After doing quite a bit of hard driving, it is my belief that the VDIM does not beep or flash a light on the dash when it intervenes. The traction control will flash if the rear wheels begin to spin and if you really begin to slide sideways the VSC will beep and light will flash.

Is this a correct assessment? Is the VDIM supposed to be silent when it intervenes?

 

but is pretty silent most of the time so you might not know how many times it has done its job. You need pretty slick conditions to get it to beep. As you know by now it is my favorite feature and really needs to be on every Lexus modelfrom now on. That would require the new models to have Electronic Power Steering like the GS430 which also has the VGRS. (Variable Gear Ratio Steering) Did you see the Canadian review of the VDIM? At fifty miles an hour on wet tarmac they made a U turn and the GS430 made the tightest arc with VDIM. The AWD came in second and the RWD GS300 had the largest arc. This confirmed my experience and echoes your write up which was excellent. VDIM rules........

 

I did read the review and thought it was very impressive the tarmac tests they did. Can you explain the Electronic Steering a little better. I think I know what the Variable Gear Ratio is, but is the Electronic Steering actually electric? Or is it rack and pinion steering with electronic assists. Is there still steering linkages between the steering wheel and the wheels?

 

and this gives the assist or resist as the case may be. About half way down the steering shaft from the steering wheel there is variable steering gear unit that can vary how much movement of the steering wheel will move the steering rack. The VDIM can steer the car slightly on its own when it decides that is the best correction such as slippery pavement on one side of the car and good traction on the other. In the pictures of the article you could see them testing that feature. I would like to shake the hand of the engineer who designed this system as he is a hero who will save many lives. It allows Lexus to give the suspension some compliance without sacrificing agility. As SPWolf reported it did just as well in the slalom tests as the "Sportier" M45 with the 19" wheels so further testing is welcomed. Since most people don't know what it is yet or how it works they react with more than a little skepticism. You risked your new GS430 in good faith and I'm sure you are more confident in slippery conditions now. It also helps during panic braking while engaged in a curve like an exit ramp. The GS430 will not jack on you and has a calm feeling during emergency maneuvers. BTW, what is your impression of the Hughes Braking System? It's money!

 

I plan on doing more hard driving and testing the system out. I will tell you that I was driving through a curved on ramp at about 50MPH and decided to push full throttle. Ordinarily, the back end would have tailed causing me to oversteer. But the GS adjusted the steering to counter that effect and the throttle was adjusted but only slightly. I still managed with plenty of expected power out of that ramp.