Engine/Transmission (1998.5 - 2002) How Can Iget The Best Mpg

[SGreenwood]

I HAVE A 1998 2500 QUADCAB SHORTBED, 4X4, AUTO, W/OD, K-N FILTER, 410 GEARS, 265 TIRES, 3. 5 CLEAR THRU EXHAUST. THE TRUCK CAME WITH 245 TIRES STOCK. I'M CURRENTLY GETTING ABOUT 15 MPG USEING MY SPEEDO TO CALCULATE AT EACH FILL-UP. I WOULD LIKE TO GET SOME WHERE IN THE 19 MPG RANGE WITH OUT SPENDING A MINT. I WAS THINKING OF CHANGING MY TIRES TO 305'S SINCE MY GEAR RATIO IS 410'S, I THOUGHT THE 305 TIRES MIGHT HELP COMPENSATE FOR THE LOW GEARS. ALSO I,M COSIDERING A 4" EXHAUST. . WHAT KIND OF "MPG" IS REALALISTIC FOR THIS TRUCK? WHAT CAN I DO? KEEPING IN MIND THAT I TOW A HEAVY TRAILER APPROX. ONCE A MONTH BUT MOST OF THE TIME I'M EMPTY GOING BACK AND FORTH TO WORK USEING THE HIGHWAY. I'M GENRALLY ABOUT AVERAGE ON THE THROTTLE.

 

[chrleb1]

Sometimes adding a box will help you out with MPGs. The more timing you have the better it will be. You could try that. Sometimes adding taller tires doesn't help all that much. The problem with that is you are adding to your rotational mass which makes it harder to turn. Some people add an overdrive unit and that helps too. I think you can add a mystery switch also, this will let you lock up earlier and give you com better mileage too.

 

[Sageair]

The problem with changing to 305 as mentioned is that they are wider as well as taller. Now going to fairly narrow 19. 5 might be the ticket.

 

[2ndgen2500]

look at my sig... i currently get 20mpg, and about 18. 5 towing moderate loads. i got 21. 8 on my last highway trip. mods bumped me up from 17. 5. and i calculated this on paper, not using my overhead computer.

 

[KIseminger]

They are right on the tires. I went to 285's on my 02 and lost 1-2mpg. Along with what these guys have told you; you can try going to synthetics on in your motor, trans, t-case, and diffs. I have AMSOIL in my truck and I picked up about 2mpg. I am using there 5W-30 diesel and like it. There is also a product out there called a Turbo Air Guide or TAG. You can so a search on that as well and find some good info.

-Kyle

 

[RowJ]

SG

Your actual mileage is probably about 15. 5 mpg. Bigger tires make your speedometer incorrect. My 285's make it 8% off. Your 265's = about 5%. When you show 60 mph your actually at 63!.

I'm not convinced bigger tires cost true gas mileage, other than possiblity of increased drag from raising it a little higher.



I get frustrated when I hear about mods adding mileage. I believe you, 2ndgen and others, I just can't get it to work for me?



SG - You don't mention your Total miles - if under 50,000 it may get better in the future. Many have reported increases between 30,000 & 50,000 as the engine loosens up a bit.



Also, winter (blended) fuel make a difference. You don't say where you live but may get much better come spring.

Good luck

 

[SGreenwood]

my truck has about 160,000 miles on it now and i live in new jersey. in the summer time i may get another mile or mile and a half. but the main reason i'm looking at a tire size change is becouse my gear ratio is so low (410's) and these trucks could pull down a house with all there torque so i have enough power. so instead of doing a pricey gear change to the mid 3's range, i figured i would compinsate by increasing the tire size. also i'm really not looking to go to a skinny tire becouse i do snow plowing and do go thru mud sometimes



i read about some guys useing something that automacticly locks up there torque convertor about mid 20's mph. i think it is made by banks ? i'd rather use somting that automaticly locks and unlocks the convertor than a mystery switch that could be left on by accident and then cousing codes in the computer

 

[OTRPU]

Thing I notice, driving around 10 or 11 hours everyday. . . when I go slower I generally get better fuel mileage. Course it's boring as hell.



Cheers,

Steve J.

