According to the manufacturer, each 627 combustion chamber is precision- machined to create a unique combustion event that increases horsepower and delivers more than 600 foot-pounds of torque from 3,000 rpm through the power curve. Horsepower is increased through the rpm range, boosting acceleration and improving top speed potential. Seven has also developed a proprietary ECM calibration to optimize top speed and midrange fuel economy. The rated speed of the 627 is 5,500 rpm, 100 rpm higher than the 557, which will assist in propeller selection. Fuel requirements for the 627 remain at a minimum of 89 octane plus 10 percent ethanol.