why do you get better fuel mileage than me??

[rraulston]

i just dont get it. I keep reading of people who are getting 19/20 mpg with the same rig i have. I get 15. I have done everything within reason. Synthetic fluids, new air cleaner, Aluminum rims, new air temp sensor, valve adjustment, fanclutch checked. I wonder if there is a way to time the injection pump or somthing else. The auto transmission is stock, will the hopped up transmission give 3 or 4 more mpg???? I wouldnt think so, but maybe. What about an EZ box. Should i do the map sensor. I just want what they got. .

This truck is frustrating the heck out of me... ..... :{ RRR

 

[NVR FNSH]

How fast do you drive? I'm averaging ~16mpg over 42,000 miles of combined city/hwy driving. I usually run 70mph on the hwy and get 15mpg, if I slow down to 65mph I avg 17 mpg.



Brian

 

[LSMITH]

Some trucks do better than others, and always will. I get 22 MPG at 65 and 20 at 75. I know a guy that went through everything on the planet and could not get a 98. 5 just like mine to get over 14 on the highway!!!



You could try putting in a new IAT, and coolant temp sensor. The MAP is probably OK. The VA has added 1-2 MPG for everyone that I know that has it. They are getting really reasonable too used these days. The EZ has added some MPG for a few and not for others. I definately did not see it with an EZ. Other than that I really don't think there is a lot you can do.

 

[Snow man]

RRR,dont feel bad,mine gets 14-15 now at best,sometimes i get only 13 with no trailer,I used to get 16. 5-17 then i got it reflashed,and it lost over 2 mpg.

 

[KatDiesel]

Before I got my new camshaft, I would average 14. 8 mpg... . thats highway/city..... on the highway I do 72 to 75mph. I also lockout overdrive until I am doing over 55mph. I have 4. 10 ratio. Since I got a new camshadt (Diesel Dynamics) I ahave gotten 3 16+mpg tanks and one 15. 5 (lots of hotrodding after going back to DD III's).

 

[captaindean]

mpg

I AM GETTING AVG OF 18. 8 THAT I AM HAPPY TO BE GETTING WITH SUCH A LARGE TRUCK THAT I AM PAYING $2. 00 A GALLON FOR FUEL I WISH I WAS PAYING WHAT YOU GUYS WERE ON THE MAINLAND

ALOHA

DEAN

 

[Shovelhead]

Around town seeing ~15-16mpg.

On the road crise set at 65mph ~19-20mpg.

As speed increases, mpg drops. 75mph=~17mpg... . etc

This is with 6 wheels on the ground and a 4:10 gear.

 

[rraulston]

logic seems to say that if we have the same configuration of truck and i get 15 mpg and you get 20, then we do not have the same truck. somewhere there must be a subtle difference. If we could find out what that difference is, life would be great... ... RRR



by the way, whats a VA boxxx???

 

[JR2]

VA-Van Aken, it is a timing adjustment box similar to the Edge EZ.



As far as mileage goes it has lots to do with driving styly (speed, RPM, WOT runs, tire press... ) and fuel quality. There are also many different reflashes that have been done to trucks for various reasons.



I have a 2001 2500 4X4 and get about 19 on the highway and about 14 in town. To get 19 on the highway I have to drive it like I stole it to keep the RPMs up around 1900-2000 (75 mph with 3. 55 rear end). My Dad who has a 98. 5 3500 4X4 get about 17 average on the highway and about 14 in town.



To make you feel a little better:

I have kept track of every single drop of fuel that has ever gone in the truck and last year when I figured out my overall milage I got 15 mpg. Consider that my last truck was a F150 with a 351 that got 8 mpg all the time I think 15 is great.

 

[PRout]

Some people are going by the mileage computer which is just an estimate, and not accurate.



Also, with the wide range of tires & sizes on our trucks, theres no way to be accurate unless they have had an odometer calibration.



My last set of 285/75r16 BFG A/T's at 40k of wear still made the odo read 7% low when it was checked at AAA.



Pressure changes make more variation in the readings, and who knows how accurate the pump was at the filling station.



Keeping a log of mileage is the way to go, to get a real average, and check the calibration of the odo.



Yea, there were posts in the past of people having re-flashes done to the ecm, and either losing or gaining mileage. Flash version may be a major factor.



Maybe the transmission is slipping?



Mine lately has been getting 17-17. 5 w/ mixed driving, and 12 towing. Thats calculated out.



Seems to have lost about 1 mpg going to mud tires.



