Engine/Transmission (1998.5 - 2002) Help! 12.6 Mpg!!!

[MWilt]

i have cleaned the MAP and the IAT. Checked and tighten the intercooler hoses. Truck starts right up so i don't think its a fuel pump problem. The truck only has 14000 miles on it and this is my first CTD i was all excited to get good fuel milage and now im really dissapointed! Please my checkbook can't take much more of this!

 

[bmoeller]

Is your truck a 3/4T or a 1T? Has it always been that low? What is it like in the summer?



With that low of mileage, your motor probably isn't broken in yet.



If you have 4. 10 gears, it will make it worse. Winter fuel hurts mileage. Anywhere from 1-3mpg. Having to warm up the engine longer in the cold weather won't help you. When it sits and idles, it gets 0mpg. My last tank had a lot of run time sitting still. Only got 12. 4mpg. Normally get 14+ in winter if I keep to a minimum.

 

[MWilt]

Its a 3/4 and i just bought it in December 21. It has the 3. 54 i think 1600RPMs @ 55. I try not to let it idle to long because of wash, I was hoping to get around 15-16 because i knew it should come up a few numbers in the summer. And being stock doesn't help, i need a EZ.

 

[jjohn]

https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=80209

https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=80209

 

[woodsrat]

mileage

need an EZ, bomb bug gets another one. LOL

is you mileage around town?? check mine the other day and was down to 12. 4 but that was in town spinning around in the snow, jump up on the big road and took a little road trip jumped back up to 14. 6 and i have 4. 10s.

 

[2ndgen2500]

who ever says 4. 10s are worse, im not sure why, in town i get much better mialage than anyone i know with 3. 53s, and i just got back from a 500 mile trip, un loaded, and averaged 20. 9 mpg with the mods below. and a loaded trip gvw 15,500 and avearged 17. 9, i love the 4. 10s, and i got better mialge after the mods... .



to anwer your quesiton, i dont think your truck is broken in, you should easily see 15mpg by 25k or better imho...

 

[R-N-R]

I started out with 7mpg, jumped to 10 around 5k miles, then 12 and now if I keep my foot out of it I will see 17mpg. I did not get over 15 until about 20k miles. I get around 11mpg (summer) towing a 6k lbs TT. The best advise that I received and will pass along is to find the heaviest thing you can, like a backhoe on a trailer, and pull it like there is no tomorrow. One good long day trip should help you out. These trucks love to carry/pull a load!

 

[Devildog]

I get around 12. 5 - 13 mpg, I don't think I ever saw 15

 

[JR2]

12. 5 is about what I get all winter long...



I have saved all my records for fuel purchases/milage etc and at the end of two years I averaged 15 mpg. 12. 5 is decent winter mileage.

 

[856.9]

I got my truck with 14k in June. I averaged 18+ with a mix of freeway and city driving. I was stoked. Babying it I could barely hold 19. Made a trip to Oregon, and I got worse milelage cruising at 75. approx. 16mpg. Once the bad weather hit around november I put on a set of 285 mudders and my milage dropped to 14-15 for my normal, city/freeway driving. The trip computer seems to be about 1. 5mpg less than actual with the bigger tires.

 

[2ndgen2500]

my computer is also 1. 1 mpg lower than actual.

 

[mcoleman]

My last fillup was 18. 873 mpg with 3. 54 gears. I usually stay above 20 mpg in the summer. I drive 35 miles to work and 35 back home everyday so most of my driving can be considered highway although I have alot of hills around my house. Staying under 72 mph is the secret to good mpg on my truck. Anything over 2100 rpm will cost me in mileage.

 

[Houser]

o2 Milage

Houser here

I have an 02 HO with an EZ chip and get 18/19 winter HWY driving The EZ gave 1-2 mpg improvement over stock. It has to be on the Hwy about 10 mile to get warmed up to good milage.

 

[KIseminger]

When I first got my 02 2500 I was getting about 15-16. After it broke in I was averaging about 16-17 and was driving on city/hwy/mountains. The best I ever got was 20-21 on the hwy going 65 in Minnesota. Just before winter I put 285/75/16 AT's on on I dropped about 2MPG (a more aggressive tread does not help). And lately I have been struggeling to keep up with 13-14 around town. I know it's frustrating, but you just have to do what you can. And like Houser said, it taked a while for these things to warm up. I have learnd that there are a lot of variables, but here are some suggestions that might help.



-Use a chip (already been addressed)

-Get 4" exhaust (this will increase performance and mileage and lower you EGT's)

-Use synthetic oil such as AMSOIL in your engine and all gear boxes. These oils are much slippier than conventionals and will not thicken up as much. You can even go to a lower viscosity (i. e. 5W-30 in your engine) all year round.

-Diesel Power Products makes a item called Turbo Air Guide. http://www.dieselpowerproducts.com/tag

I have one in mine. The effects are suttle but I picked up about . 5-1 MPG



Good luck

-Kyle