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MPG differences...between trucks

4K views 33 replies 28 participants last post by  GMCfourX4 
#1 ·
Id really like to know how some people are able to get 20-23 miles per gallon, while me, never gotten over 19 mpg. I know theirs a million variables, weight, driving style, tranny, etc etc. But no matter what I try I cant do any better. Is my truck just a POS......are people just lucky, or does my diesel fuel suck...what gives. My brothers getting bout 20 mpg on all highway driving.(2003, 4x4, dually)....WTF I cant even crest 19 with driving like an ol' blue hair depends wearing hag. My injectors are flowing fine, Inj pumps putting out desired pressures, truck runs like a top, running synthetic oil.....


Just wondering.....Am I jealous, are people fibbing me, or am I a heavy right foot driver? Seems like too much of a gap to me.
 
#2 ·
TheChevyHDMan,

Don't fret...... if you're getting 19 mpg with a 4x4
that is excellent. Not many D-max owners are getting
that kind of mileage. Lots of boasting, but not
the real world over the long haul. Maybe if you
do downhill from the Continental Divide


Edited by: 56Nomad
 
#3 ·
Don't complain man... I get about 16 max. usually less and i don't tow squat most of the time
 
#4 ·
I agree that driving habits make a difference. I guess I am lucky with my 03 GMC.


My worst mileage was 14.5 towing the 25 foot 5er. I was pushiing it. I did one tank at 64 on cruise towing and I got 16.5 . The best NOT towing was 20.5 with the cruise at 65. The roads on the 16.5 were flat with no hills to speak of on route 28 in the UP of Michigan
 
#5 ·
Erie Tom, I am real close to you! I'm in Chardon. Just got my Dmax last week. I tow a 31' Airstream travel trailer. I got 12.8 mpg on my first 1/4 tank.
 
#6 ·
He who has the biggest lie wins! I'd like to report that my truck gets 99 MPG! Now who can top that!


You get what you get in terms of mileage and when the tank is empty, you can either refill it or resort to Nike transportation. Maybe I too am jealous, and I know people have offered to send me their mileage figures, and I know there are many variables (2wd, 4wd, speed, wind, terrain, etc) to consider in why mileage figures are higher in some cases and lower in others, but I think most high mileage claims are a bunch of BS. You are looking at 6000 pound plus trucks here, sometimes towing heavy loads. Chevrolet Cavalier fuel economy isn't what one would expect.


BTW 56NOMAD, where is the picture of your truck taken in the Avatar? Just curious.Edited by: LARSONEM
 
#7 ·
I have an 03 dually with K&N FIPK and Juice, 4 inch. I get about 14-16 around town, 12-13 towing a 10K 5th wheel and have gotten 21 on the highway ONCE. Most of the time in mixed driving I get about 15-16. Tons better than the 8-10 MPG that I used to get with my Doge V-10.





Jess
 
#8 ·
I'm in the low range too compared to others.I get around 16 normal,& 8-9 towing my 12000lb 5er with a lot of frontal area.Best I got was 18.5 with cruise set on 65 going down interstate.Still better than my old F350 with 7.3 IDI turbo gets,& a LOT more fun.
 
#9 ·
My best solo mileage to date is 18.5 mpg. My best towing mileage to date is 11 mpg. My average commuting is 17.5 mpg.
 
#10 ·
Life time is around 16 and mostly in town. Best was 22 on one trip, but the next best was a little under 19. I seem to match you as well. It beats the tar out of the wife Expedition in town and on the highway. No complaints. Oh, by the way, this is the most efficient vehicle I have ever owned.
I got 12 on the highway in my 70 Pontiac Tempest and that was downhile with a tail wind.
 
#11 ·
16 is my all time best in me 03 cc 4x4. I got down to 10 pulling 4K pounds of toys at 80 mph. As soon as my tach gets over 2000 rpm, by by milage. Im not getting the milage that my cummins did but like these other guys say, its better than any other truck or suv!


