Leave engine brake on?

I think what the OP was asking about was leaving it on all the time, which would then engage every time you lift off the throttle unless you have your foot on the clutch. One of the replies was simply stating that if you are letting the jake engage when you don't want it to, just because you don't want to turn it off, would be wasting fuel.

 

In traffic there are many times where coasting is beneficial. Also coming up to a red light that may turn green before you get there. Leaving jake on doesn't allow you to easily coast and this will slow you down weather you want to or not.

Now, on my truck, On a down grade, accourding to my scan gadge.... With jake on low no difference in mpg is noticed. When put on high, mpg is about a quarter of what it is on low without much immediate speed change. I've been told the turbo is used on the high setting and it uses fuel to brake.

 

well youve been told wrong jakes do not use fuel .the reason scan gauge shows less mpg is youre giving up free rolling and boost is just compression spinning turbo otherwise u would be accelerating if fuel was added to compression stroke

 

I only run mine on down grades, besides I was taught if the road is slick you want to minimize braking and accelerating as much as possible to avoid losing traction (granted there are some cases where acceleration helps you gain traction)

 

Well on low jake, going 65 down a hill, my mpg is 175mpg. As soon as i switch to high before the speed really drops its around 35mpg. A 5 mph difference wouldn't affect mpg that much. Off is about the same as a low.

 

I turn mine off unless I know I'm going to need it because it prevents me from setting my cruise control. On flat highway, in good weather, with adequate following distance, CC is nice to have.

 

shut jake off and kick into nuetral i bet mpg drops because now you are using fuel to keep engine idling where as before driveline was turning it for free. for chits and giggles ask the guy you bought scan gauge from if jakes burn fuel lol

 

Well i also get a check engine light if i use the jake on max to long. (not when on low) Something to do with turbo not responding correctly....So mine may be different. In Neutral mpg stays at 175

 

:smt017 OH, wow, Have I got a lot to learn...That was like reading a foreign language, far as the technical info goes.

 

Total bs.....leave your jake on when cruising, it will help you stop in an unexpected emergency where you wouldnt have time to flick it on for that extra stopping power. It does not hurt your mpg. Also use it during downshifts, but shut it off while upshifting, until you are good enuff to upshift without engaging it. It is an excellent safety feature, and should be used to your advantage whenever possible.