[NorCalDuner]

I just got back from my first trip towing about a 6500# toy hauler from Sacramento, Cal. to So. Cal. and back,about 1200 miles total. I only could manage to get 10mpg at the best, and the worst was 8mpg. I usually get 13.5mpg unloaded with 80% hwy and 20% city driving, and I am not to happy with that either. I wanted to make this first trip before I made a decision to take the truck to the dealer. I have 12,000 miles on the truck and the fuel filter was changed @ 8,000. On my trip I had the cruise set @ 65mph , I know that you will get low mpg's with that speed, but not 8mpg!!! Has anybody else had this problem? Other than the mpg's, the truck towed great, and no overheating (knock on wood).

 

[mad]

Hmm, I don't do any long distance towing so can't comment there, but...
around town, before I did any mods, I got 16 mpg bone stock with my 245s. Just adding fuel additive on every tank immediately got me another 1 mpg. Adding my intake and exhaust I now average 18 mpg around town. I don't have a heavy foot either, though. I forgot to look at your signature prior to this reply so don't know what tires you're running. Good luck, and if you aren't using a fuel additive, you need to IMO.

 

[banshee42096]

i would think thats low when i tow my trailer 10000lbs approx.
65mph tow haul mode i get 12-13 mpg no problem.at 60-65 mph
unloaded i get 20-21 or 21-22 cant remember been along time
driving that slow):h .city highway mix i get 17-18mpg.good luck

 

[dwrat]

I tow a toy hauler about 10,000 pounds and if I keep it at 65 mpg I can squeak out 10 mpg. 70-75 mpg and its about 9 mpg. So I say your towing mileage is fair but your unloaded mpg does seem poor to me.
Dan

 

[mountainstoner]

My truck has just over 10k miles, and unloaded I get just over 15mpg in town and right at 20mpg on the highway. I am not a lead foot, but I do like to hear that turbo every now and then. I don't use any additives.

I should add that around-town speeds average 40 mph, and that mileage on the highway is at 65-70mph. I set the cruise at 80mph on a 100-mile stretch of flat west Utah interstate a few weeks back and averaged just over 15mpg, so speed (and rpm) really make a difference...

 

[dmaxdzel]

Last highway trip I took I set the cruise at 65 and the best mileage I got was 19 mpg. That's the best I've seen from my truck. On the return trip I pulled a 3,000 pound trailer and got 14 mpg.

Previously, I pulled a car hauler from Ft. Myers FL to Cedar Rapids, IA. The truck had less than 10,000 miles on it at the time. The trailer weighed on a Cat Scale at 13,500 pounds. With the cruise set at 65 I never saw less than 11 mpg.

 

[bamabadboy]

10mpg at 65mph towing 10K lbs. 19mpg empty.

 

[larry moore]

Mpg

LLY with just 4k miles.
I just got back from a 3000 mile trip to Arizona. Pulled a light trailer [ie 5k#'s] abt 2000 of those miles [60-65MPH]. The balance was hwy[65mph] and off road[15mph]. Averaged 15.7 MPG for the total trip. Never under 14MPG with the trailer.
Think this is abt what others are getting.

 

[dedunlap]

I came back from a trip pulling 14k and I averaged just under 11mpg. My average speeed was 65-70 and we had a couple 10% grade hills. I took that same trip last with my 98 dually with a 7.4L and my average was 3.9 pulling the same trailer. Your mileage isn't great but the other option is alot worse. My father was pulling same weight with a ford(7.3L) and he averaged the same on mileage as I did.

 

[lakingslayer]

I just got back from my first trip towing about a 6500# toy hauler from Sacramento, Cal. to So. Cal. and back,about 1200 miles total. I only could manage to get 10mpg at the best, and the worst was 8mpg. I usually get 13.5mpg unloaded with 80% hwy and 20% city driving, and I am not to happy with that either. I wanted to make this first trip before I made a decision to take the truck to the dealer. I have 12,000 miles on the truck and the fuel filter was changed @ 8,000. On my trip I had the cruise set @ 65mph , I know that you will get low mpg's with that speed, but not 8mpg!!! Has anybody else had this problem? Other than the mpg's, the truck towed great, and no overheating (knock on wood).

Is that hand calculated?

