I recently went on a road trip from Eastern West Virginia to Detroit, Michigan to visit my sister. I pulled out of the driveway with almost a full tank. The trip was approximately 500 miles (all highway) one way.

MY concern is the fact that I am only getting barely 15MPG. I roughly travled about 430 miles before I had to fill up. I took the miles traveled on the trip odometer and divided the two, and it kept coming up with approx 14.92. I recently got my VP 44 and my lift pump replaced under warrenty (they put the intank LP in much to my dismay). Shoot I was getting better mileage before I had toe VP/LP problems.

Some things that I think maybe running against me is the fact that I have a 4:10 rear, and am pretty much stock except for air box, exhaust, and some bling bling.

A couple buddies of mine suggested that maybe my truck is not even broke in yet.

The truck only has 49,000 miles on it.

Has anyone else experiencec this with a 2001.5 or is it just me?

Thanks guys.

 

I have a 2001 Dodge 2500 4x4, with 3.73 rear and I get around 18 and 19 mpg
running around 70 to 75 mph. So I think that if you change out to 3.73 it would

 

Ditto here to, get a little over 20mpg if I stay at about 1800 to 1900 rpms

 

they dont make 3.73's for the 2nd gens.

dad has 4.10s in his truck, and his best mpg is 16 or 17.

my truck as 3.55's and my best is 19 or 20.

 

Sorry, its been a while sense I have really check it out, but I guess you learn something new everyday.

 

I get between 17 and 20 mpg if i go easy. Check the tire pressure this will make the biggest difference in your mileage i would stay at about 65 psi cold with 10 ply tires. Other than that just keep your foot out of it and you should get at leas 18

 

Your 4.10's are killing you! Mine gets about 16 doing 75 on the highway too.
You need to stay at about 65mph for over 20mpg. That's hard to do though.

 

i am just like you with my 315s i get barly 15 mpg i cant figure out what is wrong oh also i have the 3.55 gears

 

Yea i got the 4.10 gears and am getting 16-17. When i put the 315/75 Pro comps on it didnt really change me any. I guess it was a trade off between more heavy tire and less rpm's at highway speed.

my truck is stock too except for the muffler and cat is cut out

 

If you put on taller tire than stock it will throw off you speedometer, you are going farther than your trip gauge thinks. I don't know how much, but it would be more. I guess you could measure around a stock tire, them what your running, and do the math and see, OR take a smarty and recalabrate your speedo for the larger tires

 

I'm running 235's (instead of the stock 215s) which gives me a correction factor of ~.04%.
I also have the 4.10 gear.
With the cruise control set to 64mph (~2100 rpm ) I have achieved an honest hand calculated 20.5 mpg.
'Normal' is ~18 mpg hwy.

 

I've read several posting that said the new ULSD has reduced mileage.

 

I have similar set up except I have 3.55s. Running 285 Pro Comp ATs. Went to KC from STL a few weeks ago 19.5 MPG going & 20.5 coming back running 72 MPH @ 1900 RPMs. Calcs are based on GPS mileage.

 

shovelhead how do you do that calculation for oversize tires

 

first road trip with the 12v- 18.25mpg w/cruise set at 77 with 2 100mph passing zones... It was on a 300 mile trip hand calculated.

edit- 3.54 gears