I have a question about my full size spare. I recently purchased a truck. I have removed the stock street tires which were Bridgestone Dueler H/T 685's in the size of 255/65/R17. I put on all terrain tires. They are Falken Wildpeak A/T's in the size of 265/70/R17's. A little bigger tire that fits fine and looks great. My full-size spare that came with the truck is mounted up underneath the truck and is a Hankook Dynapro H/T in the size of 255/70/R16. Is this spare tire ok to use in case of a flat tire? It's a different size/style of tire. Of course it's going to look weird. But is it fine to put on and drive on for a few miles until I can get the flat repaired? Will it hurt the truck at all? Or should I buy a new spare to mount underneath the truck that is the same size tire as my Falkens?
Thank you for writing in, and great question. First and foremost, it is absolutely fine for you to use your full-sized spare tire when you need it. The slight size difference between the spare and the size of tires you are running right now will not be an issue. By that same logic, if we were not able to use an undersized tire when we get a flat, we wouldn't have compact spare tires for sedans and smaller cars. As a general rule of thumb, you want your truck to be perfectly balanced between all four tires. This allows your tread to wear evenly, keeps your suspension working well, and helps the vehicle drive correctly. You may feel a difference in the way the vehicle drives with an undersized spare tire, but you may not notice at all with a full sized tire that is just slightly smaller. Just try and keep the spare in good condition and only use it for a minimal amount of time.
It will be find to use in the event of a flat, as long as you don't drive on it for long. Most spare tires are smaller than the vehicle's regular tires to save on weight and cost. At least trucks come with spares that are real tires, and not the tiny rubber donuts that often come with cars! A spare tire's job is to get you safey from your breakdown place to a nearby repair facility. Your 255/70/R16 Hankook will do that.