To 33" tire owners

[Sinjin]

Just wondering how much you inflate your tires to onroad, and also what you air them down to when you hit the trails.
On mine i think the recommended psi is 60, that sounds a little high or is it not?
Thanks,

 

[Paul B.]

I have 33 BFG Mud-Terrains 12.50 and I usually air up my tires at 28 lbs. for onroad use. I get very good wear at this presssure. On offroad use I usually air down to 15lb.
I find if I go any lower then 15, my tires will lose the bead on the rim under stress tire conditions. I know others will go as low as 10lb. It also depends on what type of off road surface you plan on driving on. Sandy beach surfaces you will want to go fairly low like 10lb.

Paul B.
Modified 4x4 XLT 4-door

 

[SteveVB]

Rod

I dont have 33's but do have larger after market tires. The sidewall inflation is just a max load at what ever psi- most people confuse that with inflation pressure. 60 psi is way way too high. I would start with the pressure recommended on the door label, and work from there. Since you are running a larger tire the pressure needed to support the vehicle should be lower than with the smaller tire.

A line of chalk across the tire will tell you if the tread is making contact with the road. For the best braking and handling on the road you want the highest pressure that will give you the most tread in contact with the road. If the chalk line wears away evenly then raise the pressure a couple of pounds till it lifts the outside of the tread then pick the previous inflation pressure to run. If the chalk on the outside of the tread is still there you need to lower the pressure and try it again.

Or you could forget the whole thing and just run the door sticker pressure. Always go by the sticker on the door not the print on the tire- the tire markings are max pressures for a stated load and Explorers wont get anywhere near the max loads for most decent tires.

FWIW with 31 /10.50s I run 25 psi front and rear with no load, on road trips with a load I run 35 rear and 32 front. Offroad depending I run 12-15 in sandy stuff and 20-25 on dirt trails.

Sorry so long mayy be more info than you want -I get carried away

 

[Tekeman]

To anyone running 33s. What have you done about a spare. Can you modify underneath any way to squeeze one in? Do you just do without. I'm not interested in a custom mount behind the tailgate or the roof, if it were gonna be suggested. Keeping a spare in the garage isn't the best idea, but it may have to be. And just throw a couple cans of fix-o-flat in the truck to get me home in an emergency.

 

[Paul B.]

Tekeman, their is no way to put a 33 under the truck where the stock spare is. Most people like myself have a tire carrier setup on the rear bumper. FixOFlat cans won't do you any good if you get a big sidewall cut. For that you might want to look into a product called Safety Seal, the ultimate tubeless tire repair kit.

Paul B.
Modified 91 XLT 4x4 4-door

 

[mattadams]

I agree, I wish I could get that sucker under there but no such luck... anyways, I've got the Mickey Thompson Baja Belted HP tires, 33x12.5. They're more of an all-terrain tire. I usually keep them at about 25-30 psi for on-road and off-road I can take them down anywhere from about 8 to about 15. 8 gets a little low, I've heard some people have taken them down to 4 or 5. I know the Baja Claws you can run with about 1-2 psi.

 

[Maniak]

I don't think you are going to get a 33" tire under there.. We barely fit a 32x11.50 Ko tire under there.. The only way we got it to fit was to use 10psi in the tire. I looked at modifying things to make it fit better but if the tire was any farther forward the rear diff would hit it during compression (it is pretty darn close already)..

 

[Paul Gagnon]

I have a set of 33x12.50 Thornbirds and the same size in Wrangler AT/S. I run both sets of tires at 28-30lbs on the street. The Thornbirds I take down to 6-7lbs off road and I haven't taken the Goodyears off road yet.

 

[rpenner54]

I got 33" BFG Muds and I go anywhere from 25lbs-33lbs on road depending on how I want it to ride. Off-road I usually go 9-15lbs depending on how fast I can get to all the tires once I start them deflating.

 

[Tom Wilk]

Ryan, you're right on the money WRT how you intend to drive. I know that the chalk trick works well for determining the ideal pressure for treadwear (at least driving in a straight line), but somewhat higher pressures will help in cornering and will reduce rolling resistance, at the expense of ride comfort and carrying capacity (though I don't really worry too much about that with my tires, since they are rated way above the weight of the truck). There's a lot of variables to consider and your own driving habits are one of them.

For the record, I keep my tires between 28 and 32 pounds on the road, and have had them around 20 psi on the trail. I'll probably go a bit lower on the trail next time, but I'm not as experienced at it as many here are.