Am I nuts for considering sticking with P-metric tire?

[IdaSHO]

Part of the reason that I went with a P rated tire instead of an LT was the longer warranty.

I run Toyo AT2, and even being a big LT it has a 65k mile treadwear warranty.
Though I don't buy tires for warranty reasons, or even treadwear.

I buy the best tire for my application. And my personal experience is that Toyo is it.

Again.... stick with what works.

 

[Herbie]

Heavy tires are not going to wear out your suspension components

On a fullsize truck, maybe not. But a set of 30" BFG TAs is literally more than double the unsprung weight of the factory wheel/tire package. Couple that with the already less-than-ideal idler arm geometry that gets further compromised by the lift that we all have to use to get more than a 29" tire, and it's a concern that we can't quite mitigate all the effects of that much mass bashing around at the end of too-small components. In the Astro/Safari circles we refer to the vans as "Soccer Duty", (vs Heavy Duty) because that seemed to have been the target market for the vans. (Don't get me started on the wimpy diff choices, etc.)

Lots of compromises to be sure, but OTOH my 4x4 conversion cost me $500 and a single afternoon in the driveway.

Thanks for the reassurances, everyone. Still not decided which path I will take, but I feel a bit less concerned I was considering something dumb.

 

[Zuber]

If you NEVER go off-pavement, P tires are probably ok. But, even on a good gravel road P tires don't have good impact resistance. I've blown out two P tires on a rather smooth rock impact. They had a 4" split along the cord, not fixable. The P tires also handled terrible, felt like the SUV had balloons for tires. The outside edges would wear very quickly.

Going to a 6-ply D rated LT tire really tightened up the handling and extended tire wear from tire roll while cornering. I could tell when they rolled over a pea, but it was far from uncomfortable.

 

[F350joe]

Years and years ago i got two flats on the mohave road. Been running E or LT rated tires ever since and have not had a single flat. I like to feel the road so the stiffer sidewalls does not bother me. Go with a skinny LT tire if you are worried about MPG. I think it sort of depends where you are. Out west we have sharp rocks, cactus and what not on roads that you can go pretty fast down. Puncture threat might not be as high if some other areas. Getting a flat does sort of ruin an offroad trip. If you only have one spare you have to stress out the rest of the trip or hit town for another spare.

 

[BigSwede]

I run C-rated LT tires. E is way overkill IMO.

 

[Kmrtnsn]

I run C-rated LT tires. E is way overkill IMO.

Until you airdown to 8-12psi., then you understand the difference.

 

[roving1]

Remember E rated tires can't be aired down effectively and the sidewalls have no flex. They are also too heavy to move without locomotive levels of torque. The internet says so...so it must be true


P metric tires have no real margin for error. Pretty much the first bad thing they experience they have a pretty good chance of failing. Plus as was mentioned they are so horribly balloony at street pressure.

 

[BigSwede]

Until you airdown to 8-12psi., then you understand the difference.

I understand just fine, since I have been wheeling for 20 years. These days I don't go below 15 since I have factory aluminum wheels.

 

[Kevin Wells]

Hey all. Tried to search but either I'm using the wrong terms or running into the short strings limits of the search-engine.

I'm due to replace the tires on our rig. I've got a size that works, with lots of choices, but I've got some very specific considerations that have me considering continuing to use a passenger/p-metric tire rather than "upgrading" to an LT tire. Please let me know if I'm nuts, but bear the following in mind:

• 2003 Astro Van w/ pop-top, westy-style camper conversion, running very close to the GVWR of 6100lbs
• All GM OEM underneath (4x4 conversion via parts-swapping NP233), stock axles regeared to 4.10 for the previously chosen 245/70-16 tire (29.7")
• I've had good success with the current tires: Yokohama Geolandar G012s. Yoko sold both P-metric and LT versions of this tire, which complicates collecting anecdotal "data", but mine are passenger tires: 35lbs each, 2094lbs weight rating
• Only replacing tires due to age, they never let me down and the wear performance was good enough for our needs (with 5-tire rotation scheme)
• Usage: 70% highway, 25% FS road/sand tracks, 5% more technical scrambling over rocks, etc. (by distance travelled)
• MOST IMPORTANT: AWD and 4x4 Astro/Safaris have a bit of a reputation for being hard on front-suspension components. Idler arms, ball joints, etc. My van has had ZERO problems in this area. I theorize this is partly to preventative maintenance, but also because my p-metric tires are significantly lighter than same-sized LT tires. Everyone I know with an Astro that's eating idler arms is running bigger/heavier tire packages than me.

Given that I've been happy with the performance of the current tires, I'm having a hard time justifying making a big move away from what has been working. I'm trying to respect the collective wisdom and keep considering LT tires, but I'm concerned that such an "upgrade" is one of those steps that will actually generate future problems down the road. The van handles well, the suspension is working well, and I more-or-less have all the ground clearance and traction I need for the places I'm driving.

