Tree DR

I'm not sure how many 3gen truck people are on this forum, but lets see if there is a comon set of things or thing that helps these trucks get good MPG.
MPG you got.
What year is your truck? 03-04, 04.5-05, 06
2wd/4wd?
Single or dually tires?
Is it stock? y/n
What tires, size, brand, psi?
Physical modifications, bed caps, toppers, lifted, ect.?
Intake mods, stock, stock/different filter, intake replaced, ect.?
Exhaust mods?
Fuel mods? Brand, what setting, turbo.
Miles driven/gals used?
Speed?
Wind, air temp, and elevations?
Hand calc. or computer mpg?
Fuel additives? Brand, how much.
anything else that has relavance.

big jimmy

Although I'm not 3rd gen this might help the conversation. When I went from 235/85's to the wider and slightly shorter 265/75's I LOST 1.5 mpg.

Jimmy

newguy2005

um...... how about by a hybrid or geo ? i have an 05 and i get the best mpg when i RIDE My BIKE!

arcojet

I Have had a 2000, an 04 and now an 06.The only mods on them all are 35's with the leveling kit. I pull the same 4000lb jet boat with the same 2000lb camper on. With the 2000 I was new to diesels and was so happy with the power I didn't track mileage. With my 04 and auto trans.I consistantly got 15.5 mpg loaded and 22 empty doing between 60 and 65. With my 06 and G56 trans with 3500miles I am getting 11.5 loaded and 15 empty on the hiway going between 60 and 65. I never get in a hurry!! The strange thing is-- I get 1 to 1.5 mpg better milage in town than on the hiway, Whats up with that???

triplenickle

Speed kills! The #1 way to keep your MPG's up is to keep you speed down! Preferably below 65, the sweet spot for my 04 w/ 4.10 rearend is about 58 mph. Cruising between 55 and 60, I have seen overhead readouts sustained at over 24 MPG. My tach reads exactly 2K RPM @ 65 mph, and around 1750 between 55 and 60. When I kick it up to 65, the overhead drops to around 19 or 20. Still, considering that this beast weighs in at 7K, not too shabby. All this was done in a western NY winter, with no fuel additives of any kind- Im still not sold on them, MMO however sounds decent, due to the lubrication properties.

sweetwaterguy

My only long trip was in January. I went from Lander, WY to Yuma, AZ and spent three days driving in and around Las Vegas. We drove almost 2500 miles and had a hand calculated 20.4 mpg's for the entire trip. The overhead average was 19.9. I use Stanadyne and have no modifications on my 04.5. I drive to try to get the best mileage. No jackrabbit starts and keep my speed at or near the speed limit on the highway and do not exceed 70 on the interstate. I will typically average 20 and change when driving to Casper, WY and back--about 300 miles.
Currently my overhead is reading 17.4 with 200 miles since filling. I live two miles from the city limits and have not been anywhere except to town and back. I did drive to town for breakfast three weeks ago in -30 temperatures and got to see first hand how cold weather effects mpg's.
I hope this does not add to the mystery of fuel economy. I am convinced similar vehicles driven the same way will have differing fuel economy. That is an another issue that needs explored.

BigBlueBeast

Overhead showing avrg at 14.8 mixed 60 hwy 40 city with only 1300 miles on it, last hand calc showed 16.3 and usually overhead bounces back to 15.8-16.3 after one 106 mile round trip to work but not this time, unsure why. Best MPG appears to be at 63/64 MPH

TexasCTD

My truck seems to average around 15-15.5 combo city/highway driving with me hand calculating every fill-up. Overhead is usually slightly higher. But I typically drive about 75 on the Interstate and the rest is stop/start city traffic.

For short periods of time, I have slowed down and my mileage goes up quite a bit. I think I got about 19 one time on a long trip in the ice, when I slowed down.

My truck weighs over 8000lbs, has 285 tires, Ranch hand Front end w/winch. Also it is an automatic and has 3.73 gears.


Seems like I read somewhere (I believe it was in TDR Mag) to get the best mileage you want to keep your Turbo Boost around 6lbs or less and EGT at 600 degrees or so.

I think some trucks are just destined to get better mileage than others. But I am not to upset that I "only" get 15-15.5 in my 8000lb truck.

underwoodtransp

6lbs of boost. I won't even be able to hold speed doing that. now the 600* thing no problem I ran about 350-400* at 15-20psi and 70-80mph up to nd this weekend.

goose2

I used to think my 17-18 mpg was bad, untill I asked my nephew what he got on his jeep liberty.(16 mpg on the freeway) With my ctd weighing in at twice the weight and a whole bunch more power. I fill pretty good with my mpg.

Herrin811

im tickled pink over my mileage The biggest factor I see is that tis engine wants to get out and run...stop-and-go murders my mileage

TexasCTD

Underwood,

Well unless im on level ground or going down hill, mine will be pushing more than 6lbs of boost too, at that speed. I am just repeating what I read....that 6lbs was supposedly the most efficient for mileage. I didn't say I followed the rules though.


Your EGTs really surprize me though! I wonder what is making yours run so cool! Are you sure your EGT probe is reading accurately? There is no way my truck would run that cool at that speed unless I took my foot off the accelerator. And, I am running an AFE Stage 2 and straight thru Magnaflow Muff (no kitty).

djbikeman

Is your pyro at the exhaust tip? Just kidding. That seems like VERY low EGT's for that boost and speed. I am usually around 800-950 preturbo at 15-20psi.

It all goes hand in hand. Lower speed=lower power required=lower boost levels=lower egt's.

There is no way I could keep the boost at 6psi unless I drove flat roads at 55mph. The only flat spots on the roads I drive are the top and bottom 10 yards of the hills I constantly go up and down.

I am a road rep for a living, so 55-65mph is not an option, especially since I drive I-80 almost everyday.

Really the most important thing I do is stay on top of maintenance, make sure tires are inflated properly etc. I have added Rokktech, exhaust, and intake and that helps in more ways than just mileage. I am getting close to what my 04.5 averaged (~18mpg) with a little over 10k on my 06 (~16.5mpg) so I figure it will come up as the weather warms (after the 18" of snow that's coming melts).

bluebull

The 600 degrees refered to in the TDR is for pre turbo, I suspect underwoodtransp is located post turbo. Even at post turbo if your running 15-20 lbs of boost the temps should be higher. Usually if post turbo pyro reading you can add 300 degrees to get pre turbo temps.

TexasCTD

Ok, thanks Bluebull. That may explain the difference in temps then. I guess I just assumed that everybody was like me...LOL.....and ran the pyro temp sensor in the exhaust manifold pre-turbo. Never occurred to me about the post-turbo temps.