Mike
 
#12 ·
I think that most folks are embellishing the truth when it comes to fuel mileage in an attempt to justify the higher initial expense of the diesel motor. I have only once gotten better than 17MPG. Prior to OJ I was averaging 13 around town and 14.5 on the highway. A little OJ and I am now averaging 15 around town and 16+ on the highway.
When I fill up, I fill until the fuel is at the TOP of the filler neck. I then divide the miles between the last fill-up by the number of gallons of fuel dispensed.
 
#13 ·
Did everyone see that???


"When I fill up, I fill until the fuel is at the TOP of the filler neck. I then divide the miles between the last fill-up by the number of gallons of fuel dispensed." -Rick


That is how you figure out your milage!!!
If there is a trick that your calculator does to get 20 mpg please send me all the specks on the calculator! Just kidding guys. There is just a little part of me that gets jealous of someone that has more or gets more than me, and obviously someone that gets 20 mpg is getting more than me.



Mike
 
#14 ·
I do exactly as Mcfly does, fill it to the brim and do the math. Worst mileage towing is 10.7, commuting is 17.5 to 18.5 depending if I do any other driving around, best ever was from Flagstaff to Hesperia 21.7, that's a 6000ft elevation drop, no A/C. Mine gets consistently 19.5 to 19.8 on the hwy A/C on, cruise set at 75. That said mine's a 6 speed 2wd. My coworker has an 02 4wd dually automatic and is happy to get 16.
 
#15 ·
My best was 19.5 coming back from Vegas, calculated using miles driven and gallons dispenced into the tank. No fuzzy math...If I wanted that I would believe the DIC. It is off sometimes as much as 3mpg since I put the Juice on....


I regularly get around 17 in my highway commute to work with some city driving.....


Bob
 
#16 ·
I only have 3400 miles on mine but just got 18.5 on a roundtrip from Atlanta to Nashville. I also used the fill the tank and do the math so no fuzzy math here. That was with the Quad Stealth 70HP tune running 75 all the way with one real good long hill. I expect it to keep getting better as I get more miles. I'll be going to the Car Show Swap meet in Carlisle, PA next week so I plan to check it again then.





 
#18 ·
I fill mine upto the top of the filler neck too. I filled up today, some in town towing and mostly highway etc. I averaged just under 16. My worst tankful was just under 13 mpg. My best which obviously was almost 95% highway I got 18.9 mpg.


I always fill her up to the max, You can fit almost an extra 1.5 gallons more after pump stops automatically.


Of course I like taking it to the extremes..seeing how much I can fill up...a 26 gallon tank...truck can still be running and take 26.7 gallons at the pump



I will be surprised if I ever hit the 20mpg+ mark though
 
#19 ·
I must say that I did not say in my original post that I am a 2x4. That is a little less in the GWCR but I know I make up alittle of that with the camping equipment. I haul a tool box with a 2.5 ton floor jack and other stuff. The 16.5 MPG towing the 7800 pound trailer (dry weight) was my average at 64 MPH. I check the speed witha GPS and know this to be correct.


I have kept a log on every fillup since I got the truck. What I think I have learn was to keep my foot out of it and I will get there 2 minutes later ,,,,,,but I get there.
 
#20 ·
Count me in with those who feel mgp is directly related to the driver's foot purssure on the GO pedal ... Without question our trucks will cruise at or above interstate speeds with ease but the faster mine goes the thirstier she gets ... I too keep a log with in which everything done to my truck is noted and all but a handful of times, I fiddle with the fuel pump until fuel is about to overflow ... to date 45,234 miles ... best ever mileage was on a trip from Raleigh, NC to Knoxville, Tn and back, running empty, tires aired up, and driven at 1900 rpm/about 64 mph in an attempt to see just how good she can get, averaged 20.4 mpg ... normal running empty at or just above interstate speed will average 17-19 ... normal (for me) mix of city/ country driving will hit 14-17 ... towing varies widely, worst every 9.5 pulling 10,000 lb travel trailer into a South Dakota head wind at 64 mph, for a recent 5,000+ mile pull of this same trailer averaged 12.4 for the entire trip (this included the 9.5 mpg tank).... mileage has increased by .5 to 1.0 mpg since adding Mega filter ... have noted varriations from tank to tank which make me think my truck is extremely sensitive to the quality of fuel run through it ... haven't found an additive that appears to make a consistent positive impact on mileage, will start using FPPF with the next fill-up to see how she runs on it ... Jim Edited by: JEBar
 
