GrandSedanFan

iTrader: (1)

That's great information, thank you.

Do you know if the additional height of the AWD vs. RWD is based on hardware or spring length? I know the front struts are completely different to clear the front half shafts. I don't want to hammer my shocks with lowering springs, but I would not be upset with RWD ride height. I don't understand why Lexus insists on making their AWD sedans (except for the early 3IS) sit like scared cats.

peteharvey

I don't know exactly why, but I would imagine that if the AWD is taller than the RWD, then that is most likely due to coil spring length and even spring rates in lbs/ins.

jgscott

iTrader: (1)

Is it weight? I would guess the AWD weights more with the front diff too? But then again the weight would be down on the frame and drivetrain not the body.

peteharvey

True. The extra weight of the AWD transfer case and front axle would result in firmer spring rates at the front, and to a lesser extent at the rear.

Lexus may deliberately give the AWD more ground clearance and spring travel to cope with non-bitumen surfaces.

GrandSedanFan

iTrader: (1)

Nevermind; I think it's in the strut. I did the non-scientific study of looking at AWDs and RWDs with the same set of aftermarket springs and, with same length and rate springs, the AWDs still sit higher in the front.

The AWD does weigh more and that weight is up front. The RWD GS weighs 3726lbs with a 53/47 FR weight distribution, the AWD is 3891lbs and 54/46 F/R. Rough math works out to an additional 200lbs over the front of the car.

Based on a spring rate document that I saw in a different thread, all 4GSs are set up with front springs that are stiffer than the rears, which is readily apparent in my car's steady state understeer. Reducing front spring rate would go a long way towards neutral handling.