Plus Sizing Tires Without Gear Change?
 

My tires are getting to the point where I'm going to start looking for new tires. I have 265/75-16s on there right now (Pirelli Scorpions). I'm thinking of moving up to 285/75-16s. I'm really happy with the shift points and cruising speed (63mph@1800rpm in OD) and don't want to affect it too much.

WARNING: Type 'A' geek info coming. Read at your own risk!

If my 265's are roughly 31.6" tall and the 285's will be 32.8" tall will result in circumfrences of 99.3" and 103.0" respectively. I know that it's only a 4% difference, but I've seen things change ever-so-slightly and result in a large difference.


I've read that the speedo is a little fast (5-6% if I use the radar speed trailer set up near my house) anyway and 285's are about what it's calibrated for anyway. I'm looking to fill out the wheel well a little better and get a little more rubber to the ground when I'm out in the dirt on weekends.

I'm looking for anybody who has upped to the 285's and kept the 3.73 gears. Did you notice any difference in driving around? Do you find it coming out of overdrive on hills? Are you pleased with the truck's performance (i.e. transmission shifting and power band) after the change?

I'm trying to see if it's worth the money and I'll still be happy or just stay where I'm at and deal with the pizza cutters I have now until I can afford lift/wheels/tires/gears. Plus there aren't too many 'E' rated tires in the 285 size...

Thanks for any info.

Well, i went to 285,s for the same reason, fill those wheel wells and even though its only an inch or two bigger, i like the looks. They are a bigger tire so it takes a little more, not much to get it going throttle wise. Try to get a E rated tire, my D,s are good but i lost the stiffness and tighter handling, otherwise very pleased with them. I got my 373,s and theres a 1-3 mile difference in speedo for me, seems that way but never was clocked. Without my chip on a hp setting and in stock, depending on the grade, it will jump out of OD. My .2 cent, get the 285,s, they look great.

When I went from stock 265's to 285's, My speedo was much closer according to a GPS than stock. Didn't notice any changes in the shifts and it does look much better.

Good info guys. I was wondering the same thing. But what about pulling? Any differance there?

None that I could tell.

What they said. Love my 285's.

Hey SR. I went ti the 285's, and I thought it was shifting alittle more than with the 265's. I tow a 35' fifth wheeler, and actuslly went back to the 265's. I was told that the 285's have a D rating but, are really an E rate. I really liked the 285's but my rig is gettin tired(engine) and until i do some mods, will stick with these. BU1(SCW,FMF)

I ran 285s for a couple of years before going to my current 315s. The truck drove great on the 285s. No issues with shifting. Still does good with 315s.

Take the advice of the others and go with an E load range. When I ran 285s, I ran BFT ATs in an E load range. Pricey but a good tire.

Depending on the tire, the D rated are within about 200lbs of the E rated.

When you're towin' and haulin' those 800lbs and sidewall stiffness can make a difference though...

Still running 3.73 gears with 37's and no issues...

I doubt you will even notice the diffeance.

yeah im also running 37inch tires with 3.73 gears and i still do 70mph on the freeway a little below 2000rpm..........little sluggish to get going though unless you put your foot into it

Depending on the tire is right. I had a set of load range "C" tires (6 P.R. of the antiquated system) that had a weight limit of 3600 lbs. at 25 PSI. Try to find a load range "E" tire with those numbers.


However, just don't subject a "C" or "D" tire to the same sidewall-deflecting forces....or it's bye bye seated bead. There's a reason that letter is there.

Whatever tire you choose, I will try to steer you away from Yokohama Geolandar A/Ts. I install a ton of these tires on customer trucks and the response is always the same...."It feels like the tires are flat. The truck just floats around." The sidewalls, even on the 10 P.R. tires are WEAKER than paper....and the 285s don't come in anything but 8 P.R.

I have ran 285s for the last year and I love they way they make the truck look sadly though I have D-Rated tires. I couldn't tell you about sluggishness I have a DP-Tuner ;).

Thanks for the info...I'll watch out for the Yoko Geo's.

[quote=cleatus12r;6759630

Whatever tire you choose, I will try to steer you away from Yokohama Geolandar A/Ts. I install a ton of these tires on customer trucks and the response is always the same...."It feels like the tires are flat. The truck just floats around." The sidewalls, even on the 10 P.R. tires are WEAKER than paper....and the 285s don't come in anything but 8 P.R.[/quote] I agree with the floating statement on these Yoko,s i got, not a good cornering or handling tire but their holding up ok. I'll defintly go back to my B.S. Revos when these are done, a little pricy but worth it. I had the 265,s and they lasted a long time with great traction and handling.