Donuts for Racing?

I went to a local vulcanizing shop during the holidays and overheard two yuppies talking about a spare tire that they brought with them. It was a donut tire that, from what I heard, they purchased from a local used tire store.  My curiosity overtook my manners as I eavesdrop for more talk. One guy asked, "Is this tire good enough for long distances and high speeds? Why did they make this tire narrow and why the yellow paint?" the other guy then added by saying,  "They used it for rear tires in a drag race and it's made in Japan, it should be better than those regular tires that are made in the Philippines or China."

I was about to butt-in and introduce myself before reacting to their queries when my manners told me not to do so. Instead I decided that an article would have a more appropriate way of sharing information.

For those of you who haven't seen one, these donuts are narrow spare tires with painted yellow rims. It's  a type of spare tire that is used as a replacement whenever a vehicle's tire goes flat. These tires/rims come standard in Japanese Domestic Market(JDM) Cars and US brands.

Why the extra narrow design?  The clamor for more baggage space led to the design of this tire. Typically it takes up much less space compared to the regular tire installed on a regular width rim.  Its a space saving measure. But of course, that's not all.  Donut tires are cheaper to manufacture than full size tires and wheels, which translates into more profit for the car makers.

Donut  tires are not made for extended service as the name would suggest. They should not be driven for long distances or speeds more than 60km/h. Why? These tires have so little tread, they don't have the same traction as the regular tire.  The construction of the sidewalls are not fully reinforced  to protect it from "Philippine Potholes" and road imperfections." The tire is, again as the name would suggest, a simple spare tire to bring you to the nearest tire repair shop.

Yes, Japan makes better quality tires than China or the Philippines. But donut tires, whether US or Japanese made, are not comparable to any conventional tire in the market. They are purpose made tires that are far inferior in terms of performance, especially durability and traction, mainly because these tires were designed to bring you to the nearest repair shop.

“Can we use it for racing? My answer is a BIG NO! It's not built for high speeds. These tires have smaller footprints than conventional tires, which translates to less traction. Little traction means poor handling and braking.

And why are the rims yellow? Well, what does yellow mean in the traffic light? What does the yellow flag stand for in racing? Why then is the donut tire rim yellow?