I have the Eagle LS tires on them. Max PSI is 44. I aired them up this morning before driving to 39 in the front and 38 in the rear. I still have the drift to the right, so I think I just going to take it in and have the alignment checked. The 20's seem to ride pretty rough. I had a '01 QC 5.9L with the 17's and it was a much smoother ride. I may change out the shocks to try and "soften" it. Thanks for the help.

Oh, and over the last 2 days, mileage is running 11.7-12.9 in the city....so it has come down some.

Paul

 

Guy's your tire inflation psi on the sidewalk is a raw number for max inflation...you should always use the manufactuers specs. usually located on the driver door striker post or owners manual. This is a major deal and was probably part of the problem Firestone had on the Ford Explorers. People always just look at the tire sidewalk to get inflation info...but the maufactuers spec is what you should use.

 

Door jam shows 36psi with 17's....would it be the same for 20's? I have backed it off back to 36psi front and 35 rear.

 

2003 ram 1500 4x4 5.7 Hemi. 15MPG city 22.5 hyway.

[IMG]local://upfiles/17499/A8FF55333B0D40D89162E044533BFDC4.jpg[/IMG]

 

2003 ram 1500 4x4 5.7 Hemi. 15MPG city 22.5 hyway.

[IMG]local://upfiles/17499/A8FF55333B0D40D89162E044533BFDC4.jpg[/IMG]

 

only 400 miles on her but she's gettin city/highway average of 15.4 mostly city driving on 20's

 

'04 QC 4X4 - I get in the 12mpg range.

Looking at adding an AEM Brute Force air intake and a PowerAid Throttle Body Spacer. Some reviews say about a 1mpg increase in fuel economy, others say don't waste your money. About $350 for both add ons.

Anyone got any opinions?

 

Just did a 1000mile trip from Maine to Ft. Benning and I averaged 17 MPG @ 70MPH in my diesel. I was getting 20.5MPG at 50MPH because the turbo doesn't really spool up until 2K rpm. My truck only has a 2" leveling kit up front, and I think a non-stock exhaust (3.73 gears).
I bought used from a GMC dealer and the previous owner had a cut-out on it. This is illegal with Maine inspections, so they put a new exhaust section on it but since the duramax doesn't have a cat (I guess) they didn't put one back on mine, free performance upgrade.

I'm looking at a mild performance chip to increase MPG, as well as HP and TQ. I'll add it on here when I can afford it.

 

sounds about average Shaun. I get about what you do even with my 4.10's. try some Power Service, 16 oz per tank and you'll see your mileage increase. and it will also lube the pump and keep the injectors cleaner.

I'm testing 16oz of PS and 8 oz of Marvals Mystery oil per tank with some so far impressive results. still too early to tell but thus far Ive gained about 2.5mpg

 

Cool, thanks for the info. I read that in your post earlier and I'm looking at trying that, I think I actually looked at PS at Wal-Mart yesterday (or something similar). I'll go grab some tonight and throw it in. Do you or anyone else know of free or almost free MPG increases besides a light foot? I can't wait till I need new tires so I can go larger and try to get a few more MPG.