Lithium, you are right in some ways, I know the gtst is 100 k lighter, and if you have an RB30 in it, has to be iqually matched with a strong gearbox, so u'd have to dish out the standard gearbox on the gtst, and go for some heavy duty box and that means its going to be heavier, Supra comes with a standard Getrag gearbox, what a freebie hey. Mind you my R33 GTR was heavier than my supra, the auto supra is 1500 kilos, the manual soops is 1400 kilos. And obviously the GTR is going to be quicker 0-100, but after that its all about the Soops.