Can't say about cars cause I've never owned new car tires, BUT new motorcycle tires YES!!!! VERY MUCH SO A MUST!!!

This is also true when breaking in the side of the tire... slowly leaning more and more till its nice and worn in all over.


(Of course a good burn out will work the rear tire in )

 

In addition to the 'mold release' residue, a lot of brand new tires also have a soap-like coating on them to slow oxidation of the rubber. Takes a fair bit of driving to wear it away, and it can make a small wet piece of asphalt feel like an ice rink.

 

my tire spreadsheet

tires export.pdf

 

we try to scrub in new race tires for a session and then let them sit overnight, it does actually help.

 

at 300 miles, my new kumho tires stop about mid point between the beloved sumitomos $42 tires and how slippery the kumhos were when I first got them.

and if this info saves just one person from having a wreck because of slippery new tires, then this forum, club, site, and the whole internet was worth it.

 

I have these tires on my stock wheels for my '85 FB. Took them out on Buttonwillow before, and will be using them again at Willowsprings this weekend. The grip is good, but with the tall sidewalls on the narrow stock wheels I have be certain that my tire pressures are at the max, or else the side wall flex get really uncomfortable. Transitions in cornering can feel like teetering on a rubber band when the tire pressures are slightly low.

I need a wider rim.

I would really like to goto 15"s and then have a better selection of rubber. I got these through TireRack, but I don't see them on the site anymore. Price was cheap at hell.

 

after 500 miles on the new Kumho's, it turns out they grip very good. the wider sumi's that they replaced gripped better.

so I spoke too soon when I said that the new Kumho's were like driving on ice, they just needed to be broken in that's all.