7 Facts about Spare Tires

January 27, 2012

Many of us take spare tires for granted, but some drivers might like to know about these items and what they may or may not be doing in the wheel well or trunk of the vehicle.

  1. Replacement Spare Tires Are Full-Size Tires - A standard replacement spare tire has identical sizing to the tires that are already on the vehicle. Some drivers buy another single and use the spare to replace part of a front or back set of tires when they become insufficient for travel.
  2. Many Compact Spare Tires Are "Limited Use" - Smaller spare tires known as donuts or compact spares are often made for short-term travel. They are engineered to be safe on the vehicle, but over long distances, they may cause bad wear patterns and serious road safety issues. This issue points to the larger idea that car owners should always have matching sets of tires when possible. Matching tread patterns and identical amounts of tread will help you get more miles out of your tires, and spend less money over time.
  3. Spare Tires Can Bring Down the MPG of a Vehicle - Carrying around a full-size replacement spare tire, or even a compact spare, can have an effect on the MPG or miles per gallon that the vehicle gets. One reason that companies designed the compact spare tires was to minimize the load on the vehicle over time. It helps to buy spare tires according to the lightest option (a compact spare rather than full size, if possible), to avoid dragging around more than what's necessary.
  4. Some Replacement Spare Tires Are Not the Same as a Regular Tire - Although as mentioned above, a lot of vehicles carry a conventional fifth tire as a spare, in some cases, the factory direct spare actually has a lighter construction, and may not be suitable for long-term use. It's a good idea to check the manual before trying to replace a regular tire with a full-size spare.
  5. Some Spare Tire Types Have Become Obsolete - You'll probably never see a folding spare tire, but yesterday's vehicles sometimes had a small spare that was inflatable, in order to save space inside the vehicle. as tires became more and more a heavy-duty part of the vehicle, some of these types of spares were deemed unsafe by many drivers.
  6. Some Vehicles Don't Need Spare Tires - Today there is a new tire technology known as tubeless tire design, where tires don't conventionally run flat. Additional layers within the tire help keep them buoyant even when they strike obstacles like nails or screws. For newer vehicles, it makes sense to look into this tire technology, which will make a lot of traditional spare tire use and tire repairs obsolete.
  7. Many Spare Tires Need to be Checked for Tire Pressure - A full-size replacement spare tire is the same as any other tire. Drivers need to check tire pressure often to make sure that these tires are not underinflated, which can lead to road safety issues.

Consider the above when you're using your next spare tire for getting somewhere fast.