When I ask Diego Villa how many used tires he's rated in the year and a half he’s been our reigning used tire expert here at Combine World, he has to pause. Diego, who’s worked at Combine World in various shop and yard positions over seven years (and now is sharing his expertise on the sales counter as well) grins and looks up, calculating.

His best guess? "Over 200."

He estimates probably 70% of the tires that come in attached to salvage units are in good enough condition to be resold, a perk of buying (and taking on trade) higher-quality parts machines. Combine World also picks up lots of good quality tires from OEM manufacturers and dealers to supplement its line of great-value, factory-direct new tires.

Diego’s 18-month total includes tires for combines, tractors, sprayers, seeders, and a variety of other truck and ag equipment. He’s examined 380/90R50s (14.9x50s) from a John Deere 7200R row crop tractor, 900/60R32s (35.5Lx32s) and 800/70R38s (30.5x38) from combines, down to tiny tires like 7.5x15s. Diego also inspects all of the packer tires and gangs we receive for seeding salvage, which he doesn’t count towards his total.

He points out to me that many our sales staff at the counter have also done stints being the designated Appraiser-of-Tires, and so would also be very familiar with our system. After all, at Combine World, we prefer to have written-down processes, rather than storing all our knowledge inside one person’s head. We need to be able to continue evaluating tires in the unlikely (but theoretically possible) event that Diego wins the LottoMax next week and doesn’t feel like coming in. We have a systematic approach that’s been tinkered with and improved over the years.

So how do we rate our used tires?

As you may have noticed on our website, our tires are given an overall ranking out of 10. Any used tire you buy from us will vary in how much life it has left—and that’s something we’re upfront about.

  Charlie Smith, president of Combine World, who outlines our used tire rating system below

Combine World founder and president Charlie Smith describes our system below. 

How do you rate used tires?

  • 9/10 is like new. It will still have the little rubber knobbles on the treads of the tire.
  • 8/10 will have slight tread wear, and no visible hairline cracks - likely less than 5 years old.
  • 7/10, the tread may be worn down 25%, and there may be small cracks or stubble checking in the face of the tire. Sidewalls should have no cracks, but in some cases may have very small hairline cracks.
  • 6/10 is a useable tire, but will be showing more significant wear, moderate face cracking and possibly some sidewall cracks. It may last for a few years, you never know, but this tire is showing fairly substantial wear and tear.
  • 5/10 holds air and that is about it. More of an emergency solution when you cannot get a good one or you really don’t need a good tire. We do not consider anything poorer than this suitable for use.

Combine World has, at this writing, nearly 140 used tires for sale on our website. Check them out here.