Gas Milage
 

My 2001 2500 is only getting 15mpg no matter what i do. Ive got a Edge juice w/ Attitude, its straight piped, it has a 3.55 rear end, and an AFE air intake. All the people i talk to says it should be getting around 20. Any suggestions for what might be wrong.

:humm: :humm:What trans do you have, auto or manual? Tire size? 4x4 or 2wd? Lifted or not? Any squeaks or grinding noises coming from any of the wheels, axels, brakes, bearings? Last fuel filter change?

4 speed auto transmission, 4x4, not lifted, 285/75R16, No squeaks or grinding coming from anywhere and just put a fass platnium 150 on about 17 months ago and they said the filter should be good for around 20,000 miles and ive only put on around 8,000.

Gas mileage???:humm::nope:

Fuel mileage :tu:


The wider tires don't help. Have any problems with the IP? Is the IP stock? Clean air filter? What FP are you seeing from the FASS?

Kinda new to this. IP? Whats the easiest way to check fuel pressure. I just cleaned the air filter not long ago but i think its time for a replacement.

IP-Injection Pump

Get a fuel pressure gauge to check FP. A fuel pressure gauge is a must for these trucks. :c:

Brand new injection pump installed when the fass was put in

The truck is my sig is wearing the same size tires (studded snows, which have a lot of rolling resistance) and gets on average 17 mpg constantly (mixed driving, city / highway, empty and not towing). same ratio in the diffs as you too. I get the best mileage with the edge turned up to 5 but with a mindful right foot. Maybe check your air pressure in tires and verify you don't have dragging brakes or bad binding wheel bearings. Also, how many miles? Could be time for a valve adjustment too if you are up there in the miles.

yeah somethings up. my truck gets 15mpg when i beat it on it and do all city driving. and i have 4.10 gears

Something is wrong. I get 14 MPG at least towing my 31' RV with me. I can usually touch 20-21 MPG with thinking to much with a empty truck.

Now remember anything creating drag will create heat. Like drag brake will make a rotor/drum hot to the touch. Transmission issues will show up in a rise of trans fluid (manual or auto). Same goes for the engine if some thing is wrong the EGT's and coolant temp will rise.

Error Codes?

Fuel Pressure?

So true. More rotational mass and rolling resistance the worse your MPG's. Just changing from 265's to 235's gave me a 2-3 MPG boost.

RV275 Injectors gave me a mild boost as well. Then on top of that I typically ran 5x5 on the Edge Comp but now I'm fighting for a smokeless tune on 5x3 but not as good as 5x5 is.

http://i48.tinypic.com/mmaop3.jpg

My empty run ....

What type of driving are you doing. If this was all around town then this is not really bad. If it is freeway driving then it is a bit low. 16 to 17 is pretty normal for combined city and highway. Over 20 on the highway and around 14 to 15 around town.

Speeds, tires, acceleration, length of trips, extended warm ups etc. I get worse MPG in the winter ( some places also change the blend for the cold weather and it has less BTU also)

Right on money...

Higher the cetane the lower the BTU's...
http://articles.mopar1973man.com/ima...cetane-btu.jpg

Engine Coolant temps and IAT temp play a huge role in MPG's.

Engine coolant is optimal between 190-200*F Just dropping 10*F down to 180*F can have effect.
IAT temp are optimal at 100-140*F for MPG's. The warmer the manifold temp the better the MPG's.

Length of trips... This varies from person to person. Like me anywhere I got I've got a 50-100 mile drive so warm up period typically are short and constant drive speeds. Compared to stop and go travel and driving a short distance and never getting fully warmed up.

Tires... The bigger the tire the more rolling resistance and rotational mass. This why racing slick are smooth face (least amount of rolling resistance) and light weight (reduced rotational mass) to get the maximum amount of power to the ground. So just going from 265's to 285's will reduce MPG by at least 1-2 MPG easy if not more depending on tread face design. (Rolling resistance).

Speed. Wind drag doubles from 55 to 65 MPH so like me 55 MPH is the best of all worlds but 65 MPH is a 5 MPG drop for me. I lose roughly 1 MPG for every 2 MPH over 55 MPH.