Absolutely terrible gas mileage. - Page 2

**Hook'em_Horns!** · 06-15-2009, 01:22 PM

These are all covered, but MP and tire pressure along with driving faster should get you 13. Much more shifting when running 60-65mph, while 68-69mph will pull most hills without shifting.

Redeagle313 · 06-16-2009, 08:55 AM

Lots of good advice and interesting comments. I have towed a 28' TT (6000 to 7000 pounds) with an '05 LLY crew cab and overall average was about 13 mpg (all of its towing was in the flatlands of Indiana). There were times, running into 30mph headwinds, that I was at 10 mpg. Other times, running at 60 mph with a tailwind I was in the high 14 mpg range. Hiway non towing was usually in the 17 to 18 mpg range. The '07 LBZ does about 5 to 10% better than that. Recent trip to Albuquerque NM and back (2900 miles), with a big variety of conditions, averaged 13.3 MPG (63 to 65 mph) on the way out and 14.1 on the way back.

If I try to run over 65 mph, mileage drops like a rock. Drag increases as the square of velocity, so I would watch the speed.

All of my mileage figures are hand calculated, always taking the time to fill the tank to the top of the filler neck. My DIC is usually off by .5 to .8 gallons, to the negative (understating fuel mileage). Never trust mileage figures that you have not witnessed! Did you witness the tank filled to the top, did you witness the refill and hand calc it yourself? Why people have to fib about their MPG? Not sure....but they do.

08DMAX · 06-16-2009, 09:46 AM

Using the truck in the sig, 2 weeks ago, I did a 1400 mile round trip pulling a 33' RV that was loaded. Had a 10 mph headwind for about 600 miles.

Averaged 15.4 MPG, hand calc.
Never drove over 2200RPM tried to stay just above 65MPH.

I regularly get 16.5MPG pulling a enclosed tandem axle car hauler with a 2200 poung vehicle inside. 1 tank from Colorado Springs, CO. to Chicago.

I feel the secret is to do long slowly building starts and to avoid the quick use of the brakes. Staying out of the traffic clusters/packs also helps.

**1953drtelco** · 06-16-2009, 03:40 PM

It does seem that your fuel economy is a bit low. I have an 05 ext cab/long bed, stock except for an LBZ mouthpiece. Before the LBZ mouthpiece I averaged 13 mpg towing my boat....approx 6500 lbs. After the upgrade to the LBZ mouthpiece I averaged just over 15 traveling at 65 mph towing the same boat. Just cruising on the frwy I averaged 23 mpg. Much better than my 04 Dodge (Hemi) getting 9 mpg. Were you going against the wind???

Kst8er · 06-16-2009, 03:53 PM

put diesel in it instead of gas

DaleDMax · 06-17-2009, 10:24 PM

I have nitrogen in my tires of the truck pumped up to 70psi rear,for towing,60psi front. Just did a 120mile trip(10k+trailer weight) with wind and against, averaged 14mpg doing 68mph. I believe the tire inflation helped me gain as much as 3mpg. Before that the tires were at 55psi all around.

wannabefastcrf · 06-25-2009, 09:10 PM

i just bought a truck tonight i hope it does better than 13mpg or i wont be happy

dmaxguy2008 · 06-25-2009, 09:59 PM

just takes time to get it the way that you want it i bought my truck made it 100 miles and limped it had a MAF code or some crap and on top of it all i was getting 14mpg so i am a long was from that now. I get around 18mpg pretty consistently and some times 20mpg hand calc. mind you so yeah

techinny · 06-26-2009, 09:27 AM

Quote:

Originally Posted by dmaxguy2008

just takes time to get it the way that you want it i bought my truck made it 100 miles and limped it had a MAF code or some crap and on top of it all i was getting 14mpg so i am a long was from that now. I get around 18mpg pretty consistently and some times 20mpg hand calc. mind you so yeah

Me too, still on 245's, I hate the look of it, but I may never change it to keep the mileage.

PULRIG · 06-27-2009, 05:48 AM

When my truck was stock, the milage sucked! With all the stuff I have done to mine I am very impressed with the power and fuel econmy that I now have. (Look at truck stats.)
And yes, the math is correct. (calculated with the GPS and fuel consumption/fill-up)
I don't beat on my truck, I rarley go over 65 - 70. I built the truck for pulling my trailer. I didn't go very far on the stock trans. with the bigger tires and extra power. (Smoked the clutches, and the stock torq. convtr. sucks!)
With the gears changed from 3:73 to 4:56 and trans./torq. convtr. upgrade, I have no problem pulling. I'm at 2200rpm at 65mph.(due to the low gearing)

If you are smart about building the truck, build it for what you intend to use it for, and keep your foot out of it, you should be able to get everything you want out of your truck. (Milage and Performance)