So here are the results from my first big road trip with my new trailer. I did about 730 miles.

Tank #1 - 6.9 MPG
Tank #2 - 7.7 MPG
Tank #3 - 8.7 MPG
Tank #4 - 6.4 MPG

So I figure my trailer with 2 4-wheelers and other stuff in it is max 8000lbs. And I realize my truck is lifted and stuff but are these numbers acceptable? I don't think they are. My Dad's old 1973 Chevy 350 V8's worst gas mileage ever was 7MPG pulling 8500lbs. That makes me want to sell mine and get and old beater. Any suggestions?

 

How fast were you going while pulling the trailer? Those 37" tires aren't going to help anything. It sounds unusually low, but I would like to have more details about your speed and the type terrain you were in. (hills, mountains, etc.)

 

Did you regear or at least have your speedo recalibrated? If not your speedo will be way off.

 

I was driving between 60 and 75 MPH. It did not seem to matter what speed I went. 1/2 of the trip was uphill/downhill and the other 1/2 was nice flat roads. 60 MPH in 5th gear would put me about 2200-2300 rpms, 75 MPH in 6th gear put me about 1900 rpms I did a tank of each and then mixed my speed on the other tanks. As you can see it didn't make much of a difference. I get 12-14 MPG empty which I have learned to accept but the towing MPG is sad.

 

What gears do you have? I'm guessing the 3.73?

 

All the figures I put on here are corrected hand calculated numbers. From mile marker to mile marker my odo counts .85 miles. I have checked this many times. So when I do a MPG check I take the number of miles my odo counts lets say 250 then I multiply it by .15 (the difference). 250 X .15 = 37.5 + 250 = 287.5 miles traveled / gallons used.

 

3.73 gears

 

Did you recalibrate your speedometer?

 

How many miles are on your rig...I thought it was brand new. It should get better with a few more pulls.

 

From what you're saying you're doing the math wrong.

Take the miles from your odo, and DIVIDE it by .85.

250mi on the odo = 294.1 "real" miles

An error of about 3% in your mileage.

 

3% isnt going to help him much :/

he needs like 15% better

hauling a 5000 pound load with my truck, i was getting 15.6 or something in that area, something is really wrong here :/ or the numbers are off even more.

 

For what it's worth I have pulled my trailer once 660 miles and averaged 9.9 MPG. I had 7000 miles on the truck at the time. Dry weight on the trailer is 9300 lbs so I figure I was towing near 10000.

 

I have read something once that stated loss of mpg due to factors...

.5 mpg per inch of lift
1 mph or more due to tires...may 2 in case of 37's
1 mpg due to push bar/lights/etc.

Add it up...5-6 mpg may be a reasonable loss for that truck. I have 35's with a 4.5 inch lift and a huge push bar and never see better than 17 max empty. I average 15...and have got as bad as 10 pulling...

 

Whooa, no wonder your getting bad mileage.

If you're going 75 with a 15 percent slow speedometer, you're actually going 86 mph.

86mph pulling a tagalong trailer, not a good idea in the slightest.


Sweet spot is right around 60mph which would actually be 52mpg on your speedo.

Mileage goes down a little between 60 and 65, anything after 70 it drops like a rock.

I can get 20mpg at 60mph (according to overhead)
15mpg at 70mph
11 mpg at 75mph
Won't even attempt to get my truck up to 85mph, that's just crazy.
This is all empty, as I am poor and can't afford anything to tow.


I'd be getting that speedometer/odometer corrected ASAP, so you aren't risking life and limb,
not only your limbs but others on the road with you,
let alone wasting fuel.

At least get a GPS and use it for your speedo,
then put some gaffer tape over your stock speedometer so you can't look at it.
You can get it in just about any color nowdays, so it will match your dash.
(gaffer tape being another name for duct tape)


phox

 

The speeds I stated were corrected speeds. I have learned the error and drive with the speedo lower then actually speed. For example when I stated I went between 60 and 75 my speedo was between 52/53mph and 65mph.

Maybe I got a left over early build motor? Maybe I need a chip? Maybe I need a gasser? Maybe I need to leave the truck stock?