Thanks mate and yeh i beleve its a 6 cyl auto buddy if that means anything to u...
If its a 6cyl its the IS200 engine, So you have 160BHP or there abouts the Altezza engine is a 4cyl and around 200BHP. The redline on the tezz is 8000RPM ish and as far as I know its around 6500RPM on the 6cyl. .
Your car is a jap version of the is200 by the sounds of it. .Any pics of the car and engine and we will be 100% sure and help you out