Cylinder Deactivation Technology.

Car makers are continually developing new technologies to minimise fuel consumption and, in addition to clever turbocharging, direct injection and advanced valve timing, cylinder deactivation is another economy boosting trick.

In India, Volkswagen & Skoda adapted the technology for use on its 1.5 TSI EVO Petrol Engines,

VW TROC, Skoda Koraq & Upcoming Taigun GT, Kushaq has this technology. 

Volkswagen calls it Active Cylinder Technology(ACT).

Volkswagen is the first carmaker to implement this fuel saving cylinder deactivation technology on four cylinder engines, as it was previously the preserve of large eight or 12 cylinder engines.  

Audi’s calls it Cylinder on Demand. RSQ8,Rs7 have Cylinder on Demand Tech in India.

Cylinder Deactivation technology is technically called as variable Displacement technology. 

Variable Displacement is an automotive engine technology that allows the engine displacement to change, usually by deactivating cylinders, for improved fuel economy. The technology is primarily used in large, multi-cylinder engines. Many automobile manufacturers have adopted this technology as of 2015, although the concept has existed for some time prior to thi.

So How does cylinder deactivation work?

Illustration by PETE SUCHESKI

Valves at the top of the cylinder open and shut in a specific pattern to precisely allow fuel and exhaust gasses in and out of the cylinder. When an engine fitted with cylinder deactivation detects the car is cruising, a solenoid valve opens and a system forces the valves shut, preventing fuel and air from reaching some of the cylinders.

This means combustion is only taking place in half of the engine and thus much less fuel is burned when cruising.

To make sure the system engages and disengages unnoticeably, and doesn’t cause damage to the engine, it’s very precisely controlled by the car’s computer. The system detects if you’re at a roundabout or anywhere where you might need a burst of power and deactivates, only coming in once it’s sure you don’t need the extra power. In fact, the only way most owners will know if it’s on or not is by a readout in the instrument cluster.

It’s a smart process that not so much increases fuel efficiency, rather it decreases fuel inefficiency.
Cylinder deactivation is just one of a number of ways car makers are reducing the impact on the environment and your pocket.