Car manufacturers are stealthily eliminating spare tires from many vehicles, often without notice to the consumer, to reduce weight and increase gas mileage.
Buried in the trunk in oft-reduced space once reserved for spare tires is a small tire repair kit can equipped with a gooey sealant that may or may not repair the flat tire and may cost the vehicle owner additional money. One in every seven cars sold today does not have a spare tire and many car buyers don’t check for a spare tire when buying a new car and they are not proactively told one doesn’t exist.
Car manufacturers maintain the tire repair kit reduces the weight of the car by 20-40 pounds to improve gas mileage and conform to federal Corporate Average Fuel Economy (CAFE) standards, currently 29.7 mpg and increasing to 35.5 mpg by 2016.
They typically improve mileage only marginally.
AAA recommends everyone buying a new – or used – car check the trunk for a spare tire and learn what the ramifications are if it has been replaced by a tire sealant kit. If sealant is used, the car should be driven no faster than 45 miles per hour and typically no farther than 50 miles.
If there is room for a spare tire, AAA recommends buying one because sealant won’t work on a blowout or a flat in the sidewall or tread slash larger than one-quarter of an inch.
Eliminating spare tires help reduce the cost of the vehicle and can increase trunk space.
However, tires that have used the sealant may not be repairable, require an extra cost to scrape out the sealant before repair and may damage the tire pressure-monitoring gauge, requiring replacement.
While some drivers will continue to drive on tires repaired with sealant beyond the recommended distance and speed, the more the tire is driven on, the more compacted the sealant becomes, making repair more difficult and costly.
Cleaning the sealant from a tire costs between $50-$80; replacing and resetting the tire pressure monitor can range from $60 to $100.
The tire repair kits utilize a pressurized sealant and inflator applied through the valve stem of the tire. If the puncture wound is too big, the tire won’t inflate. The vehicle must be driven to distribute the sealant to the tire interior, thus blocking the leak.
Manufacturers with some models without a spare tire include Acura, Aston Martin, Audi, BMW, Cadillac, Chevrolet, Chrysler, Dodge, Ford, GM, Honda, Hyundai, Jaguar, Lexus, Lotus, Mazda, Mercedes, Mini, Nissan, Pontiac, Porsche, Saturn, Scion, Smart, Toyota, Volkswagen and Volvo.
Some of the above models use run-flat tires that are able to function for a reasonable distance after being damaged. Run-flat tires typically provide a rougher ride and are one-third more expensive than standard tires.
Buyers should always check for a spare tire when buying a new car. If a buyer notices a vehicle without a spare tire, they should review their owner’s manual to be informed and prevent panic or delay when suffering a flat tire. Tire repair kits have a date and should be replaced every five years or after usage. Sealant becomes less effective with age.
If you carry a spare tire, AAA Carolinas advises that you check periodically (at least annually) to be sure it is properly inflated. For more detailed information, visit AAA.com/Auto and click on the Tools and Tips section for more tire maintenance tips.
View video footage from our press conference on missing spare tires.