Road Tires: Different Capacities for same model?

I know zero about tires, but need to buy a set soon.

'98 'burb.

One thing I definitely want is capacity above and beyond the mandated minimum for the vehicle in question - having blown a sidewall a few years ago...

I don't want off-road tires because the only off-road driving I do is in sand and I'd rather not have the noise that my current Toyos make.

Consumer Reports likes Goodyear's 'Assurance TripleTred' and Michelin's "X Radial"... so I'll probably buy one of those lacking other information. Wet and dry braking are at the top of my list. Tread life is at the bottom. Noise is somewhere in the middle.

So - what am I looking for capacity-wise? How so I express/identify/confirm same?

Reply to
(PeteCresswell)
Loading thread data ...

I have had real good luck with Michelins on my 89 burb that I bought new. Get some LT (load range "C" if it is a 1500) and run they near max pressure and you will not have any problems with sidewalls and if you do that and get a smooth tread you will also pick up a mile or two per gallon on highway with it from reduced rolling resistance.

----------------- The SnoMan

formatting link

Reply to
SnoMan

There are different load-ratings for different size Michelin tires of the same "model". The LT 245-series tires were all E-rated and had higher load capacity and maximum inflation pressure than the C-rated 265-series tires did. That was the case with the XCH4 tires I ran on my '88 and it was the same for the LTX tires I have on my '00 Silverado now. With the 245's I could pump them up to 80 psi and really "stiffen up" the sidewalls when pulling heavy trailers... but the 265's are only rated to

50 psi. The load rating difference was similar... 3042 lbs versus 2470 lbs per tire? E-rated 265-series LTX MS tires were supposedly "not available" when I bought my last set of tires... although they are shown on the Michelin site now:
formatting link
There's an interesting footnote on that page regarding the use of "P" (passenger car) size tires instead of "LT" (light truck) size tires on trucks: "Passenger sizes used in Light Truck/SUV applications have reduced load capacity. This will differ from the maximum load branded on the tire sidewall." I'm pretty happy with the LTX MS but I was disappointed with the LTX AT that I had before... mainly due to the shorter tread life. David
Reply to
David Courtney

On Fri, 14 Jul 2006 13:23:17 -0500, "David Courtney" wrote: WHythe fixation on E range tires on what may be a 1500 burb where about 50 PSI is the the max safe pressure on wheel rims? Anyone running 80 PSI on l those rims is asking from trouble big time. I strongly suspect that the poster has a 1500 burb too to begin with. If so LT or load "C" tires will do just fine at or near max pressure. Most tire that suffer sidewall problem are usually because they do not have enough pressure for the load and the sidewall is flexing more and running hotter than it should and weakening it with time until it seperates.

----------------- The SnoMan

formatting link

Reply to
SnoMan

Per SnoMan:

That is correct - and I'm not into running tires at any more than the recommended pressures.

Reply to
(PeteCresswell)

If you are using passanger type tirs, 35 PSI does not cut it well on the heavy vehicle. LT/ Load Range C tires are rated 50 PSI and will help your concerns a lot and they roll good too. (your stock rims will handle 50PSI)

----------------- The SnoMan

formatting link

Reply to
SnoMan

I didn't have any problems with the wheels on my 1/2-ton Sportside after

480,000+ miles of running mostly load range E tires. You don't have to run them at 80 psi (I usually didn't) because the truck isn't that heavy. In my experience, the extra ply and higher "ply-rating" of the E range tires also means they also have stiffer sidewalls, so they resist the swaying motion of a trailer better and are more pleasant to tow with... even at lower inflation pressures. I did have the option of pumping them up to 80 psi (I have done at least 100 times) which really stiffens them up and helps a lot if you're pulling a big enclosed trailer that acts like a "sail" behind the truck. I will take load range E tires over load range C tires whenever I can get them, but it's not a fixation... just my preference after driving more than a million miles in light trucks. David

Reply to
David Courtney

Are you saying that you cannot put only 50 PSI in a E range tire? If Pete has the saem rims I do (Aluminum 5 spoke, 6 bolt) then the rims are rated for 55 PSI. C range tires are fine for the 1500 series, but many tires (or at least in stock) do not come in C range, only E range. Does that mean Pete can't buy an E range tire and only inflate to 50 PSI, at which inflation is rated at 1,500 pounds more than the GVW of Pete's Suburban?

Reply to
Mike Dobony

Is this on a 1/2 ton or 3/4 or 1 ton? The half ton wheels are most likely only rated to 55 PSI and you are risking an exploded rim if you inflate to

80 PSI. Check the total load capacity of the tires and compare that to the GVW of the truck. You might be suprised to find that even the C range tires have more capacity than your truck is capable of!

Mike D.

Reply to
Mike Dobony

Per Mike Dobony:

Half-ton I guess - It's a 1500 series.

