Fuel Mileage Update(New 2002)

[Bratton]

Hi all,

I'm the one who had the recent fuel mileage thread going as I was alarmed at the low MPG's I was seeing on my new 2002. I just went on a 4000 mile trip from Bozeman,MT to Moab, through Vegas, San Diego, to San Francisco, through Reno and finally back home yesterday. Had about 2500 lbs of trailer and another 1000 lbs of gear. The best mileage I saw was 15MPG, which we got on the San Diego to San Francisco leg and the worst was 11. 79MPG going from Salt Lake City to Butte,MT on the way home.

In California they have a 55MPH limit on Trucks and Autos with trailers so I ran about 63MPH while just about everywhere else I ran about 83MPH.



I was kind of hoping to see some major improvement in MPGs on the trip but didn't. When did everyone else see their MPGs improve? I now have almost 5000 miles on the odometer.



Minus trailer and gear I would think the 15MPG experienced in California would have been closer to 18MPG. I'm wondering if those reporting the high MPGs are running at slow highway speeds. BD

 

[JR2]

It sounds a little low but your engine has not broken in yet. You need at least 10K and if you don't tow something heavy 15K to break in the engine.



I have a 2001 and the best I ever got was 19 mpg, that was all highway. After the first year I owned the truck I added up all the #'s and if I remember correctly I averaged only 13 mpg for the year. Give it some time, besides if it was a gasser you would be getting 8 all the time

 

[Mark_Kendrick]

The high MPG reports are from 12Vs and ETC's. Auto's seem to get good mileage for some reason



Change your thermostat to a 180* from cummins(The part # for it is 3954194) and get a BHAF (fleetguard# AH19037). Both help mileage a bit.



Injectors and a box help a lot for HO's if you can keep your foot off the firewall I can't



My stock 2001 ETH/DEE 4x4 QC 3500 got 15-16 pretty consistantly ay 70+ mph. Below 65 I get 17-19 but I can't keep the speed down for that long



With the current mods (DD3s, PE Comp, BHAF, 4"ex, B1, 180* ts) I get 16 or so at 75-80mph.



The best mileage increase lately was the 180* ts . . got . 5mpg better immediately w/no other changes.



FWIW,

Mark

 

[1tuffram]

T-stat

What temp rating are the stock thermostats?

 

[Mark_Kendrick]

190* is stock

 

[andrewkoperdak]

I live in San Diego. Empty I get about 22 MPG. I also pull a 6500 pound 5th whl. When I do the trailer I get 15. 5 MPG. I have a standard output 5. 9 with a 5 spd and 3. 55 rear.

 

[Agades]

Originally posted by Bratton

Hi all,



youre not alone

my new 02 isnt getting good mileage either (13-15empty mpg)

at least not as good as my 99 did when it was new:{

 

[Bill_L]

I hope that my mileage starts to go up as I get miles on my truck or start to bomb.

I only have like 2k on the truck so far and have been getting about 11mpg average.



I know that my Comp and DDIIs will be in somewhere in the next 1k miles. I guess we will see what that does.



Bill

 

[SmokinJoe]

Originally posted by AKoperdak

I live in San Diego. Empty I get about 22 MPG. I also pull a 6500 pound 5th whl. When I do the trailer I get 15. 5 MPG. I have a standard output 5. 9 with a 5 spd and 3. 55 rear.

Your truck must be running right! Are you a SWB or LWB Quadcab?



The best I have got to date was 19. 99 with out the Pacbrake. and that was in town. When my dad drives it for a 300 mile trip he only gets 17. 5 mpg at 65 mph and 1000lbs of packages in the back.



I will be installing my gauges soon so I know if my lift pump died and I have a replacement AIT sensor from Cummins to install.



It is NOT very flat around here, but I would not say we are in the mountians in Michigan...

 

[Royk]

I just filled up yesterday and did the math as usual. I was surprised that my mileage went up exactly 1 mpg to 19. 0 mpg. I had been getting 17. 5 to 18. 0 up to now. I just so happens that this last tank was filled at 4,981 miles and it was what I was running on when my odometer rolled over to 5,000 miles. I've heard that a new truck's computer "learns" how you drive for a few thousand miles and adjusts for certain things. I wonder if this had anything to do with it. According to my fuel station they're still pumping winter mix, so that isn't it. Also I did a lot of stop-and-go on that tank and less highway driving, so if anything, my mileage should have gone down.



