Is a physical model better than the netkar's Pacejka-type model ? In my mind netkar has the most advanced tire simulation and has the best "feel".Its the only sim that going outside of the tarmac over grass and dirt feels as it should feel and when you go back on track the car feels as it should feel with accumulated dirt over the tires for a while untile the tires "clean themselves" .A simiral tire model would make Rfactor 2 the end of all sims...
Lets look at the trend in tyre models.
LFS has used a physical model for some time.
Forza 3 has a physical model
NFS Shift has a physical model
iRacing have anounced they are working on a physical model to replace their empirical model
ISI have anounced they are replacing rFactor's empirical model with a physical model
I suspect Codies have a physical model - the tyres sertainly visually deform during cornering like LFS.
I think NetKar Pro moved to a physical model with v1.1
So the trend is very firmly away from empirical models to physical models. That doesn't mean physical models are perfect. LFS has had one improvement to its physical tyre model and another major overhaul is being worked on.
As most sims (and games which some might not consider hardcore sims like Forza 3 and NFS Shift) are moving or have moved to a physical model then the answer would appear to be it is better. However, such models can still be flawed. The early LFS tyres (which use a physical model) seemed wierd to me and were improved in a patch, but even these are still being worked on as they didn't prove realistic when used with the forthcoming VW Sirocco.
You can simulate dirt on a tyre without needing a physical model.
The weakness with rFactor2 as a sim will be its reliance on mods (though the supplied content does look like it will be much better than rF1). It doesn't matter how good the physics engine is, if the modder doesn't understand the physics engine and doesn't have accurate data to use in the physics engine then the results will be flawed.