I was just informed that the 05 gs430 got a 5 speed auto trans from the factory, where as the 04-06 ls430 gets a 6 speed auto trans.

Yet they both have the same motor, just curious as to why the gs got the 5 and not the 6?

 

i believe all USDM second gen GS came in 5 speed. 98-05. the ls supposedly the flagship model so im guessing it got a six spd.

 

Lots of reasons...probably the main reason being that the GS had the same auto 5-speed since '98 and the cost of adapting the 6-speed for 2 model years was prohibitive when they considered that it wouldn't likely help them sell andy additional units.

The LS is a big, heavy car, too. It can benefit from more, shorter ratios.

 

04-06 ls was a MC from the previous MYs. the GS got its MC in 01 when they didnt have the 6 speeds yet.