Fun fact: did you know we typically test over 80 new cars and trucks every year? And over time we’ve noticed that full-sized spare tires were going the way of the VCR, replaced with temporary spare tires--commonly called “donuts.”
Aside from the fairly obvious smaller appearance, you can also identify a temporary spare by the “T” designation that appears in front of the size shown on the sidewall of the tire.
These diminutive tires operate at higher pressure to provide the load capacity of a full-sized tire. They save room and more importantly save some weight, which helps improve a vehicle’s overall fuel economy.
But now we’re seeing the days of the temporary tire dwindling, with more cars eliminating the spare altogether (along with the tools to change a spare).
So what’s a motorist to do? To deal with the "spareless" car, manufacturers are equipping some models with run-flat tires, which when deflated offer limited mobility--typically 50 miles at speeds less than 55 mph. BMW, for example, has been a big proponent of run-flat tires. We also see these types on sporty cars with limited space. We’ve written extensively about Toyota Sienna AWD models using run-flats as well. Early generations of run-flat tires rode stiffly and wore-out quickly. They’ve gotten better, but if your car has run-flats, your replacement tire choice might be limited. Plus, run-flats often cost more than conventional tires.
The other approach manufacturers have taken is to equip cars with a tire repair kit consisting of an air compressor and a canister of sealant.
We started seeing tire sealant kits on some on low-volume cars like Lotus Elise, Pontiac Solstice, and Smart ForTwo--all smaller cars with very limited room. Now we are seeing some more mainstream models come equipped with the space-and-weight-saving sealant kit including Cadillac CTS and SRX, Ford Mustang, Hyundai Elantra, Saab 9-5, and Volvo S60 and C70, to name a few. So it seems as if the tire repair kit isn’t limited to cars with space restrictions any more.
Looking back, we found that only 16 percent all of cars tested since 2005 came with a full-size spare. And few of these cars and trucks actually had an identical replacement; often it was a spare tire on a cheap non-alloy spare wheel or even a different model and size tire than what came on the car. Temporary spare tires account for about 75 percent of the cars we’ve tested during that time, and that includes a small number of collapsible spare tires that have a compressor to inflate prior to installing on the car. With a full-size or temporary spare, all the cars get a jack and hand tools.
Run-flat tires only account for about 4.5 percent the cars we tested.
About 4.5 percent of our tested cars came with a tire repair kit, which works fine if you have the classical small nail puncture in the tread. But if you’re like us, we find most of our flats are caused by sidewall cuts from pothole or curb damage. If this happens to you, then you are out of luck and will need to have a cell phone handy to call a tow truck. (Read about our recent experience: “Hyundai Elantra leaves me flat.”)
Finally, it’s always good to have a roadside emergency plan in place just in case.
Familiarize yourself with what comes with your car: spare tire, tool kit, repair kit, or run-flat tires. Also, if you’re buying a new car, ask if it comes with a spare. Sometimes a spare tire/tool kit can be purchased as a dealer option if your car doesn’t have one as standard equipment. Knowing what your car has beforehand can help you plan accordingly, including bringing your own emergency kit.
Read our take on preparing for a roadside emergency.