Well it differs a lot between different cars.
I drove a usual Opel Vectra A (Vauxhall) with about 90 HP before. And it was a bit less grippier, but I still had the impression of a bit better grip than in LFS.
Now I drive a Opel Astra Coupé with about 150 hp. It has a sports suspension and is a bit more towards sports. Its still no real sports car, but there is a lot of difference in corners. I tested it often in corners I know blind, where there is a lot space and no other people, that can get in danger and I still was afraid to push it harder. It grips so well. So it took a bit of time, until I got it to the limit.
A real sports car has even a higher limit I am not really sure how much I would dare to get it to
But even my "slowish" car is very hard to get to this very last limit, which occurs in lfs quite often. The cars in LFS are mostly a bit more sports cars
It is not really comparable to a simulation at the PC, but it is much harder to get out of control in a real car in dry condition. You have to really steer brutally fast ... and even than my car is really really stable.
Just let someone drive a slow round in LFS, who drives for real ... he certainly will have an accident or at least spin in a RWD, even if he/she isn't pushing really, but just driving slow.
RWD cars aren't that bad by far in reality. I also drive a 180 hp RWD Omega from time to time. And it will understeer at the limit, wobbling around with the soft suspension
But still grips better and won't by far spin as fast as in LFS, which is for sure also a lot because of different setups and ESP Systems.
In LFS even at low speed a rwd oversteers sometimes. Its hard to reproduce, but just try the FZ50 with very soft accelerations and careful steering.
I tweaked everything in setup. Open differential, traction control on and very high, even different tyres in front and back. And still it is a dangerous car, whereas a porsche 911 happens to be driven by old people, unexperienced women etc. and won't crash, until really pushed hard.
EDIT: btw. I think that the cars with slicks grip quite realistic, eventhough I really can't compare that to RL experience. But it just feels right. But some people who have real slick experience still describe rl slick grip higher ...