Hey All. Ive been reading a lot on here about the new superduty just to learn more about them. My Father in Law just bought one (2017 SCAB LB Lariat) and we'really wondering about the exhaust brake. I own a 16 3500 CCLB RAM Cummins. They are very much different and I can't really help him with it. The newest Ford diesel our friends have is a 13. I'm not looking to start any issues with brand wars but am trying to figure it out and my only comparison is my truck.

The cummins is a much louder engine and doesnt rev nearly as high. It shifts at 20-2100 rpms unless your really pushing it and it will go higher even with tow haul engaged. However with tow haul engaged it doesn't go lower than 1400 rpms or it down shifts. The exhaust brake is fairly loud and you can hear it working along with feeling it. I barely ever hit the brakes until about 20mph or so when it finally cuts out. It holds me back on a 10% hill at 25 mph with no issues.

My FIL last truck was a 2012 F350 6.7 SCAB LB lariat with only had the transmission braking so we both expected it to now be much more like my truck. We live on the same road and going down the 10% hill with tow haul and exhaust brake engaged his truck doesn't even downshift like the last one. It performs worse and will go to 1000rpms. I'm guess the low rpm is why the exhaust brake isn't working right because mine wouldn't work either at that low rpm. It is a fairly new truck with less than 500 miles so maybe it just needs a longer break in? Any of you guys have a similar issue? Any ideas would be greatly appreciated. If anyone's interested in any comparisons let me know as I feel I'm pretty unbiased and could be pretty fair.

 

The factory system is an engine brake and per the manual is for higher speeds, so you really shouldn't feel anything if you're going 25 mph. Page 221 and 222 of the regular manual cover it for you.

 

I know on my '16, it will only activate when the RPM's are above 1500, and it clearly works when above that level. The best way to utilize it is to manually shift the tranny down to keep the revs in the proper range. When you do that, the combination of the trans and the engine brake work very well. I assume the '17 is similar but likely improved.