No interest at all in running more than 50 PSI - or even more than 40. The only issue I see between C and E, then, is whether E can be run at the lower pressures and perform as designed.

Knowing nothing, my kneejerk is to go with the "C" rating... OTOH, in my book stronger sidewalls are better - if only because I'd imagine they're less susceptible to damage from curbing.

Reply to
(PeteCresswell)

Per SnoMan:

I think the LTXs are what I'm going to get. Only loose end in my mind is "C" vs "E" - based solely on safety considerations. If "E" works at 38-40 PSI as the designers intended I might go for "E" just for the added resistance to curbing.

Reply to
(PeteCresswell)

It will give a slightly stiffer ride than a C rated tire, but it will not hurt it to run it lower. Pressure needed is determined by load.

Reply to
Mike Dobony

I would not as it will waste fuel at this pressure and stiffer sidewall will consume more energy when flexing more at lower pressure and stiffen ride as well. "C" tires are a lot tuffer than standard passanger type tires and even "E" do not have 10 plys in side wall either unless they are bias ply tires. Lots of passange tires just have one ply is side wall and "C" radials have 2 or 3 (depending on brand)BF Goodrich A/T's have a very strong sidewall and it is one of its trademarks too so to speak. It is your money but you will likely have shortenr sidewall life from flex issues with a "E" run at 40 PSI vs a "C" run as same pressure and a "E" will not carry anymore weight than a "C" will at same pressure and since your rims are only rated 50 PSI, whu waste money on 80 PSI tires that you do not need? More it not always better hear.

----------------- The SnoMan

formatting link

Reply to
SnoMan

Barking up the wrong tree here because sidewall impact resistance is determine by thing other than load range on a radial. On a old bias ply tire, a 10 play tire is 10 ply in tread and sidewall. I use 10 ply rated bias ply studded snow tires on my plow trucks in winter and not only do they provide great traction, they also are about indestructable to curbing. Not that you want these tires but is shows the difference on tire design vs ply rating.

----------------- The SnoMan

formatting link

Reply to
SnoMan

Actaully it will in pocket book (MPG) and possible tire life from extra flexing. It is REALY siily to buy 80 PSI tires to run at 40 PSI.

----------------- The SnoMan

formatting link

Reply to
SnoMan

Per SnoMan:

That makes it pretty simple: it'll be "C".

Thanks.

Reply to
(PeteCresswell)

There's nothing "silly" about buying a tire for reasons other than it's maximum load rating or maximum inflation pressure. If you run a C-rated tire and an E-rated tire of the same size at the same pressure... the E-rated tire will have less sidewall flex. Stiffer sidewalls with less flex have lower rolling resistance and give slightly better mileage than softer sidewalls. "For example, DuPont has suggested the use of aramid fibers to replace steel cords and monofilament replacement of current polyester multifilament to modify stiffness. Aramid yams have been available for over a decade, and their use can cut rolling resistance by 5 percent. Polyamide monofilament have been recently introduced that improve the tire sidewall stiffness and reduce rolling resistance by about 5 percent."

formatting link
My experience with E-rated Michelin light truck tires (XCH4 and LTX MS) is that the tread is worn out between 83K and 88K miles... but I have never had any sort of sidewall failure. Also, lower inflation pressures increase the maximum stresses on the rim... not the other way around. "The results revealed that the inflation pressure does affect stress in the wheel," said Stearns. "Higher stresses were found at lower pressures. That may seem counter-intuitive unless you consider that the pressure helps to maintain the wheel's round shape. At lower pressures, the weight of the car deflects the wheel into an oval shape which results in higher stresses."
formatting link
David

"SnoMan" wrote in message news: snipped-for-privacy@4ax.com...

Reply to
David Courtney

Per David Courtney:

Anybody besides me think that tires are worn out well before the tread thickness is below the statutory minimum?

Seems to me like other things in the tire wear besides the treads.

I base that on how much better the vehicle handles after the tires are replaced at, say, 30 or 35k miles when the treads are still passing state inspection with no problem.

Reply to
(PeteCresswell)

So for a 3/4 ton Suburban that recommends 50 psi in the front and 80 in the rear. Does that mean the owner should buy C rated tires for the front and E rated tires for the rear or should the owner overinflate the front tires to

80 psi and destroy cornering and braking ability in order to reduce your imaginary extra flex? Why limit choices to only E rated tires? I had a hard time finding C rated tires and only got them because they had a desirable tred pattern (slightly more aggressive than the stock tires) and were on sale. Several of the desirable tires were only available in E rating or P-metric. Due to instant need I had to get what was immediatly availabe. E series tires would have been perfectly acceptable. BTW, if he has the same rims I do they are rated to 55 PSI. The steel rims should be able to handle much more.
Reply to
Mike Dobony

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.