Engine/Transmission (1998.5 - 2002) 2002 owners w/4x4 non-axle disconnect--what mpg?

[geusterman]

2002 Rammers--we been working over mpg on another string and I have been miseratin' about my mpg (about 14) no matter what the mods were. I have 12K on an April 2002 mfg date truck with no front axle disconnect. As we were blasting through about 6 pages on the string I noticed some other guys with same truck getting not-so-good mileage. I am hoping it is not a defective VP44 but something retarded like this primitive front axle we have. How about jumping in here? George Eusterman

 

[athompson]

When it is really hot or really cold here I usually get between 15. 5 and 16. 5 commuting to work. During the few weeks that it is between 60 and 90 I usually get between 17 and 18 commuting to work.



The best I've gotten was 19 (cruise was set at 75mph). I filled up 2 days before I drove to Provo and filled up again the day after I got there. 475 miles total, so about 75 miles of that was commuting.



Besides the temperature, the quality of the fuel seems to have the next biggest affect on my mileage.



My driving style is pretty consistent. I rarely shift past 1500 rpm. I drive at the lowest rpm that doesn't lug the engine at the speed I'm going. Sometimes this is at or slightly above idle (4th gear in school zones). Many times this is at 1250 rpm (6th gear at 35mph). Sometimes that is at just under 2000 rpm (6th gear at 75mph). And I always downshift as I slow down.



By the way, mine was built in May 2002. And it has about 14000 miles.

 

[rfcom]

Mileage

Combined city/hwy driving in summertime, I get 21 mpg (17. 5 US mpg). Steady cruising at 100 kph gets me 25 mpg (20. 8 US mpg). Winter fuel costs about 1 mpg. It hasn't changed much since new, so at 26000 km. maybe it's not broke in yet.



Jim

 

[geusterman]

rfcom,

Please tell me if you have a front axle disconnect. Great mileage you have!

 

[dslmacdown]

I have a early '02 (build date 10/01) with the front axle disconnect. My mileage runs about 16-17 in town and over 20 highway, highest has been 22 mpg with about 12,000 mi.



MAC

 

[rfcom]

Hmmm... ... I thought all the 4x4s were the same. Now I have to show my ignorance and ask - how do you tell if you have a front axle disconnect? I think my build date is Feb. 02.



Jim

 

[KL]

My truck was built in February 2002 and it doesn't have the front axle disconnect either. I think that any trucks build after January 4, 2002 did not come with the front axle disconnect.



I don't know how much this helped mileage. I have heard up to 1-2 mpg tops, but I have no idea if this is true. But it has to be something, since all the front end parts were not turning there has to be reduced friction.



Even a 1mpg decrease could add up to hundreds of extra gallons of fuel consumed over the life of a vehicle. At a average of 16 mpg, you would use 6,250 gallons to travel 100,000 miles. A 1 mpg drop to 15 mpg would result in 6666 gallons being utilized to travel 100,000 miles.



Its frustrating to hear car makers say they are doing everything they can to improve mpg and then they remove a device known to save mpg. Chrysler knows that it saves mileage. It even says so on page 3-31 of the 2002 Service Manual. " When the two shafts are disengaged, the load on the engine is reduced, thereby providing better fuel economy and road handling. " KL

 

[jrandol]

I hadnt heard about this. Is their a way to tell if you have it or not? Mine is a May or June 02 truck, cant remember off the top of my head.



I have gotten as good as 22 mpg with my truck and as low as 14. 6. My average looks to be sitting at around 17. 9 or low 18's. I have 34,000 miles on my truck and bought it new Aug. 28, 2002.

 

[KL]

Based on your trucks build date it would not have it. KL

 

[Jeff Knight]

I get between 16-18 with 4. 10's

 

[RowJ]

18 around town (50% highway). 21 hwy. No disconect. No towing but average 1500 lbs in bed 80% of the time.

 

[geusterman]

Well, so much for my theory about the non-disconnect front end causing low mpg (mine about 14 mpg). Thought I was on to something there. Kinda like buying a rifle. One groups tight and the next identicle model is all over the place. Which means that there is something in factory setup that affects mpg. I mean to find that. Thanks for your responses. I know it is not real "scientific" but it parallels other responses on the TDR over time and confirms suspicion about the variances in setup. George Eusterman

 

[NETim]

My 3500 averages about 16. 5 unloaded. It did get 20. 2 once but I think that was a fluke. At 75 freeway cruising it drops to about 14-15.



With the Lance loaded it appears that 12 is going to be the average.



FWIW, the non-disconnect front axle can be quickly recognized by the rubber vent line coming off the differential cover.



Tim

 

[schu777]

Mine was built in Mexico - could that also be part of it? Don't know, but every thread about being built somewhere is "Mexico is better built"... anyway, I'm getting 18mpg this summer average of 40/60 of city/highway mileage. If I take a trip down the interstate cruising a nice 60-65 mph, I'll manage to get over 20mpg - I think the best I've ever got was 21. 3 - I do know that the more go pedal you push on, the lower the numbers, if I tend to tromp on it, then my mileage goes down, but if I take my time on the highway, speed up down the hills and let the extra speed bleed off uphill - I'll do much better. I also agree with the fuel - one time I filled up (I always fill up at flying j) and I was pulling a small trailer, head wind, cruising 65 to 75mph and was getting 13mpg... the lowest I ever got, but figured it was wind, but coming home I had a tail wind and still didn't get much better, so I figured it was fuel not as good as what I've had before... at least that is what I think.



Either way, I still love the truck and not planning on getting rid of it, in fact, I plan on having it for another 20 years!

 

[Phil Stuart]

mpg question

No axle disconnect here and best was about 19 hwy before 275"s.



now i'm getting about 20-21 hwy with 275"s



Phil

 

[geusterman]

NETim, yours approximates mine but Schuu777 has one of those "special" trucks (mine is Mexican, April 02 as well). There HAS to be something we can do to "dial in" the CTD a little better. Somewhere is a high tech guru that understands the fuel/air setups and whether they are manipulatable. George

 

[abranz]

poor mileage

I have an 02 2500 quad 4X4 non disconnect front end and the mileage has been very poor compared to what I read others with first gen or second gen. trucks get.

Until two months ago it was between 14-16. Brought it to the dealer (Dave Smith-Kellogg, ID) and spoke with a great diesel mechanic. He adjusted the valves (which were out of specs according to him) and now with no driving changes it's up to a livable 17. Still short of what others are reporting but at least an improvement.

Anthony Wallace, ID

 

[geusterman]

abranz--very interesting. Thanks for posting your experience. geusterman

 

[Pit Bull]

Mine was built in Lago's Mexico in July of 2002, 3. 55 rearend and it weighs 7000lbs with me driving. It now has 13000 miles on it and I now get around 18 mpg combined driving. I usually shift at 2000 rpms and cruise at 1700-1900 rpms. Hope this helps

 

[geusterman]

Pit Bull, are you stock? George Eusterman