Originally Posted by XeroK00L

Actually, the 430 has an official 0-60mph time of 5.7s.

Now regarding the 0-60mph time for the GS350, here's my calculation:

FACTS
1. The IS250's curb weight = 3,435lbs.
2. The IS350's curb weight = 3,527lbs.
3. The GS300's curb weight = 3,536 lbs.
4. The IS350 has an official 0-60mph time of 5.3s.

ASSUMPTIONS
1. The weight difference between the IS350 and the IS250 is solely due to the difference in engine displacements (i.e. port injectors and VDIM-related mechanism weigh nothing).
2. The GS350 will have the same horsepower output as the IS350 (even though according to lexus.jp the GS350 produces 3ps less than the IS350).
3. Torque remains FLAT throughout the accelerations (obviously this isn't true, but the GR engines have a torque curve broad and flat enough to make this assumption OK for a rough estimate). This also means no gear change is taken into account.

CALCULATIONS
1. Each liter of displacement in the GR-series engine weighs (IS350's weight - IS250's weight) / (IS350's displacement - IS250's displacement) = (3,527lbs. - 3,435lbs.) / (3.5L - 2.5L) = 92lbs./L
2. From 1., GS350's weight = GS300's weight + 0.5L's worth of weight of the GR-series engines = 3,536lbs. + 0.5L x 92lbs./L = 3,582lbs.
3. Since weight is inversely proportional to acceleration (F = ma), and acceleration is inversely proportional to acceleration time given the same target velocity (v = at), weight is proportional to acceleration time; therefore, the 0-60mph accerlation time for the GS350 = IS350's accleration time x (GS350's weight / IS350's weight) = 5.3s x (3,582lbs. / 3,527lbs.) =~ 5.38s =~ 5.4s

This actually makes sense since the GS350 will be barely heavier than the IS350 (heck the GS300 is only 9lbs. heavier than the IS350) and the GS430 doesn't have a torque curve nearly as flat as the 3.5L's, so in terms of 0-60 time the GS350 can win GS430 easily with more horsepower.

Remember you heard it here first.

Originally Posted by Faraaz23

Does anyone know for a fact that gearing is the same on the GS350 and IS350... that could make a marked difference in the 0-60 and 1/4 times...

Originally Posted by 1SICKLEX

Dude that was freaking beautiful. I mean beautiful.

Is the gearing the same in both cars though?

Originally Posted by jrock65

0-60 for the GS350...

Depends on who you ask.

C&D will say 5.4s
MT and R&T will say 5.9s
Edmunds and CR will say 6.3s

Originally Posted by rominl

yup, that's why i said i would be surprised if the gs460 enters the sub 5 category

Originally Posted by XeroK00L

Haha thanks, I should've looked it up before I even made the calculation post. It's all there in lexus.jp's spec page for the GS350. So the answer is yes, the gear ratios are indeed identical to those of the IS350.
http://lexus.jp/models/gs/spec/spec.html (see lower right of the table)

Originally Posted by LexArazzo

Yes, I think mid 5 is realistic, I really don't see why the GS350 cannot be within 0.2 or 0.3 sec. of the IS350 for 0-60 if gear ratios & hp are the same if the weight difference is only 88 lb. . . . . . put 1Sick in an IS350 & Henry in a GS350 & the race will be dead even

Originally Posted by LexArazzo

Yes, I think mid 5 is realistic, I really don't see why the GS350 cannot be within 0.2 or 0.3 sec. of the IS350 for 0-60 if gear ratios & hp are the same if the weight difference is only 88 lb. . . . . . put 1Sick in an IS350 & Henry in a GS350 & the race will be dead even