It’s a tough time to be in the automotive business right now since the economy appears to be headed for a prolonged recession. That’s good news for the automotive aftermarket as drivers will be more likely to repair their old vehicles and forego new car purchases. However, it can also be bad news because when the dollars tighten in the average household, vehicle maintenance becomes one of the first cuts in the budget so dealers go back into the business of “fixing” cars.

But vehicle owners aren’t the only ones feeling the pinch as sales are plummeting for most car manufacturers. Each company is looking for a competitive edge on everything from fuel mileage to cargo space and both of those factors can be affected by the extended mobility device. Extended mobility is simply the ability to operate the vehicle after a tire suffers a complete air pressure loss rendering it flat and useless. Up until a few years ago, the solution was a spare tire mounted somewhere on the vehicle that could be installed with the portable scissors jack and lug wrench that was conveniently tucked in some corner of the passenger compartment or trunk. This approach rarely failed and continues to be the primary method for achieving extended mobility.

In the battle to remain competitive in the new car market, an increasingly important factor is fuel economy. Engineers constantly search for ways to save a pound here and a pound there in order to lighten the vehicle. Reducing the weight also helps car makers comply with federal corporate average fuel economy (CAFÉ) requirements so getting rid of the spare tire would also provide additional room for people and other interior features. Eliminating the “donut” or full-size spare tire and still providing extended mobility is hardly a new concept as run-flat tires have been around for decades, but up until this point, they are still limited to specialty and luxury vehicles.

One significant advantage of the run-flat approach is that if the tire were to suffer a major cut or impact break, the vehicle is still able to operate for a limited distance for a limited time so it has extended mobility. When run-flats were the “in thing” a few years ago, we can all remember the commercials where the hole was drilled in the sidewall or the tire ran over a rake and then kept going. Whether the extended mobility is made possible by reinforced sidewalls or an insert that wraps around the rim, the vehicle can still be moved to a service provider regardless of the location or size of the injury.

A new, and perhaps problematic, trend is the move to eliminate the spare on vehicles that do not have runflat tires. This solution to extended mobility consists of a device for inflating the tire (a compressor that plugs into the cigarette lighter), and a product that plugs the hole up to a quarter inch in the tread area (a liquid sealant material). Since these vehicles use standard tires that are not designed to operate without air pressure or with insufficient air pressure for any period of time at any distance, this could become a serious issue for retailers for a wide variety of reasons.

First and foremost, the chemical composition of a liquid plugging agent must be such that it cannot freeze. In order to accomplish this, a number of different compounds can be used and some of them may be petroleum based. Unfortunately, we’ll never have all of the information on all of the compounds, but we are aware that at least one of them includes ethylene glycol, or the main ingredient in anti-freeze. When the innerliner of a tire is exposed to a petrochemical substance, a wide variety of problems can develop, among them severe cracking that can lead to separations and tire failures.

But the solution to the problem is not to simply rinse out the inside of the tire. Once again, the chemical composition of the liquid material is probably such that it should not be washed down the drain or storm sewer. Every state has different Environmental Protection Agency (EPA) regulations regarding the proper disposal of things like used motor oil, anti-freeze, and transmission fluid so now we can add a few more to the list. That is going to be great news to the companies who operate in more than one state.

Then there’s the issue of how the material is going to interact with the various tire repair materials on the innerliner and in the injury. Cleaning the innerliner with pre-buff cleaner will become more important than ever and nobody really knows how a rubber stem is going to react inside the injury channel if any residue is still present. It’s not possible for the tire repair material manufacturers to test every substance on every type of injury in every type of tire so that’s another area that will likely be exploited by an informed plaintiff’s attorney.

And since this approach is present as original equipment on new vehicles that include tire pressure monitoring systems (TPMS), there is also some concern about the long-term effects on sensors and the internalelectronics. One of the sensor manufacturers hastested some aftermarket substances and found them to be less than favorable for sensor life and performance. TIA’s Senior ATS Instructor Matt White field-tested one substance over the port for the internal sensorelectronics and reported that it hardened and plugged the hole very quickly and effectively. He cleaned it off and the sensor was still working according to his scan tools, but that’s not the same as one that has been inside an operating tire for miles.

Speaking of miles, we also don’t know how well this new approach to extended mobility is going to work. You would like to think that after experiencing a flat tire and applying the sealant before re-inflating it, the average driver would get it checked out as soon as possible. Even the yellow dashboard light that sort of looks like a tire with an exclamation point would be an additional reminder, but you know that people have been ignoring dashboard lights for decades. You’re a realist so you ask yourself, how many drivers are going to give the suspect tire a kick for the first few days and then figure the problem has been miraculously
solved? These tires could run for hundreds, if not thousands, of miles with the puncturing object still in place and the sealant effectively stopping any leaks around it. It’s just a matter of time before the imminent belt separation reminds the driver that the light on their dashboard means they still have a nail in a tire.