-Roy

 

[LarryG]

I have the 24 V, 2002 quad cab with a 4:10 rear and auto. Initially I was a little disappointed, getting in the 16's. With just over 7K, I'm getting almost 17 city and up to 18. 4 highway empty. I watch the mileage meter and drive accordingly (most of the time). I'll be very happy if I end up with 18 overall one day. I got the diesel 'cause I couldn't bear the thought of getting 8 mpg everytime I started it up. I can't justify it economically - it took me 11 years to put 152K on my last vehicle, so it has to be put in the toy classification. Besides, when the Arabs shut down the pipeline just cause they like us even less, I'll be burning corn oil from America's Heartland!

 

[andrewkoperdak]

Originally posted by Smokin Joe





Your truck must be running right! Are you a SWB or LWB Quadcab?



The best I have got to date was 19. 99 with out the Pacbrake. and that was in town. When my dad drives it for a 300 mile trip he only gets 17. 5 mpg at 65 mph and 1000lbs of packages in the back.



I will be installing my gauges soon so I know if my lift pump died and I have a replacement AIT sensor from Cummins to install.



It is NOT very flat around here, but I would not say we are in the mountians in Michigan...

Smokin Joe,

I have a std cab with 8 ft bed. I too live in hilly/mountainous reginon of the SW US. I have wonderful hills that are 6% grade for 15 miles and more. My MPG usually dips to 10 MPG on these grades. My worst mileage (per tank) was 17. 4 MPG. I think one of the biggest reasons I get better mileage consistantly is that my weather is significantly warmer than most others. I only saw freezing temps 3 or 4 times this past winter. When the road is flat like in south central CA I crusie at 69 MPH and get consistant 22 MPG

 

[FDNYMOPARGUY]

I have a 2002 2500 QC SB H. O. 6sp 4X4 3. 55 with normal wieght of 7400 lbs. including tools, cap, gear. I drive about 75% highway/25% "around town". When new (12/01) was getting mid 16s MPG. Now, at just over 7000 miles, I'm getting low 19s MPG most of the time. When towing(6500 lb TT), hauling firewood, or pulling stumps, MPGs go down to around 15.

 

[Lsfarm]

Two Items

First, everyone who posts MPG numbers really needs to state if these are hand calculated or read off of the trip computer. My actual mileage dropped after I started to add horsepower, because I can't [really: I JUST CAN'T ] stop mashing the pedal.

BUT the trip computer keeps telling me I have gained 3-5 MPG. And the trip computer was 1-2 MPG high when I was stock.



The other item, for you folks with 2002 4x4 trucks, you will probably get poorer mileage due to the front axle disconnect being removed. Your truck is pushing the entire axle and transfer case geartrain all the time. this may not seem like much, but it used to be worth 1-2 MPG on the trucks I had in the 70's. I alway knew if I had forgotten to unlock the front hubs.



My mileage drops significantly once I exceed 68 mph. I think the truck aerodynamics get pretty 'draggy' above this speed.



Greg L

 

[FDNYMOPARGUY]

All my calculations are done by hand at each fill-up. Miles driven divided by gallons used. I always top off the tank. I keep a fuel log as well as a maintenance log as one affects the other.

 

[Rockcrusher]

My 2002 quad cab long bed, 4 sd auto is only ave 13 mpg. A real dissappointment after getting 18-20 on my old '90.

I'm not a lead foot(most of the time). Pulling the trailer I

 

[D6Diesel]

19. 8 mpg calculated at the pump. Mix of highway and city driving. Also, I use fuel additive.

 

[Chipstien]

Last 9 tankfuls are as follows....

13. 942

15. 107

15. 575

16. 404

11. 778

14. 201

13. 693

13. 638

and most recent... 14. 188

The oversized tires have been taken into consideration in these calcs. (hand calculated of course) 90% of my driving is stop and go city driving with a terrible habit of leaving a dark cloud of toxic gases at every intersection.