WaywardSon

I bought this truck in mid-June and have to say that I have been pretty disappointed in the fuel economy. The truck is an '05 2500 4X4 auto tranny and is getting 12 mpg on mostly short trips around town. On a 1400 mile trip she averaged 16-17 mpg...best was 19 on one tank.

I recently replaced both the air & fuel filters (Baldwin)...don't use any fuel additive until winter and have a very light foot.

The one difference I have noticed from the truck it replaced ('01 Cummins, auto, 2WD that averaged about 16) is that when this '05 is under more than even moderate acceleration, it puts out a lot of black smoke.

Any thoughts?

saggonwaggon91

What mods are on your truck? What options does your truck have? I had an 05, 2500, 4x4, crew cab, short bed that was completly stock and could hardly ever get it to smoke. I did notice that as the more miles was put on, the better the fuel mileage it got. The best it got on long trips was 23mpg and around town was closer to 16mpg. The best I get with my current 05 is 17.5 on long trips but it has 3.73 rears vs. the 3.55's my 2500 had.

WaywardSon

Truck is bone stock as far as I know. It is a crew cab, short bed with a tonneau cover and has about 83,000 miles. No idea what the rear gear ratio is. I run a bit over 70 at 2000 rpm.

I left W. KY this morning for Memphis running down I-55 which is about as flat and straight as it gets. I reset the odometer and computer when I fueled up at Charleston, MO.....computer said 22.5 mpg when I shut it off. We will see...

steelblitzkrieg

Probably chipped/programmed. When you're showing that high on the display it's usually due to the fueling mods. I would see 23+ on mine when she was chipped, now unchipped I rarely see it above 19-20 and I get great hand-calc economy.

Danderson

Make sure nobody's behind you and after warming the truck up,go for some pedal to the metal high rpm runs.
If the truck has been driven for fuel economy the cat could be sooted out.
I baby mine a bit and use this procedure to clean up the exhaust system.
A Dodge tech of decades on the TDR recommended it.
It's worth a try.

WaywardSon

When I was a kid that was called an Italian tune-up:-)

Yes......worth a try for sure.

saggonwaggon91

I would say with it being just over 70 at 2000, you have 3.55s. You cant trust the overhead display, hand calculate your fuel mileage. Mine will say I get 26mpg then actual comes in closer to 17 when done by hand. Like stated previously, take it out and run the crap out of it, get it good and hot. If you have a trailer you can load, use it. I had an old JD 830 that would slober fuel out the exhaust if it wasnt worked hard.

WaywardSon

I view the overhead display as an amusement center...and hand calculate every tank. I will be running back North on I-55 tomorrow and will fill up at the same Flying J in Charleston, MO as I did coming down. Not sure if Mama will stand for the Italian tune up routine on her watch:-)

**** the price of diesel on this trip. Arkansas and Missouri have both been higher than Kentucky...haven't thought to check in Tennessee.

At any rate, I will have some answers by tomorrow night. I reset everything and will hand calculate at tomorrow afternoons fill-up. The computer is currently showing 20.9 after a day in downtown Memphis. But the wife is happy. Now off to dinner.....

WaywardSon

Not what I had hoped for, but better than a poke in the eye with a sharp stick. When I got home the computer said 21.9.............after filling up, the hand calc said 18.2 mpg

I won't get any better than that...cruise on 72 & a flat straight road. Oh well.......

Thanks to all for your comments.

Danderson

FYI,our 2005 Honda Pilot averages 17-19 mpg. You're doing fine.

WaywardSon

Yep....it's all relative, eh? I'm OK with it, just like to whine I guess To be honest, no more than I drive it doesn't make a whole lot of difference. My fuel bill probably averages less than $100 a month.

ConstantSorrow

Stumble is gone and thank you all for the advise. However my fuel millage is still poor. I’ve replaced the FCA, pressure relive, fuel filter, and the air filter. I have removed the cat and the muffler. Only getting 13 on the freeway and 9mpg towing a trailer weighing around 6500lbs. Just living with it is not really acceptable. Any suggestions?