mjanocko

I am adding an SRT intake w/ ECU changing to a Dragon TC on my '00 GS400. I also want to upgrade from my stock 17" wheels to something wider and bigger, at what point to you start loosing performance that is counter productive to your mods?

LexFather

Considering Lexus did research on wheels for its L-tuned parts, and went with the identical size of the old E55/M5, 245/40/18 front and 265 or 275/35/18 rear maybe the best for performance. Now if you up your mods, say TC, intake etc, then it would offset 19 and 20" wheels.

Most people simply don't race their cars enough to stick to a lower size wheel. Bigger does look better on the GS (up to 20s).

rominl

iTrader: (4)

imho, if you want pure performance and handling, 18s with 245 in the front and 275/285 in the back is probably the best. 19s and 20s they will probably get a bit degrade on the performance

mmarshall

Depends on what you mean by "Performance". All else equal (which it rarely is), a larger, wider tire (especially with a lower-profile ratio) will give you quicker steering response, less understeer, better traction on DRY pavement, better braking performance, and more tire (not necessarily vehicle) load capacity. Some people (though I'm not one of them) think that the larger, the better, looks-wise.
On the negative side, a larger, wider, lower-profile wheel and tire also means a stiffer ride, less clearance in the wheelwells necessitating even firmer suspension damping, wider turning radius, slower acceleration due to more rolling friction and drag, less pothole impact protection for the alloy wheels, and lousy traction and a greater tendency to hydroplane on wet or slick roads. They can also cause low speedometer and odometer readings.
High-performance all-season tires have helped combine the best of both worlds, to an extent, but they are still a compromise.

mjanocko

Does anyone have side and rear pictures of a GS with 18" wheels based on the recommendations of 245/40/18 front and 265 or 275/35/18 rear? With peformance I am refering to laterial acceleration; I do not want to spend the money on the engine mods go with 19" wheels and have a slower than stock vehicle.

redgs4

18" Volk LE37K, 8.5/9.5, currently running GY GSD3's in 245/40, 275/35.

DaveGS4

iTrader: (2)

My GS when I had 18" JDM Piaa Rozza wheels on it 18x8 front (high disk), 18x9 rear (low disk), I'll have to go and dig to find the tire sizes but I think they're the same as those listed. I'm going to be putting these wheels up for sale soon in the CL classifieds.

mjanocko

Thanks for all the recommendations and pics!

D2-AUTOSPORT

Red, dont even ask me what rock I have been under to miss them, but this is the first time I have seen the new kit installed, it looks very nice and clean!

Back on topic, if you choose a 19/20" lightweight or forged wheel, combined with a 3.76 LSD, I think the performance will be close to, if not slightly better than stock. The biggest lag in performance due to larger tires/wheels is the taller gearing (thus softer acceleration, and a theoretically higher top speed)

redgs4

Thank you for the kind words.
The kit -is- rather subtle.

Neo

iTrader: (3)

Here is a pic of the L-Tuned wheels in question:



The tire/wheel specs for these were

Front: 18x8 235/40
Rear: 18x9.5 265/35

Interestingly enough, when these wheels went to the GS430 Sport in Europe, the tire spec changed to 245/40 and 275/35.