so ive had my truck for alittle over a month now. so how i managed to put alittle over 2000 on her. no biggie, she has 56k on her. i bought an extended warranty on her and everything. my problem is it seems every tank im getting about 11-12 mpg. im not loaded with anything, im doing around 60-65 mph. i had the dealer look at it before and they didnt find anything. i called them last week and they told me that if she isnt throwing a code or a CEL then its hard for them to look for something. i only have a intake and exhaust.

im trying to get this issue resolved before i throw some 35s and my xzt on. that way i know she is good to go before i start doing stuff to hurt the mileage. you know what i mean? also, would the fact i have 4.10s on her with only 33s be an issue? i find that alittle over 2k rpms im doing around 70 mph. i know 35s will bring the rpms down, but would that help mpg? thanks for the help.

 

There's a lot of variation in millage , the 4:10s are part of the problem , anytime you reduce your RPMs , your going to improve .
Its too late now , but if you are not going to tow heavy loads in a lot of up hill , the lower gear numbers help millage , but with the newer trucks that option has been cut in half [ not sure what yrs , 3:55 & 4:10 , then later the choice was 3:73 & 4:10 ] , with the ability to crank these trucks up , I do not think they need the gears they come with , except for extream towing .

 

The larger the tire the worse its going to get too.

 

Which tranny? My six speed '05 gets 17-18 empty at 65, which works out to about 2100 rpm with the 3.73 and the original 265/70 R17s. I get 12-13 towing 7500# at 50 mph on hilly, twisty roads, and the huge reinforced gate on my modified landscape trailer doesn't help a bit. It's like pulling a wall through the air.

I have only put 10K miles on the truck. Not even broken in yet.

Something doesn't add up for your mileage to be that low, unless you can't keep your foot out it.

 

no i keep my foot out of it. 65-70 is as high as i roll. i have the 48re..

 

I noticed with the 295/70/17 s and the BDTP on economy, my truck gets better mileage everywhere. Last tank was 15.9 in Orlando traffic, and last trip was 17.1 @ 78ish mph. That was a hair under 2,000rpm for me.
I have heard the 315 hurt in town mileage a bit, but I dont know that from experience.

 

hows your fuel filter, air filter and eng fluids?

brett

 

I just finished a ~1800 mile trip and here are my hand calculated results for the first three tanks, have yet to fill up for the fourth.

474 miles on tank
32.003 gal
14.8 MPG

490 miles on tank
26.905 gal
18.21 MPG

503 miles on tank
29.980 gal
16.78 MPG

These are all unloaded cruise set between 70-80 depending on speedlimit. The first tank was all mountains. I had the predator set on performance/economy with the puck off.

Keep in mind that the overhead is always wrong. It is currently showing an average of 21.7 MPG for the trip.

I have 3:73 and the G56 which is the same as 4:10 and the 48re

 

GOOD info travis, appreciate it.

 

I usualy get 20 + with 3.73's. Fairly stock.

 

I just did a trip 290miles one way, filled up when I got there and doing between 65-70 I got 20.5 mpg with 285/75/17 toyos, that was Louisville to Lexington to Gatlinburg, so I had to cross a few mountains. I seem to lose about 2 mpg for every 5 mph I go faster, after 70 it drops even faster. Auto and 3.73

 

I have a 6 inch lift and 35s on my truck. I also have only 3.73s and im at 2100 rpm @ 80 mph.. The lift and the tires really hurt my fuel economy but i still get like 13 on the hwy.. it has to be your gears.. and the 35s will be taller and wider but hey.. they will bring your gearing down a little though.. lol

 

I have the same size tires as Trkenvy and 4.5" lift with 3.73's and I see in the 17's on the freeway at 75-80 and get around 12 with 10k behind it. I started out getting 10-11 new and didn't see an improvement until I started towing..

 

I drive at 1800RPM (65MPH) and keep my tires at 80 PSI. I picked up about 2 MPG going from 55 PSI to 80 PSI. You do seem to loose 2 MPG per every 5 MPH increase in speed.

 

I drive a lot like annabelle. Usually 1800-1850rpm and 64ish MPH.

My stock 265/70-17s all have 80psi as well.

As I only have 2WD I have an advantage!