 

[otis]

Duner that does sound low especially the unloaded mpg. You might want to ask your dealer to do the reflash, some have had a little better mpg's afterwards. Good luck.

 

[msrasmussen]

Everyone posts about the weight of the trailer when they are talking about towing MPG's..While weight certinaly makes a difference another thing to consider is the shape/size of what your towing. A flat bed trailer loaded to the same weight as a simular length toy hauler will most certinaly have less wind resistance. I feel that the wind resistance makes a much bigger difference on MPG's then the weight. If you have a boxy trailer you have all that force of the wind pushing against you in addition to the weight, working your engine harder and lowering your MPGs. Take that into consideration when comparing MPG's with overall trailer weight. To be accurate we need to be comparing apples to apples.
Example: I towed a 25' car trailer, loaded to about 5000 lbs but non of that load was more then the height of my tailgate. On an open county road at 55mph I was still getting 15-16 MPG (which is typically what I get around town driving freeways, empty). I'll be taking a trip with a travel trailer soon (sticks up above the height of my roof), roughly the same weight, will be interesting to see the results.

 

[tess tickle]

1400 mile round trip from southwest Nebraska to Oklahoma City , 75 to 90 mph, 25 mph headwind oneway. Filled up three differant times ,everytime I got a little over 15 mpg.Turned over 9k miles somewhere on the way back. I guess I can't complain.

 

[NorCalDuner]

I am running 285 tires, but my mpg's never changed when I switched from 245's. And yes I am hand calculating the mileage. I was wondering about the reflash, has anybody done this with success? THANKS FOR ALL THE REPLYS!!!

 

[CBRJohn2000]

I am running 285 tires, but my mpg's never changed when I switched from 245's. And yes I am hand calculating the mileage. I was wondering about the reflash, has anybody done this with success? THANKS FOR ALL THE REPLYS!!!

When you calculate your millage, how do you compensate for odometer error? If you are not you are not getting an accurate milage result.

The stock tires turn 662.0 Reveloutions Per Mile (RPM) and your 285's turn 614.0 RPM. When your spedo is reading 60 MPH you are actually going 64.7 MPH. So your spedometer and Odometer are reading 7.8% slower than actual.

For refference, I got thoswe figures from the following link. http://www.miata.net/garage/tirecalc.html

John

 

[NorCalDuner]

Even with that difference it shouldn't be that bad. I would think I would get better than 8 mpgs. If I had my speedo recalculated I would still be only getting like 9.5 mpgs. right? Thats still horribly bad.

 

[biggar]

Even with that difference it shouldn't be that bad. I would think I would get better than 8 mpgs. If I had my speedo recalculated I would still be only getting like 9.5 mpgs. right? Thats still horribly bad.

I pull my 10,000 lb toy hauler at 70ish and get about 8 on the DIC. I'm also running 285's. Add the 7.8% and it's close to 9mpg. Still disappointing to me, but I've hauled a lot with gassers and gotten 5-6mpg (even less on occasion) so 8 or 9 is a lot better than 5 or 6. I only get around 13 or so unloaded driving with a heavy foot and my Edge on level 4. I know I could do significantly better if I drove more carefully. I've heard that 1900 RPM is the magic number for mileage. With you're 285's fitted, that means you're rolling at and actual 66mph according to the Edge. I just like to roll a little faster than that and am willing to pay the penalty I guess.



Gar

 

[banshee42096]

its just not brand specific my father-in-laws friend just bought 06 dodge
duelly 4x4 extenda cab and he only gets unloaded 9-10 mpg if lucky
gets 11 now thats bad being unloaded i would have a personal fire
in my back yard if my truck had that bad of milage.tires do matter
i put my warranty tires on and get almost 1 mpg more of the dic
so i would think with 285s its even more farther off .i have hand ca
lculated my milages with a gps so the tire thing dont bother me.

 

[otis]

I am running 285 tires, but my mpg's never changed when I switched from 245's. And yes I am hand calculating the mileage. I was wondering about the reflash, has anybody done this with success? THANKS FOR ALL THE REPLYS!!!

Do a search for reflash. There have been several threads on the subject.

 

[lakingslayer]

How fast do you drive when unloaded? I think you have a legitimate issue since I've never seen less than 14mpg unloaded but that's driving with a large HP tune and heavy on the throttle and tons of black smoke. I sure hope you can find out what the deal is.