Which is also the case for Yamaha's new 1.9-liter four-cylinder, which makes 200 hp at 7600 rpm and can be found powering high-output WaveRunners and jet-drive boats.

AVL had a pretty good day earlier this month, when it confirmed its prototype 2.0-liter turbo hydrogen race engine could generate over 200 hp-per-liter. AVL uses a water-injection system alongside ...

The video above compares air-cooled engines to water-cooled. ... 911 Turbo produced 450 HP in its top iteration while the current 911 Turbo S version cranks out 540 HP, partly thanks to water cooling.