In KenKunen's physics v. 1 the rain tyres are good in rain gravel&tarmac and also quite good in dry tarmac&gravel, so in rallying rain tyres are safe choice. The dry gravel tyres are very slippery in rain gravel, so with those tyres you will lose a lot. With tarmac tyres in rain tarmac, you can drive with many cars about same results than with rain tyres. I have always used tarmac tyres, because it was logical choiche. I thought the RT designers meant the rain tyres to be rain gravel tyres. And I also drive with tarmac tyres with my own car when it is a rainy day.
The snow is changed to some kind of syrup in the new physics, so it needs different (unrealistic) driving style. The snow properties should've edited/consulted by a person who has driven in real snow. The original allowed cutting with high speeds that was not actually like real life, but the original was nearly realistic, the physics needed only minor adjustment and that with only the deep snow (not with the light snow in many areas - where the car does not get stuck in RL!). Damn, I get mad because of this unrealism. Sweden in winter is now almost totally destroyed. I hope this will be edited soon. Or the new version will be a new rally, with changed textures (Fantasy Rally in Syrup).
So, there is still some work to be done. The physics cannot never be perfect. ATM, the physics in this area are pretty good in 80% of the surfaces. The tyre selection could be done so, that we have more selectable tyres in fully same type tracks all ice&snow tracks, all gravel, all tarmac (then the tyrenames should be changed to others - Pirelli, Michelin,... ;-)). There is different snow tyres and ice tyres in real life, I think. Well, maybe it was not the case in those old days. And in Kenya, the 3 tyres from left could be harder gravel, softer gravel, rain gravel, mud, rain mud. It should be possible to edit the physics so, to get this kind of functionality. Can the menus edited too?
So, in general the KenKunen tyre physics are good, but those above mentioned few unlogical tyre choises and unrealistic snow makes this usefull only for some special racecing. If we want more realism, we need to adjust those problems away. We are going to good direction, with all physics changes, afterall. I hope that only these minor flaws will be corrected. If also the grass and other tracksside materials behaviour will be changed to similar as snow, it would make RT more unrealistic in all surfaces.
1. We make trackside surfaces similar to snow in all other rallies too, because in real life those are as slow as soft/low snow. E.g. in Kenya, your car should get stuck as easily as it gets stuck in Sweden. And all of the trackside grass should be equal to this snow too.
OR2. We make the snow more realistic. This is easy, just make it about middle of the original and current version.
OR3. We make the 2. and make also all of the other stages a bit slower than originals (but not as in 1.) in the road side areas.
The option 1. makes all surfaces to be logically at same level, making all unrealistic, but it is still better, than having 20% of stages different physics logic than the rest of them. The option 2. is better, because it makes snow realistic and it is easiest to implement. The option 3. is best. Thatway we would get more realistic optimal driving lines and styles for many cars. If cars could also get damages maybe 50-100% more in all damage happenings (jumps, hits, full-throttle driving and sliding), it could make driving also more realistic.