Bad mileage !

[TexasCornBread]

Okay . Some of y'all may read my post about me back in a 3rd gen . Well I have a 32 gal gas tank takes me 120+ to fill it up . I'm only getting 12-13 mpg without my foot in it . And only squeezing 375 miles out of a tank of fuel mixed city and highway .

My 99 I'm getting 320 out of 26 gals of fuel ..

What do I need to check what do I need to do !

 

[inktoxicated]

I think these trucks just suck on fuel efficiency. im lucky to get 12. before my lift and 35s maybe 14

 

[reapercrewprez]

i am only getting hig 13 low to mid 14, but i have been doing a little reading about swapping over to a cold air intake, (but would have to be a good one like k/n) and matching up with a bullydog perfromace module. Supposedly this can add up to 2 to 4 mpg.
Now I do know this, my mileage was about 11- 13 before i have the throttle body cleaned and the injectors flushed.

I have also been doing a lot of reading about gas in general, and this goes cross platform from gas to diesel. Some oil guy who has worked in pertol for the last thirty years said that these steps would help in maintaining better fuel econ.

1. is to get fuel early in the mornings, that the colder the fuel the better liquid fill you get, this has to do with molecule expansion to the conversion of a liquid to a gas. the colder the fuel the less vapor and more liquid.

2. if the handle to the pump has the lock notches, set it on the lowest one, for the slowest fuel fill. apprently if you run it wide open the nozzle is returning part of what your paying for back into the pump due to a vapor return built into the pump. the slower the flow the more actual fuel you get.

3. never get gas while a fuel truck is on site. while the dumps are being delivered it is stiring up sedimate from the bottom and potentially sending trash into your vehicle.

4. finally try to keep your truck above half a tank at all times. You know the old saying it seems like the first half lasts a while but the second half seems to burn faster. turns out its true, the more room in the tank to more opportunity the fuel has to evap and turn into a gas and not a liquid.

i've been doing this for about a month, and though my on board fuel econ still says 13.6 -14.1 when i do the math on my milage vs gallons I am showing more like 15 to 15.5

 

[TexasCornBread]

Ill have to try that ! I do have a cold air ..

 

[LS5DodgeRam]

check your tires... i have larger tires than the stock ones, i have 32.5 as opposed to the 28ish diameter of stock tires... with the increase in circumference, it actually measures less miles per tank or gallon, since your tires are spinning less. if you have a programmer, you can adjust the tires diameter and it should even out. i had about 14.5-15.5 on the stock tires, now that i run the 32.5s... i get 11 mpg.

as for the miles on your odometer... if your tires spin less on a stock tire diameter programming, you actually go the same distance, but on the ecu you travel less miles. so until you program the ecu to run on your tire diameter it will always read less mpgs and less miles traveled, but in reality you go the same distance

 

[SmokedRam]

Your new truck has 35" tires, right? And they're M/T's? What rear gear does your truck have?

 

[wermbang]

Does Texas run the "winter" fuel mixture, mileage always sucks this time of year for us northerners.

 

[SmokedRam]

Does Texas run the "winter" fuel mixture, mileage always sucks this time of year for us northerners.

Every state has their own blend of "winter fuel"...some just have more or less butane blended in among other additive and stuff.

 

[garner]

check your tires... i have larger tires than the stock ones, i have 32.5 as opposed to the 28ish diameter of stock tires... with the increase in circumference, it actually measures less miles per tank or gallon, since your tires are spinning less. if you have a programmer, you can adjust the tires diameter and it should even out. i had about 14.5-15.5 on the stock tires, now that i run the 32.5s... i get 11 mpg.

as for the miles on your odometer... if your tires spin less on a stock tire diameter programming, you actually go the same distance, but on the ecu you travel less miles. so until you program the ecu to run on your tire diameter it will always read less mpgs and less miles traveled, but in reality you go the same distance

Your stock tire height is way off BTW. 17s with 265/70/17 are around 31.5 and the 20s with 275/60/20 are about 33". 28" is a mustang or camaro tire lol

 

[TexasCornBread]

Yes truck has 35x12.50xr20 nitto trail grapplers m/t's truck has 3:92's out back .

No programmer but it will have a programmer when I get back to work steady . What type of programmer will be best since ill be hauling my trailer a lot ! I'm looking to maximize fuel mileage

Truck has 55k on it right now ...

 

[Flashback]

You may not be able to adjust the tire size without screwing up your cruise control.

 

[LS5DodgeRam]

Your stock tire height is way off BTW. 17s with 265/70/17 are around 31.5 and the 20s with 275/60/20 are about 33". 28" is a mustang or camaro tire lol

Hmmm.. then the guy before me had a lot smaller tires on it D: all I know is that my tires are larger than the stock tires or else my Speedo wouldn't be off, I just gotta check my tires size now then lol I guess I forgot all the sizes ... Oh well lol

 

[LS5DodgeRam]

Your stock tire height is way off BTW. 17s with 265/70/17 are around 31.5 and the 20s with 275/60/20 are about 33". 28" is a mustang or camaro tire lol

Just checked them again lol yeah the guy before me had some wimpy tires then because that size came out to be 28 mine now are 34.45 inches diameter and 12 inches wide and that inch and a half throws off my computer

 

[smykowski]

fwiw my 05 seems to get about 13.5 since winter came on. dropped about 1mpg from the fall. and that's driving like a old lady (no offense to you old ladies out there) which is VERY difficult for me to do.

 

[OilCityOperator]

10.5 here , my truck is full time awd tho.

 

[WhiteExpress]

Yupper. Gen III Hemis (especially with larger wheels n tires) are just not known for mileage.
If you wanted mileage, shoulda bought a Cummins. Hello 19 MPG!

 

[TheSatinPumpkin]

lucky duck.

10.5 here , my truck is full time awd tho.

 

[TexasCornBread]

I've been hitting steady between 13-15 ! The last two days .. Mind you I'm driving like papaw does but hey . Means my truck will last longer along with good maintenance

 

[smiley]

As summer blend comes back mine will go up. These are big vehicles they just can't be that efficient at this size with gasoline and inefficient powertrain. Enter 8 speed tranny to help put more to the ground.


$miley

 

[TexasCornBread]

I'm down for a 8 speed who's got a wrecked 4th ill trade u a nice 5 speed