What's the lexus is250 exhaust pipe size?

The Lexus IS250 comes standard with a 2.5 inch diameter exhaust pipe. This is the size that will fit properly in the stock exhaust channel that is located under the vehicle. If You want to put a new tip on the exhaust it will need to be able to fit the 2.5 inch piping that is there. If You want to improve the power and torque from Your engine then You can use a larger diameter exhaust pipe and You can use larger headers as well. If You combine that with a new intake as well You should be able to also get greater throttle response from the vehicle when You accelerate while driving.