JB4 question for those that use it

[Largefarrva]

For those of you with the JB4 tuner, I have a couple of questions.

Do you have to connect the app to the tuner every time you start the truck? Or does it just run the last map used?

As far as freeway driving at 70+ mph and driving at a steady speed…did the JB4 have any negative effect on gas mileage? Or was it the same as stock?

I would like to get the JB4 for some performance gains and especially to get get rid of throttle lag, but if I’m going to spend an extra $100+ per month on gas to go from 87 to 93 octane I want to make sure it’s not going to negatively impact my mileage on the freeway (80 mile commute to work each way) and I likely won’t feel like connecting to the tuner every time I start up the truck.

 

[LOWRMPG]

Very curious to see answers you get here, as I can't imagine anything that adds 100 hp and somehow keeps mpgs the same.

 

[HSKR R/T]

It shouldn't effect highway mileage, because the PCM will be working to maintain stoich A/F ratio. When cruising in closed loop. Depending on the timing changes, it may actually some. This is theoretical based on knowledge of how engine manage software works

 

[Largefarrva]

Very curious to see answers you get here, as I can't imagine anything that adds 100 hp and somehow keeps mpgs the same.

You must have missed the part where I said driving at a constant speed on the freeway. It isn’t going to be adding any hp at that point.

 

[Largefarrva]

It shouldn't effect highway mileage, because the PCM will be working to maintain stoich A/F ratio. When cruising in closed loop. Depending on the timing changes, it may actually some. This is theoretical based on knowledge of how engine manage software works

I think you might have missed a word in your reply. The sentence “Depending on the timing changes, it may actually ?? some.

Did you mean to say that it might actually help some?

 

[HSKR R/T]

I think you might have missed a word in your reply. The sentence “Depending on the timing changes, it may actually ?? some.

Did you mean to say that it might actually help some?

Nope, first sentence said it "shouldn't effect" highway mileage. That was the follow up saying, that depending on timing changes it may actually, some. The referemce to highway mileage effect was inferred. And it could effect it either way