Engine/Transmission (1998.5 - 2002) 13.5mpg Auto?

[WTGillin]

I finally calculated my fuel mileage in my 2001 stock auto. 13. 5 mpg!!! :{

I talked to Cummins Northwest, and they said thats what you get in an automatic. Is this true? I wanted to get a manual in the first place, but had such a hard time finding one. What a mistake!!! If this is the mileage I can expect, this truck is gone. Sorry for the rant.

 

[24V-DSL]

Do you have 4. 10 gears?



Your mileage seems low. My 4. 10 truck when stock, but with 285's (that only lasted a few thousand miles) got ~14. 5 overall. With all my bombs now I'm getting 16-17 overall, and can touch 19 on pure freeway.



Welcome to the TDR.

 

[WTGillin]

I have 3. 55 gears on 265's. I thought it was too low. I think I've noticed it decline since I bought it, the power too. I've had it for 7000 miles now. I'm running B20 and have been religious about my filters and I have a FP gauge. My father suggested adjusting the valves, but I thought that was pretty much a non-issue on the 24V's. Any suggestions?

 

[DirtyDodge]

HI,

I have an 02 auto 4X4 3. 55, Gets 14-15 in town and 17-18 on highway with 285's. Would do better if I had stock tires. Is it running good? Wonder is an injector is not operating correctly? Seems a little low to me.

 

[Brand-X]

My 99 gets 13. 5 to 15 all the time around town went to Fla. last year towing a 69 dart down on a towbar avrage was 19 round trip.

 

[Graphic man]

I finally calculated my fuel mileage in my 2001 stock auto. 13. 5 mpg!!! :{

I talked to Cummins Northwest, and they said thats what you get in an automatic. Is this true? I wanted to get a manual in the first place, but had such a hard time finding one. What a mistake!!! If this is the mileage I can expect, this truck is gone. Sorry for the rant.

on the HWY you should be seeing 18 or so, i would check the map sensor and IAT, any of this will cause poor mpg



Scott

 

[WTGillin]

on the HWY you should be seeing 18 or so, i would check the map sensor and IAT, any of this will cause poor mpg



Scott

What's IAT? And thanks for all the replies guys!

 

[24V-DSL]

Intake Air Temperature



#7 on this:



http://www.dodgeram.org/tech/dsl/mt_2_feb98/fuel_sys_comp.htm

 

[wlowe]

I've kept mileage records since new. My overall average since new is 16. 6 MPG. I average 15-17 around town and 20 on the highway with a high of 21. 6, worst was 9 pulling a fifth wheel through the Sierras. Recently my mileage dropped a couple mpg's so I cleaned the IAT sensor and added some Valvoline synthetic fuel injector cleaner and mpg's are back up again. I don't know how much it helped to clean the IAT because it wasn't very dirty, looked like new. A couple of other possibilities are a boost leak or a slipping convertor/transmission. Good Luck.

 

[Lsfarm]

A few things to check

Your truck should be at 18-1900 rpm at 70mph IF the torque converter is locked up. If the converter is bad and your truck is running in fluid drive all the time, then it will be at around 21-2300 depending on load, up/down hill and winds.



When you are at 70 mph, in OD, rapidly push the OD lockout button twice, this momentarily will unlock the TC then relock it. You should see a ~200rpm jump up then down.



Another thing to check is your front tire wear, if they are badly cupping or feathering, you may have an alignment issue that is eating up HP.

Check tire pressure, for best mileage the higher the better, I runn 60 psi front 50 psi rear, unloaded.



What speeds are you driving?? anything above 65-70mph the mileage will drop rapidly. For best fuel economy 60-65 is best, if you can stand to drive that slow.



Check the air filter for dirt or obstructions [like a mouse nest]. Check to see if the radiator fan will freewheel, if it is stuck it will cost you ~1-2mpg.

Change the engine oil to full synthetic, and the front and rear differential to synthetic gear lube.



My '01 QC 4x4 Longbox with toneau gets 15-16 around town, and 17-18mpg on the highway. On the highway I'm rarely less than 75mph. With the truck and trans stock, the mileage was almost identical. If I'm stuck at 60-65mph, I will see ~20mpg.



You may want to try to find an edge EZ to borrow for a tank or two to see if some timing will help your truck.



I hope some of the above helps.



Greg L, The noise nazi

 

[RPMDodge]

I have an 01 auto 4x4 and i get 18mpg. Do what lsfarm said..... I changed to synthetic everything and help alot... ... . Good luck Rick