy from the system and turning it into heat. But if you compare the EB to using the foot brake to accomplish the same braking force then there would be no effect on fuel mileage.

My experience with the EB with an empty truck is that it brakes too hard on "full" for the hills I am on. This causes me to press the accelerator on downhill slopes which I wouldn't do if I was using the foot brake to control my speed. But with so many other variables, it is hard to tell if it has any affect on my fuel mileage.