What size tires?

[BigMike]

I currently have 245's on my truck and am looking to replace them soon. I'd like to put larger tires on. I have a 3. 55 rear end. How much larger can I go without significantly affecting my ratio?

 

[BIG BOB]

BigMike,

I'm running 285/75R16's, and I'm going to 305/70R16's. They are the same diameter as the 285's but 1" wider. With the 285's and 305's you have about a 7. 8% difference in ratio compared to the 245's. If you are driving 60 MPH with the 285's you are actually going 64. 7 MPH.



After looking at you signature, it appears that I am running a lot more power, so I don't notice the difference that much.



I would think 265's would be a good tire for you. You could go to 285's or 305's, but you would notice a big difference in low end power.



Here is a Tire Size Caculator that may help you make your decision.

 

[Diesel Dan]

Hello BigMike,



My truck never made it home with the stock 265/75/16's . My local tire guy had a set of 295/75/16 BFG AT ko's ready for me. There was no problem going up 3 sizes with power on a stock not-broken-in-yet motor w/3. 54's. It is only when i went up 2 more sizes to 315/75/16's did i notice the motor not performing as well. with your VA and exhaust you should be able to go w/285/75/16 and be good to go. Besides the truck will look much better, have much better ground clearance and be much happier when you dump those roller skate wheels. Also there will be no clearance issues w/285's no rubbing on anything.



Best regards



DD

 

[Chipstien]

Big Mike, remeber that the highest you can go and still have a accurate speedo is 265/75 R16. You would need to have a dealer set the tire size in the computer though. Being that you have a stick I would say that you could run 285 with no ill effects. Auto is a different story.

 

[Chipstien]

FWIW, I realize that there are add-on devices that can correct your speedo but the price they are going for make it a "very" uneccesary part.

 

[GFoley]

I ran a 255/85/16 on mine for a while. Difference was 10% in the odometer/speedometer. They stayed inside the fenders and never rubbed. They were almost 3" taller than the 245 OEMs.



With all of that said, I also see that you pull a 5er. You'll have to get some help from those that tow, but how much taller can you raise the bed and still not have any interference?

FWIW, the BFG MTs were LRD tires, something like 3,000# at 50 or 60 psi.



Wheel width should also be considered with the changes you are contemplating. I could have SQUEEZED the 355s on the OEM 6. 5" whell but was afraid of wearing the center tread too quickly. They were mounted on 8" wheels.

 

[BigMike]

GFoley, Luckily I have plenty of clearance with my 5er hooked up, but that's is something I'll consider in my purchase. If I go 285's, I'll be raising the rear at least an inch. I'm also going to check with dealer about having odometer/speedometer recalibrated.

 

[Chipstien]

The dealer can only calibrate up to a 265/75 r 16. They cannot go any larger. Been there, done that.

 

[Challenger-II]

I just went from 265's to 285's on a stock truck w/auto and I am not happy with the drop in performance! I can feel the difference. Looks like time to put on an EZ. Hope it helps. Does anyone know if the Truspeed correction unit helps with transmission shift points?

 

[athompson]

I went with the 315s

I didn't notice any difference in performance over the 265s. In fact, I gained over 1 mpg. I didn't bother with the TruSpeed since, at just short of 10% difference, I can calculate my correct speed in my head. Also, I didn't need it to shift my transmission at the right time, since I do that all by myself.

 

[BillGotthelf]

I replaced my 245's with 285-65-16's. They are considered a street tire but I work in the sand and they work pretty good. Tires are the same circumference as the stockers but are 4" wider and grip like glue. They fit on 8" wheels.

 

[Gordon Maney]

I have been really happy with my 255-85 tires. It offers some good height, yet does not stick out the sides and throw rock up the side of the body. Plus, the narrower profile works great in the snow.



When these wear out, I will get the same size again.

 

[Got Smoke?]

Well I have a 12 Valve that's BOMBed now, but was stone stock when I bought it.



I bought it with 33x12. 50xR16. 5 tires on it and it had no trouble going down the hwy with 3. 55 gears.



Now I still have 33/16. 5's but I also have a few "mods" so I have no trouble crusing down the hwy @ 70-75mph

 

[onestackdram]

Now I still have 33/16. 5's but I also have a few "mods" so I have no trouble crusing down the hwy @ 70-75mph

Except your gonna go deaf from the noice of those TWO new toys you installed.



Russell

 

[cosborne]

I went from 265's to 285's last week. I had Cooper's on the truck but damaged a sidewall beyond repair. It was a great excuse to move up a size anyway. I went with Dunlop AT Radial Rovers, 285/75/16 load range D. After 200 miles I took the truck back to Sears to rebalance the tires because of vibration. They told me they were ALL out of balance... so either the first guy to balance them didn't know what he was doing... or... ... Well, they seem to fine now... I'm running 55 psi while I've been empty and I really like the ride... . The Coopers seem to ride a bit stiffer even though they were the same load range... .



Just my 2 cents... . I should throw in a thanks to Harry at Piers for getting me my Edge EZ... just came in the mail today!!!

 

[onestackdram]

I went from 265's to 285's last week. I had Cooper's on the truck but damaged a sidewall beyond repair. It was a great excuse to move up a size anyway.

But you did remember to go up a size on atleast the other three tires right. . LOL

 

[cosborne]

I was wondering why it was so cheap



and actually the wife did say "So can't we just get one tire to replace the damaged one?" I said yea... but they don't have any that size in stock right now