Performance chips & fuel economy?

[Jim Cobler]

I must be a little unusual because I am satisfied with the power of my Duramax but would like to know if anyone has done a serious study of fuel economy with chipped engines.

Since most people who put chips in probably tend to drive faster and a little heavier on the acceleration, I am not sure fuel economy has been studied.

If someone has driven 70 or less and examine fuel economy with their chips, I would very much like to know what your results have been.

Thank you,

[More Power]

Fuel economy differences between stock and "chipped" is probably one of the least understood aspects.

The only fuel conomy evaluation I've done is running 600 miles with our travel-trailer with a BS-EZ Amp (90 hp Edge Juice) installed and then 600 miles without it (out & back). I saw a 1/2-mpg increase with the module in use. I attribute this largely to the fact that engine/trans did not need to downshift when pulling grades when running with the added power. There were four fairly significant grades on each leg of the 600 miles.

MP

[rickdlance]

I currently own 3 Edge modules, a Quadzilla, and a Bully Dog Power Pup. I have owned the Duramaximizer, the Predator, and the Hypertech in the past. I have tried exhausts, air filters, air box modifications, ram air, and air intakes also.The first thing I need to know is are we talking the LLY or the LB7. Every thing I do to the LB7 seams to help. The LLY only seams to benefit when loaded. I have put a total of 453,000 miles on 5 Duramax's, and have tried a little bit of everything. I will be more than happy to share what I have learned if you need it.

[Jim Cobler]

I have a 2001 Duramax and I am not sure of the engine number and my interest is, of course, fuel economy. For the record, I always use a smooth moderate start and usually drive around 60 to 65.

Thanks,

[OC_DMAX]

I have noticed about a 1/2 mpg increase when running the Edge Juice/Attitude (level 0) and the TTS economy setting; both of these settings change only injection timing, no extra fuel. I have run these combos on a dyno also, and recorded an increase of about 25 hp (at higher RPM, less at lower RPM). So if one gets more HP by advancing the injection timing without adding any extra fuel, then you would expect the mileage to increase slightly. This is exactly what I have noticed.

[rickdlance]

I agree with OC_DMAX . On the 2001 you have the LB7. I would run the juice w/Attitude on setting 0 or 1, and an air cleaner kit. Most people on here frown on the air cleaner kit, but I have the K&N's on everything. They help more than a 4" exhaust. I have an exhaust for sale if you are interested. My 2001 2500hd 4x4 extended cab and my 2001 3500 drw regular cab 4x4 both got an average of 18-19 mpg empty at 75 mph, and a best of 22 & 23. Towing an enclosed race car trailer with a gross vehicle weight of around 20,000 pounds I would get around 12-13 mpg at 75 mph. The only thing that really hurt my fuel mileage was a strong head wind. These trucks seam to be more sensitive to wind then they are weight.
Whatever you decide to do, Enjoy. I beleive the 2001 was the best year for the Duramax.

[Kennedy]

I generally avoid commenting on this subject as I tend to upset people when I reply about economy, but I'll do it anyhow.

Modify for power and take any economy gains as a bonus. Lots of mfr's claim mpg to sell product, but most never see an appreciable gain.

If mpg is all you want, keep your money to buyt fuel or better yet fuel treatment. If you still insist on chipping for mpg, look for the units that people most complain about for timing rattle...