#21 ·
I routinely get about 17-18 driving back and forth to work (5-6 mile trip) and I get 19-20 on the highway (West Texas 80-85 MPH). I have a '02 crewcab, ZF/6, 4x4. I have seen as high as 23. It seems everytime I go into the Colorado or New Mexico mountain areas and have to fill up there, I get great mileage (over 20) from their fuel. They must have much better fuel than we have here in Texas. It's happened several times, so it's not a coincidence, and no it's not downhill mileage. I have a lead foot and I drive it like a diesel oughta be driven: OFF or ON. ;-) When I put the Stealth on, we'll see what that does to it...


Tim
 
#22 ·
DMAX2DAMAX,


I just got the stealth and cant wait to try it on the highway. Have you tried the 90 hp setting or any others while cruising at 75? Do you seem to think that it getts better mpg in the 70 hp setting? How about in town? If you have it in the 90 hp setting just cruising at 75 does it get too hot?


Thanks,


Mike
 
#23 ·
bybycop,


I've only been running on the 70hp tune because I don't have gauges yet. I'm trying to decide which gauges to buy but I need more information first.


I only have 3400 miles on my truck so I can't really say if mileage improvement s from the tune or the break-in, but it is steadily increasing over time. I can tell about the power though and it has a lot even on the 70hp tune. I too can't wait for the higher tunes but will until I have gauges. Probably be another week or two.





 
#24 ·
2001 Dually Crew Cab 75k Duramax 13mpg towin 10k+ 16mpg empty


2003 Dually Reg Cab 10k Duramax 14mpg towin 10k+ 17mpg empty


The fuel mileage on the 2003 is still climbing!
 
#25 ·
Maybe there is some truth to that "Colorado Blend" theory. Mine's 2wd and ZF, I've got records of every tank and it has only once dipped below 20 MPG except when towing, and that one time it was 19.7 MPG, westbound across southern Wyoming on I-80 (That's into the wind for those of you unfamiliar with the area).





20.68 MPG is my overall average to date, including the miles towing the 5th wheel or car hauler. It doesn't have oversized tires or power-adders and it generally only exceeds 2000 rpm in the immediate vicinity of off-brand diesel pickups.
Traffic keeps the cruising speed down to around 70 MPH on my commute into Denver, with the bumper to bumper crawl for the 10 miles closest to the office each day.


I buy fuel at a high volume Shell (used to be Texaco) truck stop.


I'll send a copy of my excel spread sheet if somebody wants it.


I think it comes down to a fairly laid back driving style, and some benefit of reduced aero drag due to less dense air and of course the superiour GMC front clip.
Edited by: Colorado Kid
 
#26 ·
luvthesmellofdiesel said:
... It seems everytime I go into the Colorado or New Mexico mountain areas and have to fill up there, I get great mileage (over 20) from their fuel. They must have much better fuel than we have here in Texas. It's happened several times, so it's not a coincidence, and no it's not downhill mileage. ...

My best fuel economy ever while pulling my 10K 5er was in Colorado, going UPHILL west of Denver heading east.


Got 11.7, and had been getting 10.5 on the rest of the trip.


Maybe there is something about the Colorado fuel. Can I regulary drive there to get the "good" fuel, and come out ahead???



I don't think so...



cadman_ks
 
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