Norm, You know as well as I that the .2 seconds of shift time every few miles doesn't burn 2mpg worth of gas. Unless you're riding down the interstate rapidly pushing the o/d button.

 

Chester - I HAVE to "call" you on this. I know how to calculate gas mileage. I know my speed and odometer are correct. At 68 1/2 years of age (*I'm really old*), I know when I alter my driving habits and when I don't.

My mileage DID improve after I installed the Edge, and it improved even more (about 1/2 mpg) when I converted it to a Gryphon with custom tunes.

One possible explanation is that tuners can lean out the mixture a bit above stoich as long as you are not under load (in a highway cruise condition). Over many miles, this can add up.

And, if they can set the A/F ratios to be optimum for efficiency in open loop, you get further gains.

- Jack

 

Ok, I'll give you that. It can improve your WOT gas mileage.

1/2 mpg more means you went about 10 extra miles on a tank. Assuming 15mpg baseline, and a 20 gal fillup. That's VERY narrow measurement margins IMO.

That would be an impossible margin for me. I probably have about 10 miles of burnout on any given tank.

 

I'm curious if these mileage claims are combined city and highway or just highway. I do a lot of city driving and while you do use less pedal effort than without a tuner, I either drive too much city driving to notice much difference. I don't gain much mileage with the stop and go of in-town driving. I just made a 400 mile road trip and averaged 18.5 on the highway (SCrew, 4x4, 3.73s), which isn't bad considering my truck was rated for 17 highway. This was using a performance tune. I just have a hard time believing running in closed loop on the highway makes that much difference, stock or tuned. I don't have a basis of comparison, as I put tunes on this truck in the first month I owned it. Can some of you clarify the mileage gains of 2 mpg?

 

There is more to it than that. Believe what you like. Many people here will disagree with you. The proof is in the pudding as they say. Personally I did not buy my tuner for MPGs but some people do.

 

Nicely asked!

MY mileage gains are ALL highway driving. I only drive my truck in the city far enough to fill the tank with gas (or if I have to do some kind of major "hauling").

Before I got my custom 87 non-towing tune, I could get between 15.0 and 15.5 driving at 55-60 mph. (We take 120 mile trips to a place in southern Arizona that is all "country road" driving and that's the average speed. If I was driving 70-75 on the interstate, the economy dropped to about 14.5 mpg most of the time.

With the tune though, I'm averaging 15.5 at 70-75 mph. And on the country road trips, we get 16 - 16.5 mpg.

I normally fill the tank when I reach about 23-25 gallons used.

I also posted a long time ago that I picked up at least 0.5 mpg while towing, with the towing tune, and this was over a 2,400 mile trip up into the Colorado Rockies. (Total distance / Total fuel burned).

I'm absolutely convinced the tuning has helped with fuel economy!

- Jack