285/75r17 or 315/70r17 KO2 (1 Viewer)

[ga12r1]

So I’m looking to replace the 285/75/r17 Cooper ST MAXX that are currently on my 2000 LX with KO2s.

I’m trying to make a decision between the 315/70/17 or the 285/75/17 size.

I’m not worried about the fitment of either size, I’m more concerned with performance. I’m regearing to 4.88s in two weeks and will be running dissent front and rear bumpers, a arb drawer system, sliders, and a front runner rack. So I have a some extra weight to deal with.

I’ll also be pulling a travel trailer with dry weight of 3400lbs and a GVWR of 4500lbs quite often, and probably twice a year out to Colorado/Utah from Georgia.

I know the KO2s generally run on the smaller side and I’m afraid if I go back to a 285/75/17 in a KO2 it won’t give me enough height for the 4.88s? So I’m thinking 315/70/17 may be right for the gears? Maybe closer in height to the 285/75/17 coopers I have now? More like a 34.

Throwing the travel trailer in the mix complicates things though. I want to be able to pull it effectively, and I don’t want the 315s to mess that up by maybe being too tall for pulling the Travel Trailer? Stopping wise the LX has new brakes all around and Brake Controller and trailer brakes.

Here are the specs on the Cooper’s I have now and also the KO2s I’m looking at. Both the KO2s also weigh less then my current coopers. What do you guys think?

 

[OffRoadScott]

I went with the 325/75-16 KO2 on my FZJ80 and love them. The ride is so much smoother, I do rub though thanks to shot factory suspension. But overall I love them.

 

[05JLX470]

Are you running aftermarket wheels or spacers with OEM wheels. Sounds like either way you have some pinch weld mod. With them both being pretty equal in height, I say go with the 315 for a little beefier look......

 

[ga12r1]

Are you running aftermarket wheels or spacers with OEM wheels. Sounds like either way you have some pinch weld mod. With them both being pretty equal in height, I say go with the 315 for a little beefier look......

Yeah, I’m not concerned with the fitment. I’m running Rockwarriors and 1.25” spacers with pinch weld mod. I think 315s will fit fine, I’m just worried about performance pulling the trailer. I think about pulling it 2000 miles across the country at 65 mph and I worry that the 315s might be too much and the 285/75 too little with the 4.88s.

 

[OffRoadScott]

Yeah, I’m not concerned with the fitment. I’m running Rockwarriors and 1.25” spacers with pinch weld mod. I think 315s will fit fine, I’m just worried about performance pulling the trailer. I think about pulling it 2000 miles across the country at 65 mph and I worry that the 315s might be too much and the 285/75 too little with the 4.88s.

If you are thinking about re-gearing I wouldn't waste the money. There are several 80's out here in AZ that are running 35's and never re-geared. Taking their advice I did not and I notice very little if any power loss.

 

[ga12r1]

If you are thinking about re-gearing I wouldn't waste the money. There are several 80's out here in AZ that are running 35's and never re-geared. Taking their advice I did not and I notice very little if any power loss.

I couldn’t tell when I went from 33s to 35s on my 80 either. It was still a pig. I think it takes a lot of work to make an 80 feel any slower.

 

[05JLX470]

Yeah, I’m not concerned with the fitment. I’m running Rockwarriors and 1.25” spacers with pinch weld mod. I think 315s will fit fine, I’m just worried about performance pulling the trailer. I think about pulling it 2000 miles across the country at 65 mph and I worry that the 315s might be too much and the 285/75 too little with the 4.88s.

I think 4:88s is a great idea going up that size in tire especially with your 4 spd trans. You are still going to be at a higher RPM than stock and our 4.7 will like that. Hope this helps.....

 

[fireball]

Have you towed your trailer much yet?

My 99 runs 295/75/16s and 4.88s and it doesn't do a great job with our 2700# trailer/camper. We live in hilly central PA and I have lots of heavy crap bolted onto and into the truck.

I'd stick to the smaller size tire.

 

[fireball]

And I'd strongly consider setting up your 06 for tow duties. The vvt and 5spd will be a huge improvement for towing.

 

[ga12r1]

Yeah, I’ve been towing it with my 06 and it does fairly well sitting on 305/65/18s. When we go to HIHs and out west we want to take the LX because it’s built for the trails though.

I’m actually thinking of moving to a 200 for my daily and for towing the TT most places, but I will still want to use the LX for towing when there will be trail duty.

 

[bwell]

I would see how it does with your current tires once you get the new gears installed and break in period completed.

Then based off of how you feel it pulls go up or keep the same size. I bet it will be a nice improvement.

In my experience pulling multiple moving trailers across the country, and towing my other old beater car(about 5200lbs with trailer) across multiple states also. As long as you keep in mind these aren't 2500 series big diesel trucks and treat them as such they can do the job satisfactorily, not necessarily good or great.

Now the 200 series is in a whole different realm in my opinion if you want to compare the two, night and day difference in power, and extra "rated" 2k lbs of towing capacity. Our lx570 drinks fuel noticably more, I enjoy driving it more but prefer the ride of my 100 vs. Ahc(might be better with a system flush which I need to do when I get back home), but I looked for about 6 months before I settled on a lx570 vs waiting and searching for a comparable mileage LC in my budget.

Just my $.02

 

[bozncsurf]

@Steelman had an 06 with 315 ko2s on RW to give you an idea on sizing, I believe @fireball ran a similar setup.

Tundra wheels on 100 series photo thread

The ko2s (and all bfgs) definitely run smaller.

In the thread above @Steelman prioves this point by measuring an un-mounted 315/70r17 ko2 next to an un-mounted Nitto 295/70r18.

The 295/70r18 was bigger in every aspect.

Because it's a dedicated trail rig, i would take a look at the KM3 mud coming out. Not that aggressive looking - hoping these have great road manners.

GL - post pics

*edited for relevancy.

 

[REZARF]

With 4.88's I bet you'll be fine with the bigger tires. However, the 33's run really well on a 100, but I think the 4.88's will make you want a bit more tire. Either way with the 4 speed you are going to be hunting for the right gear while towing, just the nature of the beast.

 

[ga12r1]

Thanks for all of the replies guys.

I’ve found a set of 2017 Ford Raptor takeoffs with 315 KO2s locally for $500. Tires only have 15k on them and I figure I can sell the wheels for $400. So I guess it will be the 315s. It’s just a deal I can’t pass up.

That being said, is anyone interested in some 2017 raptor wheels?

I’ll also be putting my five 285/75/17 Cooper ST MAXX in the classifieds as soon as I get them off. They only have 10k miles on them and are like new.

 

[Bomar]

I run 285/75/17 Toyo AT2.....love the tire got 65k miles on last set and still had 6/32 of tread left