Emergency spares, runflat tires, and full-size spares also have limited extended mobility and will eventually fail to the point where they are inoperable, sometimes catastrophically. But the driver is still aware that they must address the situation within the first 50 to 100 miles because the “donut” or run-flat is only going to last so long. While full-size spares appear to have unlimited extended mobility, they are often the most dangerous because too many people believe they can take a new tire that has been strapped under the vehicle for nine years and install it like it was new. Then they put some air in their “new” tire, stow the flat tire back in its place, and then drive off hoping they don’t get another flat until the other three tires wear out. Then they can put that nine-yearold “not so new” tire back under the vehicle until they need it again for a few thousand miles. That nine-year-old tire will probably get them to the next tire service provider at less than highway speed, but most people think they’ve won the lottery because they don’t have to buy a tire. This has lead to serious and fatal accidents that have cost millions to defend and settle.

Most importantly, there is the tire manufacturer to think about because they are the ones spending all the money on lawsuits caused by negligent tire maintenance. Almost all of them have original equipment fitments and some of them have fitments on vehicles that include the new approach to extended mobility. The Rubber Manufacturers Association (RMA) has not weighed in on the situation because they are not in universal agreement on what do after the material has been applied. Some are leaning toward a position
where the tire is scrap and cannot be repaired, others favor repairing the tire as long as the existing guidelines for size, location, and installation procedures are followed, but no tire company has taken an official position as far as we know.

The only thing that is certain is the tire dealer is going to be the one who is once again stuck in the middle. Since we don’t have all of the information from every tire company, we’re starting by raising awareness of the issue and offering a few suggestions for retail tire dealers who are concerned about the liability associated with repairing tires that have been exposed to internal compounds that are used to plug leaks.

• Check with all of your tire suppliers to get whatever information you can regarding the repairability of these tires.

• Educate the consumer on the potential long-term affects of short-term underinflation. If they have driven on the tire for an extended time, the best and safest practice would be to replace the tire.

• If you decide to go ahead with the repair, it will be difficult to get the inside of the tire clean. Also keep in mind that you must abide by state regulations for disposal of the extended mobility compound.

• During the repair process, the injury channel must be as clean as possible while maintaining the quarter-inch limit in the crown area.

• Always make sure you write down the ID number of the sensor that was exposed to the material. If it fails 10,000 miles later, you’ll be able to prove it wasn’t your fault.

But perhaps the most troubling aspect of this approach to extended mobility in new vehicles is that it will make on-thewheel repairs even more attractive to the uneducated motorist. If the sealant material cannot stop the leak, then replacing the penetrating object with a few string plugs might be the next option. Even scarier yet, the sealant material will remain inside the tire indefinitely after the on-the-wheel repair. A recent RMA study of 14,000 tires revealed that only 12 percent of the scrap tires they inspected were properly repaired. And that’s not 12 percent of 14,000 because only 17 percent of the 14,000 were repaired, or approximately 2400 tires. Of the 2400 tires that were repaired, only 12 percent, or 288 were performed properly under RMA and TIA guidelines. People have been plugging tires for decades, but none of them will be able to account for the effects of this new approach to extended mobility. They will probably find out in a court room.

At a time when consumers should be paying more attention to their tires than ever, the vehicle manufacturers are clearly not in the tire business. I’m sure they calculated the odds of a tire being completely disabled and fully understand that the customer is going to be upset when they find out for the first time that they do not have an emergency spare on the side of a remote road or highway. It may cost them a few towing bills, but right now the focus is on selling cars. And they all speak about the limits of extended mobility and the fact that the driver should have the tire serviced as soon as possible. After all, if a driver chooses to ignore the warnings on the dashboard and in the owner’s manual causing the tire to fail, they’ll blame it on the tire.

But if these motorists heed the warning and make it to the tire dealer, then someone’s business or paycheck could be on the line when it comes to making the call on whether to repair or replace the tire. Before making that decision, all of the factors must be considered, and in this case, there are still a lot of unknowns, not to mention the glaring lack of consensus among the manufacturers.

Until that matter is resolved, TIA members who are confronted with these tires will not have to shoot from the
hip when it comes to repairability of the new approach for extended mobility. We are very fortunate to have forged some solid relationships at the manufacturing level because it makes it easier to ensure that our members are aware of any developments that may impact their liability. How a company decides to handle these tires is entirely up to them, so we want to make sure that TIA members have the best information before a customer shows up in front of your business with a flat tire that contains these compounds and requests a repair. TTI