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

[Herbie]

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.

 

[IdaSHO]

If it ain't broken....

Seriously, unless you are looking to fix something, or gain something, stick with what's working.

IMO the only place a good LT really shines compared to a P-metric will be tread depth & sidewall strength, both of which make it more suitable for off road as it provides more puncture resistance.
If you stick primarily to paved and good dirt/gravel roads, and are not having tire problems, by all means.... stick with what works.

 

[tacollie]

If you haven't had issues then I wouldn't move to LTs. I ran them on Tacoma. I got pretty good at plugging tires including sidewalls so I stepped up to LTs. Now my plug kit just takes up room.

 

[buellconvert]

I am of the same opinion as others, if it ain't broke kinda logic. As far as being hard on front suspension components, really anything from GM in the truck and van line has that unfortunate reputation and from my experience it's an earned reputation. My 95 Silverado, 99 Silverado and now my 2016 Silverado have all been hard on and eaten through their share of frontend components, I've just recently had to replace both upper control arms on my 2016 Silverado with less that 62000 miles. So if you've had good luck running those tires and you're doing really well on keeping the frontend in great shape, I wouldn't switch it up at all.

Sent from my moto e6 using Tapatalk

 

[sideburns]

Everyone considering putting LT tires on a vehicle with P metric tires should read the "Load & Inflation Table Application Guide" from Toyo, Pg11 bit in red quoted below for the TL;DR. Especially pertinent to those running at GVWR who need the full load capacity of their tires.

WARNING! Please note that size-for-size, LT-metric tires require higher air pressures to carry equivalent loads of P-metric tires and that any failure to adjust air pressure to achieve the vehicle’s load requirements will result in tire fatigue and eventual tire failure due to excessive heat build-up. Due to the higher PSI requirements of LT-metric tires they may not be suitable for replacing O.E. P-metric tires because of the ride harshness that results from higher PSI requirements.

 

[Herbie]

Good reminder, sideburns.

I was aware of the concepts, but it is critical to remind anyone who may be reading this!

That said, when I search for such tables, none ever list the OEM tire size and pressure combination that GM put on my door placard: 215/70-16 @ 38psi (most charts top out at 35 or so)

 

[ExpoMike]

I have to mimic the "if it ain't broke, don't fix it" which completely goes against my current job's idea of "if it ain't broke, let's break it"....

 

[Deleted member 9101]

All LT tires would do is rob you of performance, cost you a few MPGs, and ride like crap.

 

[WOODY2]

All LT tires would do is rob you of performance, cost you a few MPGs, and ride like crap.

You forgot $ too.

 

[IdaSHO]

An LT should last longer, as the tread depth is deeper and the compound is typically harder, so the cost is probably close to a wash in most cases.

 

[billiebob]

P-Metric tires often have awesome warranties and mileage guarantees, not so with LT tires.
Size for size P-Metric tires are also less expensive and better riding.

 

[Deleted member 9101]

An LT should last longer, as the tread depth is deeper and the compound is typically harder, so the cost is probably close to a wash in most cases.

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

 

[mep1811]

Based on your driving and the fact the P metric tires work for you I's stick with what works.

 

[WOODY2]

Sounds like the Ayes have it?

 

[rruff]

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.

Heavy tires are not going to wear out your suspension components, but if the tires you've been using have worked fine, I see no reason to go LT. The P series will give you better MPGs.