The SC400 is a 4.0L V8, but the SC300 gots an I6. Basically supra.

SC300 definently

The SC400 is 100 faster.

SC3000

Stock to stock, the 400 is faster. BUT the 400 also only comes in auto. What people seem to forget is that the SC is r not all out sports cars, they r sporty-luxury cars, the V8 is silky smooth & provides linear power, MORE power than the i6 in the 300. It is a heavier version of a supra, which is heavy to begin with.

Whoever says the 300 is faster is complety ignorant unless they explain themselves, from the factory it is not, it was the cheaper version for a reason BUT Let me explain to u why the i6 in the 300 has more potential IF u were a tuner. The I6 is from an Non-turbo supra, & the internals can take a beating, so if u were to turbo the motor, the 2jz in the 300 has been proven to be able to take boost very very well, with supporting mods & when done right can yield 400-500whp with proper supporting mods.

So short answer is no, from the factory it is not faster & if u r looking for a car to get into & just drive, the 400 is will be quicker, smoother & very reliable. BUT if u r a tuner & like to fiddle with things, by all means get an sc300, there is a lot of potential.

RT could not have said it any better.

what he said about stock to stock is VERY true. The 400 is faster but like he said only in auto.
If u r looking into forced induction, performance accessories, & avalible parts for one of them the SC300 is a MUCH better choice. l have a 300 & a 400 & my 400 is modded out (unless u spend 5-6k on a supercharger to gain 100hp) but u can spend the 5-6k & have a good 450-500hp car. My SC4 has intake, exhaust (3 inch), & its got a GREAT tune with a chip. It made 310hp on the dyno.and thats a LOT for a SC4. Just look up the 2jzge & 2jzgte. The ONLY difference internally is the GTE has oil squirters & ive NEVER heard anyone make a complaint about not having them. (yes l know the GTE is TT just for the other 2jz-aholics)

The SC400.

The faster version of the Toyota Supra was twin turbocharged.
The SC300 is not turbocharged, so it is much slower than the Toyota Supra, and heavier.