2wd Tire size for best MPG

[McGIDI]

I have a 85 regular cab 2wd and i want to figure out how to put a leveling kit on it and i want to put a bigger tire size on the back to try and get a little higher top speed as far as cruising... i only tow a race car that weighs about 2200 lbs and a 16ft trailer so its really nothing but i daily drive it and want to level it and put a bigger tire and better wheel on it.... any suggestions

 

[McGIDI]

it has Banks non wastegated system on it

 

[whiteboyslo]

Always a crap shoot. Larger circumference means less RPM, but more grunt to get it rolling and keep it moving. If you're concerned with MPG, try cutting down the rolling resistance. Skinnier tires (215 or 235) with a tread pattern more highway-oriented than off-road.

Mike

 

[Coyote_Red]

^^What he said^^^ I went from an EFI with OD and 28" tires to a carb'd .030 over bored performance engine, no OD, and 32" all terrains and saw no change (14 MPG). When I switched to 32" mud tires I dropped down to 10-11 MPG. What gears and transmission do you have? This can be a major killer in MPG as well as how many miles on the fuel system. To be honest, you would want to lower the truck to decrease the air turbulence underneath. These turbulence create drag the reduces MPG. If you want to level it still I would narrow the tires go to a highway five rib style tire, put an air dam on the bottom of the bumper (or plastic skid plate the bottom of the frame), use a bed cap, and be easy on the skinny pedal.

 

[FordGuy100]

I wish they made a 235-95 or 245-85. (they might actualy make the 245-85 but if they do its not popular). Skinny and tall

 

[dgr]

I wish they made a 235-95 or 245-85. (they might actualy make the 245-85 but if they do its not popular). Skinny and tall

I wish 255/85 were not so expensive and hard to find locally.

 

[tanman_2006]

I have a 85 regular cab 2wd and i want to figure out how to put a leveling kit on it and i want to put a bigger tire size on the back to try and get a little higher top speed as far as cruising... i only tow a race car that weighs about 2200 lbs and a 16ft trailer so its really nothing but i daily drive it and want to level it and put a bigger tire and better wheel on it.... any suggestions

It depends on your gear ratio, if you have an OD trans, and if you want better mpg in town or on the highway.

4.10's and no OD then you need to go 255/85 OR TALLER
4.10's and OD 255/85 is still the best option but 235/85 is good
3.55 or 3.73 w/ OD then 235/85 is about as tall as i would go
3.55 or 3.73 w/ no od then 235/85 and 255/85 will work fine (should put you at nearly the same cruise RPM as the 4.10 w/ OD)

Tall tires in town will kill your MPG in town because it takes more power to get them rolling. Short tires on the highway of course cause high RPM.

Call Treadwright and see if you can get a 255/85R16 Load E. Their tread pattern is the same as a BFG AT. Most 255/85's come in MT tread

Personally I run 235/85's on my trucks because of the lack of 255/85's out there and i like to be able to find tires in emergency. I run HT's in the front and AT's in the rear.

On a 2wd run a 235/85 in rear and 235/75(or 80) in front and it reduces rolling resist and weight on the front end.

Fuel econ is all about getting RPM's where you need them, cutting weight, and lowering resistance.

 

[IDIDieselJohn]

255/85 won't be any better than 235/85, sure they might be taller.. but they add more rolling resistance!


Best of both would be 235/85 witch is the stock size on these trucks anyways. Or even better 215/85 if you wanna reduce your highway speeds.

 

[tanman_2006]

255/85 won't be any better than 235/85, sure they might be taller.. but they add more rolling resistance!


Best of both would be 235/85 witch is the stock size on these trucks anyways. Or even better 215/85 if you wanna reduce your highway speeds.

With 4.10's turning a 255/85 is no problem, just that they only come in mud terrain. An A/T recap would help that.

I like the 235/85's and will always recomend them as a good all around compromise. 215's are SHORT like 29-30" tires comprared to 235's that are a hair <32" or 255's that are a ~33"

 

[DragRag]

Cooper has an a/t 255/85, I only see it around in 8 ply though. I haul to heavy for 8 ply though.

 

[dgr]

Cooper has an a/t 255/85, I only see it around in 8 ply though. I haul to heavy for 8 ply though.

You look at the M55s?

 

[DragRag]

Ya, I looked at those. I've decided on the bfg km2 mud tire, parting with the money though has me bocking a bit though.

 

[tanman_2006]

A bfg KM2 MT 10ply shell with a treadwright recap would be nice.

 

[DragRag]

Ya, looked, they didn't have any. Km2 255 are hard to find.

 

[tanman_2006]

I would call them, some guys i know have called and requested they find a specific set and they did their best to accomodate. I had 4 10 ply KM2 255's that i trashed and wished I woulda kept now.