Steps for better fuel milage

[rraulston]

Can somebody tell me what to look for or do to get better milage??? I get 15 mpg empty at 50 mph average. My 96 used to get 20. I thought the 24 valve engine would be more efecient??!!

RRR

 

[HC]

You say "average" of 50. If you mean your top speed is generally less than 60, then yes, you should get better, assuming of course we're talking highway mileage, not mixed hwy/city. Several folks reported regaining MPG by replacing the IAT sensor (Intake Air Temperature). Only costs you about $22 to slap in a new one.

 

[Steve Campbell]

Clean fuel filter

Clean Air filter

Clean or replace IAT

Narrow Hwy tires Vs. wide mud tires

New "slick" oil in gear train (How was that for keeping away form an oil :-{} )

Has you Viscous fan malfunctioned and is now running all of the time?

Adjust valves

How are the front tires wearing (does it need alignment)

Have you added on a lot of aerodynamic drag (brush guards etc. )?

I have heard that automatic that are out of "adjustment" can eat up a lot of horsepower.

Maybe run a tripple strength batch of fuel conditioner thrpugh to "clean out" the injectors. (It doesn't quite work that way, but it won't hurt IMO. )

 

[chuck3]

What rear gears are you running, if the 3. 54 your going to slow need to get to the sweet spot(18 to 20k rpms) if your running the 4. 10s you may not do much better than 15mph.

 

[HTRDHLR]

Explain "automatic out of adjustment"??

 

[rraulston]

ime running down the list you all gave me. Now what do i do to adjust the auto transmission???? RRR

 

[LSMITH]

If you have a 3500 you may be nearly as high as you re going to get.



When you are getting up to speed do it smartly, don't lumber up to speed. When at speed just maintain your speed up the hills, don't accelerate. When you are going to stop coast as far as possible. Don't downshift to slow, let it coast and use the brakes when needed. Don't use the cruise control, you will find that you can maintain the same speed up a hill with up to 4 PSI less boost than the CC. If you need to accelerate do it going downhill or do it quickly, don't lumber up to speed. Do not idle, start it and drive off when oil pressure stabilizes cold or hot. Put synthetics in the diffs, 75W-90 in both if you don't tow heavy all the time, synthetic ATF or 5W-30 motor oil in the transfer case. New clean fluid and filter in the trans, and properly adjusted bands. Use the lockup whenever possible, let off and let it lock as soon as possible, then accelerate fairly quick. If you have a bug shield take it off, same for grillguards. The most important of all, DRIVE SLOWER, at the speed limit or you don't have a chance. My truck is 5 MPG better at 60 than 80.



Driving like I describe has gotten me a one tank high of 24. 8 MPG with a big grillguard and 285 tires, I can average over 22 MPG for several thousand miles in the summer too. Winter mileage is about 19 average.



Hope this helps.

 

[LoneRam]

My 2c

I just wanted to add a few things. I too was after the holy golden tank that never runs dry. I read that once at speed on hwy, stay below 2k rpm. Also I have read reports of improvement with adding an EZ and DD's of some level. I haven't finished a tank since my add-ons, every 20 miles you have to turn around:{

Anyways, good thread for everyone.



LoneRam

 

[Steve Campbell]

trans out of adjustment

"New clean fluid and filter in the trans, and properly adjusted bands. Use the lockup whenever possible, " (By LSMITH)



I am not auto transmission guy. Others on here can provide even more info (than that quoted) because of their expertise.

 

[andrewkoperdak]

You know I thought that my "average speed" was quiet a bit higher until I read my hour meter (overhead information center,option on my 2001) and I found that my true average speed was more like 27. 56 mph (510 miles divided by 18. 5 hours). Remember that all that time sitting at lights and such counts against your mileage. I am in Southern Cal and all the highway speeds are 65. So it would make sense that my average would be less than that accounting for slower traffic and such. My best mileage has been 24 in Northern (Flatter) California and 17. 9 is my worst. With my cruise locked at 70 I get 21-22 as long as I am not climbing a grade. I have a stock 5. 9 with 3. 55 gears and a 5 spd. I generally have 400 pounds of rock in the back of my truck (smooths the ride out a bit). All the other reasons listed in this thread are very valid too but I found my answer when I calculated miles traveled vs time. Suggestions for improvement, well you driving style may be what needs to be adjusted and best of all it is free.

Originally posted by rraulston

Can somebody tell me what to look for or do to get better milage??? I get 15 mpg empty at 50 mph average. My 96 used to get 20. I thought the 24 valve engine would be more efecient??!!

RRR

 

[Roger rodbolt]

Originally posted by rraulston

Can somebody tell me what to look for or do to get better milage??? I get 15 mpg empty at 50 mph average. My 96 used to get 20. I thought the 24 valve engine would be more efecient??!!

RRR

Don't forget to pressure test the boost side of your turbo system, loose clamps and leaky intercoolers abound. Have you driven another similar truck? If your truck seems sluggish in comparison, your timing may be retarded. Intake air sensor that is dirty or defective will lose a few MPG. Let us know what you find.