I have 3.54 rear end now with 245/75/16 tires. I want to change to 285/75/16. I used some calculations I found online and figured my rear end ratio with 265 tires would be around 3.42 and with 285's it would be 3.22. So the question is would the 285's make my ratio too low and will I suffer any performance or pulling lose? Thanks Pete

 

Yes pulling power will suffer. It's dependant on what your usage is and how much you pull as to how it will effect you, but the bottom line is that you are dropping the anchor so to speak by making that change. Your manual trans will help overcome some of the shortfall though.....and you'll be able to cruise 80mph with ease empty.

 

The most I tow is a 2 place snowmobile trailer and firewood from camp. I don't think that is too heave to worry about it. What do you think? Pete

 

With towing that light, and your performance mods, I don't think I'd worry a whole lot.
It won't be the same as with the smaller tires, but still quite acceptable.

 

I switched from 265's to 285's and the difference is very little. I tow 8000k 5r without any problems towing any of the mountain passes around here. Don't worry about it. Phil

 

Thanks for all of the info. I'll probabaly go with 285's then. I would hate to go with 265's and then wish I had gone with 285's.

 

I'm running 40" tires with 3.55's and a 5spd. During the summer I pull my friends ski boat. I have no idea how heavy it is but it has a tandem axle trailer, 302 V8, and max capacity is 9 people. I don't get over 1200* pulling up hills or 1000* flat at 70mph. If I have to go slower I just drop it to 4th and pull it no problem. I also get 17mpg on the highway. (unloaded that is..)

 

That sounds nice BigNasty. I will go with 285's. Just never have a truck with such a low rear end ratio, after the tire change. Pete