treadware rating?

[fast43]

building a 87 truck to race on a 3/8th mile asphalt oval. rules say must be 60 or 70 seires. 14 inch DOT approved with a treadware rating of at least 240. all the ones i've seen in the junk yard around 400. is the higher number a harder tire? any suggestions.

[kyle@tirerack]

The 400 means the tires will have a longer treadwear rating. The higher numbers can be associated with longer wear while the lower numbers would be more in tune with higher performance tires. You'll see the summer tires or competition tires will have much lower numbers but in turn much better grip. The number can be used for reference but isn't consistent from brand to brand. See link on UTQG for more detailed info.