As a concession towards toughness, and given that I'm more knowledgeable about tire loads now than I was when I bought the last set of tires, I will most likely at least step up to an XL-rated passenger tire to add some headroom to the tire-load without a huge weight penalty (~37 lbs, 2400lb rating), but I remain unconvinced that I need an E-rated LT tire for this rig. (Lightest I've found in this size is 43-44lbs which I believe may shorten the life of the front-end components.)

So, change my mind if you can, but anybody coming to this conversation with anecdotes about 8500+lb full-size rigs better bring their own grains of salt.

Hey Herbie,
What did you end up going with? Since my van will have more off road than soccer dad duties, I was inclined to find a some sort of 30" LT . Had planned on some snazzy new wheels, but I see you stuck with stock. Would you reccommend that?

 

[Herbie]

Hey Herbie,
What did you end up going with? Since my van will have more off road than soccer dad duties, I was inclined to find a some sort of 30" LT . Had planned on some snazzy new wheels, but I see you stuck with stock. Would you reccommend that?

Stayed w/ P-metric. I'm going to keep running 'em until they let me down - I'm just not prepared to take the weight penalty until I know I need to. (Plus the wear warranty, overall price, etc. was hard to turn down.)

Regarding wheels - the OEM aluminum wheels are sturdy enough for the half-ton trucks (even those with the HD/high-payload options), and are a good fit for the bigger brakes on the 2003+ vans, so I saw no reason to spend any money on something aftermarket that would probably be heavier and might not fit perfectly. Same philosophy as the tires, basically - I'll run 'em until they give me a reason to change.

 

[nemobuscaptain]

So, change my mind if you can, but anybody coming to this conversation with anecdotes about 8500+lb full-size rigs better bring their own grains of salt.

Sounds like youve already made up your mind.

I have no experience w fullsize camper rigs. I do however have experience w VW Westies since the 80s. Id never run a nonreinforced or LDR C tire.

You dont say where you are. I lived in AZ when I did most of my offroading and camping. I offroaded w work alot also, mostlt in fullsize rigs. I really question your 70/25/5 numbers. If you did that much offroading, you would know why rugged sidewalls are important off the road.

I also have some experience w Astros. Back in the day I was a medic (80s and early 90s) On our days off we'd pickup shifts w a nonemergency ambulance, some of which were, no kidding, just Astros w basically an O2 cylinder, a BLS bag and a cot. Those things had P rated tires to and had terrible problems w suspensions, transmissions brakes and electrical. They werent heavy. May have even weighed less than stock bc Im sure those alum. cots weight less than two bench seats.

You may have just gotten a good one, the parts are better now or who knows what. I seriously doubt the difference in using passenger car tures had the slightest thing to do with it.

you say the passenger car tires have done fine for you. that sounds to me a lot like more of a mall vehicle and very little off-road. there's nothing wrong with that . I've driven around with safari racks on vehicles that never actually got off the road much. and knobby tires are in my redneck DNA.

 

[(none)]

Run P-metric tires and enjoy. I ran my stock Hankooks all over the trails in colorado with 0 issues. Aired down to 20psi, rocks, snow, mud, they did great. The only tires i have gotten flats with were a D-rated mud tire (stick in the sidewall) and i got a screw in the tread of a kO2 that replaced the Hankooks.

 

[Kmrtnsn]

On a fullsize truck, maybe not. But a set of 30" BFG TAs is literally more than double the unsprung weight of the factory wheel/tire package. Couple that with the already less-than-ideal idler arm geometry that gets further compromised by the lift that we all have to use to get more than a 29" tire, and it's a concern that we can't quite mitigate all the effects of that much mass bashing around at the end of too-small components. In the Astro/Safari circles we refer to the vans as "Soccer Duty", (vs Heavy Duty) because that seemed to have been the target market for the vans. (Don't get me started on the wimpy diff choices, etc.)

Lots of compromises to be sure, but OTOH my 4x4 conversion cost me $500 and a single afternoon in the driveway.

Thanks for the reassurances, everyone. Still not decided which path I will take, but I feel a bit less concerned I was considering something dumb.

Pretty sure the entire Astro van front suspension was cribbed from the GM half-ton pickups, providing a simple path to a nearly unlimited supply of replacement and upgrade parts.

 

[Buddha.]

I thought the Astro had more in common with the S10’s

 

[Todd780]

Pretty sure the entire Astro van front suspension was cribbed from the GM half-ton pickups, providing a simple path to a nearly unlimited supply of replacement and upgrade parts.

I thought the Astro had more in common with the S10’s

Yes, I thought it was S10's as well?