P-metric tires on SUVs and light trucks continue to grow in number and size: But vehicle owners still need guidance on issues like load and psi

March 1, 2004

"Replacement follows OE." This oft-repeated tire industry maxim certainly applies to P-metric tires on light trucks and sport-utility vehicles. "P-metric is the overwhelming choice for original equipment manufacturers," says John Pecoraro, Cooper Tire & Rubber Co. product segment manager, house brands. "Most of the light trucks and virtually all of the SUVs I'm seeing are coming with P-metric tires." (In the photo, a Pirelli Tire North America 25-inch Pirelli Scorpion Zero is mounted on a new Hummer H2 at last year's International Tire Expo.)

Combined, nearly 80% of all OE tires on light trucks and SUVs are P-metric, according to Modern Tire Dealer research. And that number is expected to increase as more light trucks and SUVs hit the market.

What's the attraction?

Consumer demand is driving the proliferation of P-metric tires on small pickup trucks and SUVs, say tire manufacturers. Most SUV owners want the amenities of upscale cars, and pickup owners have started to follow suit.

"Just look at what's available in the 2004 pickups and truck-based crossovers," says Pecoraro. Vehicles like the Cadillac Escalade, Chevy Avalanche, Dodge Ram 1500 Laramie, Ford F-150 Lariat and GMC Sierra STL "are as luxurious as any car. It's not grandpa's old farm truck anymore."

Light truck and SUV manufacturers are using more P-metric tires for additional reasons, says John Soule, Michelin brand light truck category manager for Michelin North America Inc.

1. P-metrics cost less than LT tires. P-metrics have lower tread depths, therefore they use less rubber. They also contain less polyester in their carcasses and smaller steel cables or, in some cases, lower density of steel in the belts. "P-metrics don't need to be over-engineered," he says.

2. Fuel economy. "A P-metric tire is lighter than an LT," and provides less rolling resistance, says Soule.

"P-metrics work fine in the vast majority of light-duty pickup and SUV applications," says Pecoraro. "That's their appeal and that's why they are OE."

That's also the reason why most light truck and SUV owners who have P-metric tires on their vehicles choose P-metrics as replacements, he adds. "There is little benefit in moving from (an OE) P-metric tire to an LT tire unless the application calls for it."

15 going on 17 (and higher)

Sizing remains at the forefront of P-metric light truck/SUV tire trends. The most popular overall P-metric size is P235/75R15, the majority of which were fitted on light truck tires last year, according to MTD statistics.

Another popular P-metric size for light truck and SUV applications is P265/75R16, says Bill Vanderwater, consumer products manager, sales and engineering, for Bridgestone/Firestone North American Tire LLC. The LT version of the 265/75R16 is the most popular domestic replacement LT size and the second most popular OE LT size.

"All of the things we're seeing at OE (indicate) that diameters are moving up to 17 inches," he adds.

Eight million 17-inch P-metric tires were sold industry-wide at the OE level last year, according to Mark Cherveny, Goodyear Tire & Rubber Co. product manager for Goodyear light truck tires. "In 2001, it was a little more than three million."

Eighteen-inch P-metric OE tires "were virtually non-existent" in 2001, with about 3,000 units shipped that year, says Cherveny. "In 2003, it went (up) to 640,000 units." OEM spec sheets hint that even larger P-metric tires will become more commonplace. For example, the 2004 Dodge Ram -- the third best-selling vehicle in the United States -- comes with 20- and 22-inch rims as options.

Shouldering the burden

Most consumers don't know the difference between P-metric tires and LT tires, according to tiremakers. Those who do tend to use their vehicles in heavy-duty, off-road applications like construction or rock-crawling, says Cooper's Pecoraro. They realize that LT tires are sturdier and more resistant to punctures and other hazards. But the average soccer mom who uses the family SUV to haul groceries or the pickup owner who piles mulch into his bed for the once-a-year home landscaping job is usually not as cognizant, especially when it comes to issues like load.

The responsibility of informing vehicle owners about load and proper air pressure falls on the tire dealer's shoulders, says Cherveny. "They are the ones on the firing line, dealing with customers one-on-one."

Dealers also should apply their expertise when customers want to change from P-metric to LT or vice versa. For example, Goodyear does not recommend that vehicles originally equipped with LT tires switch over to P-metric tires. "We assume the OEM picked LT tires for a reason," usually their robust construction, says the company. Going from P-metric to LT is permissible, according to Goodyear.

"But you need to do research. Sometimes sizes aren't always the same" and the air pressure on an LT to carry the same load as a P-metric will be different, says Cherveny. "We tell (customers) to look in their owner's manual or on the door jamb" to find out the correct inflation pressure, not the tire's sidewall. "The sidewall lists the (tire's) maximum psi pressure to carry the maximum load."

There always will be a place for LT tires on pickup trucks, according to tiremakers. Michelin's Soule believes the percentage of OE P-metrics on those vehicles "has tapped out. Certain applications demand an LT tire -- for example, vehicles used for off-road events like a Jeep Rubicon. And LT tires, of course, play an important role on commercial pickup trucks, because they offer more durability."

Consumer education is critical at the replacement level, says Riccardo Cichi, Pirelli Tire North America Inc. vice president of sales and marketing. "The end user doesn't know the difference between P-metric and LT. They assume if they're buying a Cadillac Escalade, for example, they're buying the right tire."

"It's a question of finding out what the customer plans to do with his or her vehicle," says Gary Keyt, service manager for Ronda Tire Inc. in Grand Rapids, Mich. Ronda Tire's P-metric customers include "everyone from farmers using 4x4s to suburbanites whose idea of off-roading is limited to the gravel in their driveways.

"We try to assess what the (vehicle) owner's needs are," says Keyt. "A lot of times I've found if you listen to your customer, they'll be more happy with the product -- rather than you force-feeding it to them."

Jody Smith, general manager of Koehler Tire & Supply Co. Inc. in Madison, Ind., feels the same way. His dealership is located next to the Ohio River "and we have lots of people who pull boats and are generally overloading their P-metric tires. We ask them, 'What are you using the vehicle for?' Just because you're taking P-metric tires off doesn't mean you have to put them back on."

Smith says his customers, as a rule, are receptive to his advice. "Most of them listen to me."

Given the plethora of replacement tires at a dealer's disposal, "you can usually come up with (a tire) that's even better than what the manufacturer recommends," says Keyt.