I'm not quite sure if this is already in but it doesn't seem like it. Surely though, when the tyre is dirty, the grains of sand prevent the tyre from actually touching the road as much so it acts as protection. This could make quite a difference because if you clip the sand with a rear wheel and the tail slides out in the next corner your rear tyres get stupidly hot and your whole race is a mess. Just a thought... not really a big thing and it would be difficult to make accurate.

Theoretically it should work like this:
Dirt on tyres = less grip
Less grip = less friction
Less friction = less heat

But I'm going to test this...

Hmmm, testing this isn't that easy.

Was trying a 4 second wheelspin against the wall in the FOX, but both clean and dirty tyres heated up to about 69°C. I don't know if that has any scientific value, though. I only made 6 testruns (3 each) but the temperature was always very close so either

a) it's not modelled, or
b) the difference is minimal, atleast with my testing method

Quote from AndroidXP :

Theoretically it should work like this:
Dirt on tyres = less grip
Less grip = less friction
Less friction = less heat

But I'm going to test this...

Actually, less grip would = MORE friction, ie, you are either sliding a single spot of the tires or spinning the tires creating friction.

But if you have no grip than there's no friction either, atleast that was my train of thought.

But by definition friction is a force, so the more friction, the more force, the more grip.

For me it always felt like the tires are heating up more when they're dirty due to more sliding in the turns... Could be imagination though...

Yeah of course - the question is, does a tyre that is spun x times in a set amount of time with a fixed amount of force pressing it against the road generate the same heat as a dirty one under the same conditions?

Quote from AndroidXP :

Yeah of course - the question is, does a tyre that is spun x times in a set amount of time with a fixed amount of force pressing it against the road generate the same heat as a dirty one under the same conditions?

TO THE BATCAVE!!

Quote from AndroidXP :

Yeah of course - the question is, does a tyre that is spun x times in a set amount of time with a fixed amount of force pressing it against the road generate the same heat as a dirty one under the same conditions?

As I said (maybe not clear enough): I think dirty tires heat up FASTER and they get a lot hotter than "clean" tires when driven under normal racing conditions...

bbman, I think you're talking about how it works in LFS at the moment, whereas Android is talking about Real Life(TM).

Actually, in RL™ I'm pretty sure the dirty tyre would create less heat in a controlled environment but more heat during a race because of the increased sliding/slipping.

What I'm asking is, does the same apply for LFS? Or does slipping the wheel always generate the same amount of heat regardless of how dirty the tyre is?

I'm pretty sure you would generate more heat still on a dirty tyre because you have some more slip, BUT for the same amount of slip a dirty tyre would generate less heat than a clean tyre. I think, however, that LFS's tyre temp increases are slip based and a dirty tyre and a clean tyre generate equal heat increase at the same slip.