At first glance, the concept of engine compression is simple enough:It's the ratio of the volume of the combustion chamber and bore when thepiston is at bottom dead center (BDC) versus when it is at ...

You've heard the term compression ratio before, but have you ever wondered exactly what it means? Well, it's time to explain exactly what compression ratio is, and why every carmaker is now obsessed ...

Strictly defined, compression ratio is the total volume above the piston at bottom dead center (BDC), divided by the total volume above the piston at top dead center (TDC). First, let's look at the ...

In a conventional piston engine, the compression ratio defines the relationship between the largest and smallest volume of a cylinder - when its piston is at bottom dead centre and top dead centre ...

Forget variable length intakes and variable valve timing, Infiniti is going all the way and introducing variable cylinder compression ratios. The new VC-T turbo engine automatically adjusts between a ...

A gasoline piston engine that can dynamically change its compression ratio —that is, the amount by which the piston squeezes the fuel-air mixture in the cylinder—has long been a holy grail of engine ...

Ever since the first internal combustion engine hit top dead centre, engineers have been locked in an inexorable battle with compression ratios. Too low a compression ratio and the engine's efficiency ...

If you know much about how engines work, the idea of a variable compression ratio seems almost crazy. The idea isn't new, in fact Saab claims to have been working on it since the 1980s, but it's never ...

Apart from the very curious, not many people ask why diesel engines, compared to gasoline, run higher compression ratios. The argument is reasonably straightforward and starts with fuel ...