I have an '03 LS430 and live in the northeast, where there's pleanty
of snow.

The traction control helps a lot, but this is still a heavy rear wheel
drive car.

With snow tires (or in my case, Nokian winter rated tires), the car
does much better, perhaps as well as a front wheel drive car.

With "Normally used" summer tires, I would expect that the car
wouldn't handle very well at all in snow or ice.

HBH

i tried my ls430 with stock (new dunlops) in the snow and quickly gave them
up.
the car would not move - i have a very small incline on my driveway and i
could not make it out of my house.

using dunlop m3 winter tires - the only way to get by in this vehicle.

I use Dunlop's Winter Sport M3 on my 2004 LS430and it is almost as good as
my LX470

Summer wise, Goodyear Eagle F1 GS-D3, suberb handling at speed including in
the rain and downpours, slightly increased road noise compared to my son's
2005 LS430 w/ standard tires.