 

[SGreenwood]

I DON'T FEEL THAT I'M HEAVY ON THE FOOT, I USUALLY TRAVEL ABOUT 65 TO 72 MPH ON THE HIGHWAY

 

[bmoeller]

Originally posted by SGreenwood

I USUALLY TRAVEL ABOUT 65 TO 72 MPH ON THE HIGHWAY

With 4. 10s, for better mileage, they like (at least my truck w/ 12v and 4. 10s, and scales a little over 8k w/ me in it) going in the 55-65mph range. I can get 16. 5 in the summer running under 60, but can still get 15-16 running 70-75. Will see what is like this summer with the new plate. How hard you put down your right foot will have bit of an effect. If you are getting 15mpg w/4. 10s and winter fuel, I'd say you are doing good.



Winter isn't going to help you having to run blended fuel. I always lose 1-2mpg. in the winter. Partly due to more warm-up time.



I gained roughly . 5mpg w/ the 5" exhaust. I use Lucas fuel additive, and I gain anywhere from . 5-1mpg with it. Depends mostly on the quality of the fuel.



Some have claimed small gains with 275 RV injectors and Edge EZ box.

 

[Chief USA]

If you want to get 20+ mpg... ... ... ... SLOW DOWN. Just as simple as that. At 75 mph, my mileage falls off to about 14 - 15 mpg. When I poop along between 52 - 57 mph; the mileage jumps up to around 21 - 23 mpg. Speed and resistanc is what kills your mileage. As you double your speed, the drag/resistance on the truck is squared. The faster you go the crappier the mileage will get. 45 - 50 is the best mileage speed in my opinion but it is not alway practical to drive that slow in traffic.

 

[JR2]

15-16 mpg is not bad mileage, its about what I get on average. I do worse in the winter (crappy winter fuel) and better in the summer as long as I don't drive too fast. Your best mileage is at no more that 65 mph in the summer.



After 2 years of tracking my mileage for ever tank my average was 15. 1.

 

[SGoodman]

I would agree that speed is a major factor, and even though big tires look cool they also raise your truck a small amount which increases drag, and the tread makes a difference too, there are a lot of factors to deal with on that one. Do you use additives? That's helped me a little, plus I'm still breaking it in.

 

[DF5152]

also alot of these guys getting the better milage have 4x2's less drag all around

 

[walkabout]

Let the wife drive

My pickup gets two to three more miles to the gallon (19-21mpg) when my wife drives than when I drive (17-19mph)





I do notice a big change between winter and summer fuels.

 

[DHoleman]

With the 4. 10 gears tire size,Idon't think will make that big of adiff. Not the size he's talken anyway. I for got to look at the truck specs, is there a free flowing air filter in place.

TST Products has the lock-up switch {tstproducts.com}

Derek

 

[ben_ak]

I have a '00 Automatic 4x4 - bad combo for mileage - and I got 19. 8 MPG on a 500 mile trip with 90% of that highway and 10% "city" driving. I have since installed an ARB bumber that I'm sure I will take a hit for. Also, the winter really hits me hard up here, as JR2 said, crappy winter fuel and week long stints in the twenty below range. One thing I know really helps is tire pressure - be sure to keep yours within reason for your typical load.

 

[2ndgen2500]

i actually get better milege when going around 75-80... i have 4. 10s and 285 75 16s on there, i dont know what it is but this milaege is super

 

[KIseminger]

When I had the 265's on my truck I would get about 17, sometimes higher. When I put the 285's on it dropped off to 15 and sometimes less. Although I got 18 off of my last tank. I do notice the cold hurts me too. I have not been doing as much interstate driving as I used to. So I end up just driving around town maybe getting up to 45-50 for short periods. This does not get the gear oil very warm so it's a little harder to turn. I have AMSOIL, but it's not a cure all solution.



Bottom line is, sometimes I get ****** when I get crappy mileage, but then I think of how it could be if I had a gasser.

 

[jraker]

My truck was getting about the same milage until I added the Banks system to it. I have 315's on w/o a lift and 410 gears. On my way from Seattle to Huntsville I averaged 20. 3 mpg at an average speed of 72mph for the 2600 miles. I was pulling all my worldly posessions in a trailer (I have no idea about the weight, stereo equipment is about 2000 lbs all by itself though). My in city driving is now averaging 15. 3 mpg.



The drawback to adding the Banks system is I blew my LP in the first couple hours of haveing it installed. (I had it installed at 71,000 miles) I also think it has stressed my transmission as my converter is starting to slip.