Mileage with stock geared 80 on 36's .. uggh

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Mar 27, 2003
Just looking over my initial VISA bill upon which I bought all my return fuel from Golden Co, and it looks like I may have been running below 10MPG. Mind you I may have bought a few snacks with some of the fuel, and I used an average of $2.25USD for pricing .. 1200 miles and change took $290 USD. :eek: FWIW I stayed at the speed limits, in cruise, and always tapped the OD off on hills .. and ran the PWR button the whole trip plus I have a Truspeed recallibrator installed.

This about right for a lite 80 running the equipment in my sig line?

Man, that sucks!

Just how much would 4:88's help here??
Huh T last time I ran mine cross country on a long distance venture she did 14/15 mpg. Now granted I don't run 36's I'm running 33's but still my rig is far heavier than yours with all the gear I carry and I am running stock gears as well. That sucks, especially having to look at it all totalled on a visa bill.:eek: Thats the reason when I do something like that its always cash so I don't have to think about it again later.:doh:
I get around 10 MPG with city and highway driving Tyler. I run 35's and have 4.88's. I do have the added weight of the ARB bar and a winch up front. two Lightforce XGT 240's on the bull bar and a snorkel. I'm sure all this adds some drag. I thought I should have been closer to the 15 MPG mark. I guess a small price to pay for driving such a heavy over engineered truck. I'm thinking better exhaust flow may help and I am in need of a new exhaust system anyway. Thinking Borla, though I have read threads about fitment problems.
--> MoJ rethinking the 35's he was going to order today.
regearing will take a load of that engine but I can't say for sure you will get the fuel economy you should. 10mpg on my truck would point to a probblem that needed repairing as I get close to 16mpg regularly.

How's your e-brake? Any play in the handle more than say a 1/4"?
I wouldn't worry about it the way you calculated it. What are you going to do anyway? Unbolt all the mods?

I just switch to Toyo MTs in a 315. I was pleased with my first tank of gas because I pulled 14mpg. This second tank I bet is almost as bad as yours. Lots of stopping and starting. It takes a lot of energy to get the big meats rolling.

There is some calculation about rolling weight vs. bolt on weight. I can't remember the figure but rolling weight of tires/wheels is significantly heavier than say bolting on a bumper. So comparing it to other vehicles that are heavir isn't really applicable. Another thing you have that a lot of people don't have is very aggressive tires. I read that the open tread patterns actually suck mileage as each tread block catches air during the rotation and slows the tire down. And of course you have a height problem with those big tires. You just created a whole different drag pattern for your vehicle and increased the drag.

Gears will probably restore some of the lost power and might bring back mileage a little but I wouldn't expect any miracles.
ginericfj80 said:
There is some calculation about rolling weight vs. bolt on weight. I can't remember the figure but rolling weight of tires/wheels is significantly heavier than say bolting on a bumper. .

Somewhere on mud I read to double the increase in rolling weight and add it to the vehicle weight. I.e. 1lb of heavier tire = the same as adding 2 lbs of static weight. Could be just a mud myth, dunno.
Arya Ebrahimi said:
Damn dude, you get 10mpg w/ 36's!? Lucky bastid! I'm getting 9-12mpg(city/highway) on 285's.

Yours is youth and driving style induced however.:flipoff2:
Thats why I plan on sticking with 33 for road and picking up some 35 SS for trail only. It does not take long to pay for itself. But hey your rig looks great.
Hey Tyler............I know this is off subject but, your a Henry Rollins fan?

Oh and , my beast gets 9 in town and 12 on the freeway. Talk about crappy!!:crybaby:
4dmalamute said:
Hey Tyler............I know this is off subject but, your a Henry Rollins fan?

Shhhhh, it's much better than a belly shot. :flipoff2:
My 80 is 4:88's and 35" Truxus M/T's With the stock pulley on the S/C I get 11-13 and can get to 15 on long highway trips (if I'm not in a hurry). If I'm running the 3" pulley and the secondary rising rate fuel reg I drop to 9-10 mpg but the grin factor is much higher. Lower gears will help but rolling and wind resistance of lifted trucks with larger tires will eat at the fuel budget! Face it....these trucks are pigs!

is that corrected speed? I assume you used your GPS for teh calcs?

Anyway, air drag caused by taller vehicle and knarly tires will do that to you. Not to mention the weight of those rubbers must be a lot! Once your're moving, the engine isn't doing too much work with 4.11s and 36" I'd imagine. I'd think you should get a little better mileage than that!

My 3" lifted rig with lots more weight than you (about 6800 lbs) averages about 12-16 depending on elevation and head wind. I'm running 315s Geolanders with 4.56s.

he's from up North, he must use different miles and gallons...

anyway I got 16.7 mpg (US) on over a thousand miles of freeways and highways with 285s, fairly heavily loaded. Inflated the tires to 60 psi, though, that must have helped a lot I think.

(oh, I would not think the PWR mode helps mileage...)
(Yeah, a Rollins fan .. )

No worries .. I'll only see gross $ losses when I do out of town trips. In town I average only 600 miles a year. :flipoff2: Gotta love a short commute! That is a big part of why I built my 80 this way. The day to day expenses aren't increased hugely like a DD guy with a similar build putting in 100 miles/day.

Like I said too, I ran the speed limit because I was trying to set some sort of distance coverage in a day record apparently:rolleyes: , but could have done better if I'd gone slower, and also if the incredible Nebraska crosswinds weren't so dramatic!

Rick, I'll check my e-brake today.

I am driving to Toronto in the spring, so I'll document everything closely and recheck.


Ok, I went for a cruise, and when I got to a quiet spot I found a written fuel log I kept for 1300 miles. I logged odo, fillup $$ & $$/gal. I totalled everything and did the math. My actual mileage is 11.27 MPG.

Sm0000000kin!! :D

Rick, can you help me out on the ebrake? Thats the hand brake no? Where do I look for slack in the system exactly?

to start just pull up on the handle in the cab. If there is more than say 5mm of free play then the e-brake bell cranks are probably seized and holding the e-brake on which would tend to slow you down.

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