jimh425 wrote:
Seems like a few here don’t understand why diesels need an engine brake and a gasoline engine doesn’t. Read the link below if you want to understand it, or don’t. :D
https://en.m.wikipedia.org/wiki/Engine_braking
Only recently have consumer diesel trucks had exhaust brakes. I don't think any class 3,4 or 5 trucks have real engine brakes regulating exhaust valving in the head. My Ram has an exhaust brake. I think that's what Ford and GM use as well. This is different than a "jake brake" They are better for sure using up to 75% of the trucks engine performance to slow the engine rotation.
Diesels do not need an engine or exhaust brake. I have owned a few and the only one that has an exhaust brake is my current one. The others managed to not run into things and still move stuff.
Gas engine downshifting and the manifold vacuum created to resist the engine is nothing like the resistive force that exhaust brakes provide.