Maybe some people are driving downhill both ways? It must be possible, since my grandpa told me he used to walk uphill to school - both ways

 

[rubberneck]

I too have kept a log of every tank since new. Over last 25000 miles, i usually end up at 15. 5-16. 5 combo city, highway, but even highway only miles at 75 mph, never more than 17 mpg. Why do some say 20-22, i dont know, creative math?? Or maybe i just have too heavy of a foot

 

[Shovelhead]

One of our members posted about a year ago of his experiment while crossing the desert as I remember he wedged a stick on the "gas" pedal instead of using the cruise control and achieved something like 25-26 caculated not displayed mpg.

 

[tgbol]

Around town with very limited freeway I average 15. 2. If I run on the freeway at my usual 70 I get 17. 9--I have tried setting the cruise control at 55 and crossing the L. A. basin I got 21. 6, maybe it was because I was being pushed along.

 

[jkern]

mine is way low too... 14. 5 in town and daily driving, 16. 5 on the highway. i never got anymore than that even with stock tires.



my brother has a 2001. 5 HO NV5600 and gets 17 around town and 20-21 on the highway.



i too am disappointed in my milage, but i don't really think that there is much to do to fix it.

 

[Michael Hughes]

As you can see in my sig. I have a 99 with a 5 speed. Since I lost my job 6 monthes ago, my ave has drop. I was getting 20-22 MPG, now that I don't do alot of highway driving, I have been getting 17-20. When I was working I drove 100 miles a day , mostly all highway. I would say half at 70, the rest at 60. So I think it has alot to do with where you drive, how you drive and at what speed. Overall ave 20. 4 MPG in 96 tanks.



I can tell you that it is alot better then I did with my gas 360 97 2500HD. Overall ave 15. 3 MPG in 231 tanks.



What we need to do is find two guys that live close to each other, one that gets 20+ and one that doesn't get over 15 to trade trucks for a couple of tanks of diesel. I would bet the guy getting 20+ would get that out of the other truck and the guy getting 15 would still get 15.

 

[WadePatton]

21/18

Calculated with 265's, Al wheels, bone-stock otherwise.



I got 21 mpg at 80 mph on a 700 mile trip with full factory exhaust and SR in. I now get 18 around town/rural highway driving without muffler or SR.



And I'm don't baby that pedal either.



Hope you get yours figured out. And I hope to be amazed again when I mod it and the mileage gets better

 

[Big_Daddy_T]

Some vehicles are more efficient. When you look at the mileage sticker when you but the car they tell you its an average. They even list the highs and the lows which are way off average. Its the luck of the draw. when I got my truck it got 17 city. now im luck to see 17 highway. explain that same truck loss of mileage. I had many tanks where I got a flat rate of 12mpg. Ive done most of the normal fixes to bring it up but unfortunatly i drive like crap(cant fix that). I took the va off and bought a comp and even though it feels like 80 more hp my mileage is 3 mpg better. I now average 15-16 stop and go. on the open road i do 80-90 and pass everyone not doing the same. so my mileage is poor there too. I seen a high of 26mpg towing 1000#. Heres the trick 1900 rpm at 50 mph and your mileage will be great. Roads were so icey I was afraid to go over 50. If you truly want great mileage trade in this overvalved engine for a 12ver.

 

[rraulston]

the idea about recalibrating the odometer/speedomoeter is interesting. My truck came stock with 245's and i now have 265's. I wonder if that could be a bit of it. Can anyone do the math??. Maybe ime driving farther that the odo says and in effect, my mileage is really better than thought?? RRR

 

[andrewkoperdak]

fuel MPG

When I was bone stock I got a calculated average of 19. 35 MPG combined driving over 37 tanks and 20,000 miles. I just added STAGE 3 injectors (100+HP) and the last few tanks read 22+ on the trip computer. It normally read somewhere around 18. 5 MPG. My trip computer has nortoriously read about 1. 5 MPG low compared to calculated. I notice that you are a Quad and 4X4. You weigh alot more than I do. I have a standard cab 2 wheel drive, 8 foot bed. My truck weighs a scant 6000 pound. I just weighed it at work. 3500 and change on the front axle and 2500 pounds on the rear empty. Most of my driving has been with 400 pounds of rocks in the back to smooth the ride a bit. When I tow my 5th wheel I get 14. 5 MPG at 60 MPH. The lowest MPG I have seen with my truck is 9. 6 MPG going up hill pulling my 5th and with a 40 MPG head wind.

 

[WadePatton]

265's vs. 245's

YES, that's a part of it! Larger tires are putting you further down the road than speedo thinks. In older vehicles you changed the gear on the end of the speedo cable to compensate for tire/FD changes. I haven't checked into the DC way.



According to the calculator at 4lo.com 245's are 30. 5 inches tall and 265's are 31. 6 inches tall. The 265's change the effective FD ratio to 3. 42:1.



Also, what we're looking for, it looks like you are getting 3. 6 extra miles for every 100 registered on the odo. Okay that's not a whole lot, but it is necessary to compare miles to miles!