Sizing up on wheels

[stormlover]

For those of you with heavy vans and e-rated 35" tires: Have you gone 17" and ended up wishing you'd gone with 18s or vice versa?


With a 17" you have more sidewall for airing down off-road but the tire choices are limited. The load ratings are less as well with most being 3195lb at 65psi. The price increase on 5 rims with rubber in 18" is ~$400 but not a deal breaker. Hwy handling is arguably better with the 18s with less sidewall flex. Off-road traction are probably better with a 17. Driving is mostly pavement before off-roading with perhaps a 90/10 ratio. So, looking mainly at Toyo A/TII or the R/T. If I went 18 I would look hard at the Cooper S/T Maxx. I'm not a fan of the BFG KO2 although I like the aggressive look.


I'm about to retrofit with E350 08+ bigger brakes and 14" rotors thus the wheel change. Currently running 315/75/16 Duratracs. The Duratrac has been a good tire in my experience but looking to try something different in a 35. Besides load rating with an 18 there are more options that are a true 35. Thanks for any input.

 

[shenrie]

I was forced to go with 17's when I put the sterling axle in back. I was much happier with 16's for sizing/load rating options and especially pricing. the bigger you go the more expensive crap gets. tires are something the vans eat rapidly. saving that extra cash every time you replace the rubber adds up quick. that and its not like these rigs ride plush. the more sidewall the better imho. handling? well they aren't sports cars. cant expect much in that department period.

ran the 285/75/16 at2's and was happy with them. got about 35k ish on them before they hit the wearbars and replacing. not one flat the entire time and was pleasantly surprised by that especially knowing the abuse I gave them. could have drove them longer, but winter was coming and once they are at the wearbars, they are worthless in the snow.

as you prolly know, no 17" duratrac in the 315/70/17 with an e-rating. currently running 315/70/17 ko2's now. I hear they are going to wear fast from most, but only time will tell. a couple have said they were at 30k and still looked like there was plenty of life left. crossing my fingers I get some longevity from them. wanted duratracs but heard they wear fast as well and needed e-rated for my fat pig.

 

[stormlover]

I think I will be happier with the 17s based simply on looks but hoping to get some 18 opinions. As far as the duratrac goes, my current set (315/75/16) have 40,000 miles on them and still have 10 to 11/32 tread depth. That's impressive on a 10,000lb van but they are not necessarily the cat's meow. They do have some squirm to them, especially under hard braking. Once I hit 20,000 miles or so the ride quality went downhill with noticeably increased noise and wander on the hwy.


One reason I'm thinking of going Toyos is the reportedly stiffer sidewalls. I'm probably over-thinking this but I'm mildly concerned with the lower ratings in the 35" diam 17" tires. Toyo A/T2 or R/T, BFG KO2, Cooper AT3 are all 3195lb max at 65psi. Fully loaded my van is 10,500 lb. One way to do the math is:


The max load on four 17" tires is 12,780lb. Thus, I have 10,500/12,780 of full load. That is about 82% of the max tire ratings. Maybe that's enough of a safety margin maybe not? I've got my family on board so I think hard about running a tire at full capacity. And the load isn't evenly distributed with 4500 over the front axle and closer to 6000 over the rear. Again, I'm probably over-thinking it but it might be enough to make me go 18". I confess I don't like the looks as much and prefer more sidewall with some bulge.