2nd Gen Non-Engine/Transmission New rear end ratio with 285 tires ?

[pete97]

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

 

[Rattler]

Don't worry, you have plenty of grunt to pull the tires. I have ran 285's and 305's with no real problems. Randy

 

[pete97]

Ok, just wanted to make sure. What rear end ratio do you have Rattler?

 

[Rattler]

Same as you, 3. 54. Randy

 

[pete97]

Thanks. I'll let you know what I get. Pete

 

[Rattler]

The reason i stopped running 285's is the set of bfg's that i had ,all seperated at the same time( tread split open) at about 20,000 miles. I was scared to try any more and went to 305's. Randy

 

[pete97]

Are they 305/70/16's I am still not sure what brand tire I will go with. Probably the cheapest I can find in an All Terrian

 

[BILLVO]

In my area the Yokahama Geolanders have become probably the most popular A/T tire sold. I have had 2 sets and like them a lot. The new ones have even more factory siping and more aggressive sidewall tread,looks even better than before.

 

[Rattler]

Yes the 305's were a 70 series. I have since gone back to a 265 to get back to an E rated tire. Randy

 

[Mine Owner]

Dear sir, I have been running 285-75R-16 tires on my ram for 90'000 miles. If I lost any power or performance, I have not noticed. I am loaded most of the time. Loaded to me is 18'000Lbs or more

 

[pete97]

Rattler, do you like the 265's better?

 

[Alphacowboy]

I would say 285 is the cut off for performance... past 285 it does go down, alot if you ask me. They do help "lug" the engine when you first get going, so it spools the turbo, but it definately hurts ya. I have 315's with 3. 55s and I dont like it. Has alot of top end gear, but I miss the low end grunt. I am in the process of a AAM axle swap with 3. 73s, and am excited to see the difference.

 

[pete97]

I'm just stuck between 265's or 285's. I think I should go bigger than the middle.

 

[BILLVO]

Go with the 285. They look better and perform well. The last set of BF Goodrich A/T 285's I got 115k miles from them. But I had them siped when they were new. That was loaded and on a lot of gravel about 30% of the time. You will be really glad if you go 285.

 

[HerbW]

Well guys, We still haven't answered Petes question. This is a question I also wanted to know. With larger tires other than the stock 245s using a 354 rearend, what is the new gear ratio? i know there is a calculation to do this. Does anybody got it? Thanks. Herb

 

[JJanetka]

I was going to get toyo open country a/t's (305/70r16) at $175 each mounted and balanced but my local tire guy talked me into open country m/t's same size for $225 both E rated. I hope I like them.

 

[DZLROKET]

I have 265/70 17's w/4. 10 rear ratio. great off the line but SxxT fuel milage

 

[JKinney]

I was going to get toyo open country a/t's (305/70r16) at $175 each mounted and balanced but my local tire guy talked me into open country m/t's same size for $225 both E rated. I hope I like them.

What did he dislike about the a/ts? Ive been buying my tires from these people http://www.tires-easy.com/start.html

 

[pete97]

I believe that the calulation is Original Tire Diameter/New Tire Diameter X Gear Ratio = New Gear Ratio

Example 30. 5/33. 5 X 3. 54 = a new rear end ratio of 3. 22 This is what my new rear end ratio would be with 285 tires. Is this too high or not. Thanks Pete

 

[pwerwagn]

I run 305/70-16 Nitto Terra Grapplers, Load range E, on mine. Currently they have around 50,000 miles on them and probably have another 15K left on them.

I have 3. 55's in my truck too, with a 5-speed. I tow heavy occasionally (18,000lb trailer weight), Haul my 11' Lance camper, tow the boat, the enclosed trailer, etc. I have never ever regretted running the 305's. FWIW, a 305-70-16 is the same basic height as the 285/75.

Ive also ran 35's on it and didnt notice much difference either.



-Jeff