This is a rather generalized statement. Not all twins make less power. Look at the TL/SV1000. It's making up close to inline 4 liter engine power (the orginal TL truly did match the liter bikes of it's day). The only difference is that the twins make their peak torque at a lower RPM range so they feel a lot more grunty when the RPMs are lower.vtwins have less horsepower but more torque and I-4 is vice versa. Vtwins also gas guzzlers.