Uh, yes there is. Mercedes need to be revved to 2300-2500 to get full use of the brake. When it's up there, it's the most powerful jake on the market.

Any engine brake is more effective at higher RPMs. As for being the most effective on the market... I DOUBT IT. An N-14 will hold together up to 3500 rpm. (according to my mechanic) Any idea how effective mine would be at 3000 rpm??? Sorry, Bud, but wimpy at 1800 means just plain WIMPY.

depends on the design. You can't just compare two jakes at 1500 rpms and say one is wimpy and the other isn't. Mercedes use a unique turbo design to acheive their 600 hp jake ability.

Most engines will probably "hold" to 3000 rpms or so. The camshaft profiles aren't designed for this however. Valve float could definitely be a problem as well.

I didn't say anything about Hills-I was talking about Jakes for slowing down. You don't use Jakes for just hills.

That's right I seen a guy use his Jake while pulling into the fuel lane at Steel City today. :lol:

yea
 

and if anyones gonna rev there tuck up that high, somethings wrong

Yeah-actually see Idiots using their Jakes within the truck stop and Bobtailing no less-boneheads

Yeah-actually see Idiots using their Jakes within the truck stop and Bobtailing no less-can tell how long they've been driving when they do that stuff.

Ok guys, I have a 06 Columbia with the 450 mercedes. I am averaging around 7.6 mpg with it. i pull a tanker and run at max weight all the time. i do not however pull alot of hills which does help on the mpg and i keep my idling down to the bare minimum. The exhaust brake which is what they have and not your standard jake like on most trucks. They work great when used correctly and, yes you do have to have the rpms up much higher for max braking.
The problems i have had on the engine itself has been pretty minimal. Exhaust manifold gaskets were changed twice. 2nd time because the first tech did not install properly. mercedes has supposedly corrected this problem and updated the gaskets on all the new trucks. they also relocated the egr sensor, no biggy there. it pulls great as far as i am concerned for what i do. i have a fuller 13 spd on 3:42 rears runnin on low pro 22.5 rubber. pretty good set up as far as i am concerned. i run around 1400 rpm at 65 mph. only thing i hate is the fan comes on constantly when running around town and stop lights. seems to be typical of these egr engines.

As far as I know, ALL engine of Jake brakes operate off of the exhaust. :?