I have a 1990 7.3L extra cab dually, with a 5 speed and 4.10's in the rear- I will be towing various things, but primarily vehicles on a trailer from West Texas to Louisiana. Lots of hills. Well, it is time for tires. What are the results with the LT215/85-16's Versus the LT235/85-16's on mileage and towing? The joke in my family is that it will get stuck on wet pavement, so I was thinking about going wider, but that also means taller... Thanks in advance!
maruaderx

 

If you want a little lower gears (numerically higher) run the 215s, if you are looking for a little taller gearing go with 235s or 255s. Mileage wise the taller the tire the longer it should last, less revs per mile.

Wider does not have to mean taller, if you dont want pizza cutters look at 245,265,285 /75/16, same height as the relative tire above but wider profile.

I believe your truck will have called for 215/85/16 stock, so with those you will have an accurate speedo (if it matters) also being shorter they will help marginally with the hills (lower effective gear ratio)

 

Get an E load range tire for sure. I would go with the 235 85 16 myself. That's what I run on all of my 4.10 trucks, including an IDI dually. I have run 265 75 16 on an SRW truck - do not know if it will fit a dually (spacing issue in the rear etc). But they are wider, and are pretty much as tall as the 235 85 16 (the height difference is negligible - I ran the same speedo gear with both the 235 and the 265). Anyway good luck man, let me know if you go for the 265 75 16, I'm curious to know if the rears rub against each other on the dually.

Also, if it means anything, 235 85 16 happens to be the factory/original tire specification on my Cab and Chassis 4x4 Dually.

 

I have a feeling that 265's would rub under load...

 

the 265 will porbly rub at 80 psi unloaded

 

I dont know the spacing on the stock wheels, but a buddy of mine is running 285s on his obs dually with no problems. Stock wheels, tires are toyo MTs. At any rate, i dont see 265s rubbing.

And if you run 80 psi in dual tires in the first place, you have more problems than rubbing tires.

 

the joke going on in the family isn't too far wrong from the truth lol.
wider tires would only reduce traction and hurt economy even more.
i would stick with 215/85/16's with the 4.10's.

 

how so?



10 char

 

yup.

He must have spacers. My 235s are as wide as I can go without rubbing under load.

A loaded dually doesn't need 80 psi in the rears. It might need 80 if it was single, but not a dually. As far as the tires are concerned, the dually doesn't have much more load capasity then the srw trucks. It just has more stability.

I'm loving the 235/85R16 Michelins on my dually. The tires fit the wheelwells perfectly and the tires have about 1" of space in the rear.

I don't have any traction problems.

 

i understand that, he just makes it sound like the tire is going to blow up just b/c it is at 80psi on a DRW or something bad like that.

most of the DRW's i have seen are supposed to be at 65psi according to the door sticker.

 

285's WILL NOT fit on any drw with stock wheels and no spacers.

is there any way we could get some pics of the truck running 285's hairy?

 

um.. ill look on facebook, but he live about 240 miles from where i now live. I suppose he could run a spacer or something never thought about that.

As far as 80 in duals, every tire ive ever seen will say something along the lines of rated at x,xxx @80 psi single 70psi dual. Something to do with heat build up in duals.

 

4 tires does not equal double the payload as compared to 2 tires.

It is assumed that neither of the dual on one side will have the same amount of load. Difference in grade, height difference in road surface, potholes, uneven roads and so forth.

I read a good article that explained it better, but I can't find it now.

 

Well, I am looking at this tire really hard-

Kumho Road Venture APT KL51

Great price point, I like Kumhos, and the reviews seem decent...