Increase milage in a Duramax?

[TPCDrafting]

A friend has a '00 Duramax/Allison 4x4 and was looking to find a way to pick up 2-6 MPG. What is available to accomplish this?

I was thinking of the following:

1. K&N or some other aftermarket air filter

2. Free(er) flowing exhaust

3. Edge box

4. ????

What have you tried and what works? TIA



I don't know anything about Duralaxes, so I posted this for him on GM-Diesel.com on Jan. 1 and have not had one responce yet. Go figure





So anyway I decided to post it here where I know I will get some sort of responce (even if it's bad mouthing ) He used to drive a '91 Dodge/Cummins and was a TDR member for years, so he's a good guy, just came accross a deal too hard to pass up on this truck. He's real happy with the power, just would like to pick up some mileage as he drives a lot of miles.

 

[LSMITH]

My uncle said he got a lot more power by getting rid of the muffler and going to a free-flow type on his 01 Dmax. He did not mention any MPG gains, but if power went up and that is the only mod then it should help some. The guys over on the dieselpage are using some sort of AFE induction system and really are liking it. Doubt it will help economy though. Edge timing changes might help, might not though too. $800 is a lot to get 1-2 mpg IF you get that, just like the EZ on our trucks is a horrible investment for fuel economy gains alone.



One thing that WILL help, by 1 MPG or so average and maybe up to 2 MPG this time of year is good synthetics in ALL the gearboxes. I used Mobil 1 75w-90 in both axles. I used Mobil 1 5w-30 in the T-case, but if he is under warranty Mobil makes a good synthetic ATF too. Unless he is not scared of extended drains the cost of synthetic oil in the crank case would eat a full 2 MPG worth of gain and maybe more, and he will not see anywhere close to that from just the engine.



Hope this helps.

 

[lmills]

Heck lost fuel mileage when I put my EZ on. I even pampered it to try to see if I was running it too hard. Of course I did put it on right when the cold temperature hit

 

[Mike Ellis]

I don't see how he could pick up much mileage by power mods, the Duramax is already pretty stout. The engine has quite a bit of power, so perhaps an overdrive unit like the US Gear or Gear Vendors would help him reach the goal... .



Easiest way to pick up mpg is to reduce speed 5mph or so. . !

 

[LSMITH]

Originally posted by lmills

Heck lost fuel mileage when I put my EZ on. I even pampered it to try to see if I was running it too hard. Of course I did put it on right when the cold temperature hit

Don't feel like the lone ranger, I put nearly 30K miles on an EZ and lost fuel economy on every one. It may not be the cold

 

[lmills]

I can deal with a little less mileage as long as the power keeps a on my face

 

[nickleinonen]

propane injection will help... a bit. .

 

[Alan Reagan]

With fuel mods like the EZ, VA and Raptor, you should be able to pick up mpg increases. I have with both the VA and Raptor. The timing is optimized with those boxes and with reasonable driving I've seen increases of about 1. 5 mpg using them.

 

[LSMITH]

Alan, I did gain some fuel economy with the VA, but not the EZ. I am running the VA again.