+1 on a live tune... i have a leak and still get 8mpg. Magnuson actually claims a small increase when going from n/a to fi.

 

Now if it was only a Magnuson Kit.


Sorry you are having so much trouble, it sounds as though you need to work on the calibration a little. Our 2005 did not get nearly that bad of mileage with the 112 on it.

FYI Fstnblu, the claims of 1/3 of a HP is directed toward the cruising mode of the truck.

 

I made it back to Florida late last night. Thanks for the 3rd gear tip, even thought I was turning 2700-2800 in 3rd my mpg went up from 7 to 10 -10 1/2 mpg. In drive I would pull between 1.5-3 inches of vacuum most of the time(flat roads). In 3rd it was 5-6 inches of vacuum while towing. I guess its enriching the mixture at the lower vacuum reading killing the mileage. Now I just have to get the tune worked out.

 

glad you got it worked out.

 

Thank you. Looking into a dyno tune tomorrow

 

My experience towing a 6000 lb trailer with the Denali over the past 5 years, with a 112 and about 5 lbs of boost.

1. Westers tune, 8 mpg
2. Two bar tune from Campbell Automotive 8 mpg.

Of course, I like to race people off of traffic lights with the trailer attached, just to mess with their minds a bit.

It is worth it to me though for the extra merging/passing/hill climbing power.

For reference, only get around 12 mpg driving around town and about 16mpg on highway without trailer. Always have noted the loss of half of mpg when towing on highway.

Or whatever the metric 22L/100km city and 33l/100km highway when towing converts too.

Makes me lust for a duramax in my denali.....

 

This behavior is encouraged.