155/80R17 is a temporary spare tire size that’s meant to assist drivers after a puncture or blowout. 155/80R17 tires can typically be stored within a vehicle thanks to their compact size, and tires like the Firestone Tempa Spare (Radial), Falken FK-090, and Bridgestone Tempa Spare TRR2 are great options if you need a spare tire; just be sure to swap it out as soon as possible and before you’ve driven 50 miles.