Internal combustion engines typically have low efficiency, with modern gasoline engines around 35% and diesel engines ...

Just days ago, Porsche patented a revolutionary six-stroke engine that combines the power advantages of a two-stroke engine with the durability and lower emissions of a four-stroke engine. Traditional ...

Like countless other 19th-century inventors, entrepreneurs, and tinkerers, British engineer James Atkinson sought ways to improve on the Otto four-stroke combustion engine, first produced in 1876. The ...

From the January/February 2025 issue of Car and Driver. A patent for a six-stroke engine would normally go directly into our crackpot-engine file, but when the patent filer is Porsche, we feel ...

"Too little compression will usually result in unmet performance expectations. On the high side [too much compression] carries greater risk in tuning and potential component failure if appropriately ...

Mazda’s new SkyActiv-X engine will go against every convention you thought you understood about gasoline engines. It’s supercharged, but for efficiency purposes, not to increase power. It has a ...

starts with the piston at the top of the cylinder (TDC) and the intake valve open to admit air and fuel. At bottom-dead-center (BDC) the inlet valve is closed and the compression stroke (b) starts.

Last month we acquainted you with a few unique procedures for using conventional tune-up devices—such as a vacuum gauge, timing light and electrical analyzer—for evaluating the efficiency and ...

The piston rides up and down inside the cylinder on a connecting rod that attaches to the crankshaft, causing the crankshaft to turn. Each movement of the piston is called a stroke. Four strokes — ...