Cylinder deactivation systems

Vehicle manufacturers are adding cylinder deactivation systems (CDS) to some light-duty vehicles to help them meet Canada’s increasingly stringent greenhouse gas emission standards.

A CDS can lower fuel consumption by 4 to 10%, saving you money and reducing your impact on the environment.

A CDS fine-tunes an engine’s power

A CDS in a 6- or 8-cylinder engine shuts down half of the cylinders when only a small amount of the engine’s power is needed. This happens in situations such as highway or downhill driving.

The “brain” of the engine is the electronic control unit (ECU). In a vehicle that has CDS, the ECU shuts down cylinders at the right moments by deactivating the intake and exhaust valves and the fuel injectors.

The energy cost to keep the deactivated pistons moving and oil circulating is outweighed by the fuel savings.

When more power is needed, such as in uphill driving or acceleration, the ECU reactivates the valves and fuel injectors of the deactivated cylinders. This returns the engine to full power.

How much a CDS can save

Over 10 years, a CDS can save you $480 to $2,800 in fuel costs and lower your carbon dioxide (CO2) emissions by 1,100 to 6,440 kg. At the high end, this is equivalent to

  • nearly 1.5 Olympic-sized swimming pools of CO2
  • removing a large SUV from Canadian roads for one year
  • about 30% of our annual per capita emissions in Canada, which is 22.1 tonnes
This table shows what a cylinder deactivation system can save you over time.
Fuel consumption 10-year savings*
Average (L/100 km) With a 4% reduction
(L/100 km)
With a 10% reduction
(L/100 km)
Fuel cost savings CO2 reduction
14.0 13.44 12.6 $1,120 to $2,800 2,580 to 6,440 kg
12.0 11.52 10.8 $960 to $2,400 2,210 to 5,520 kg
10.0 9.6 9.0 $800 to $2,000 1,840 to 4,600 kg
8.0 7.68 7.2 $640 to $1,600 1,470 to 3,680 kg
6.0 5.76 5.4 $480 to $1,200 1,100 to 2,760 kg

*Based on an annual driving distance of 20,000 km, a fuel price of $1.00/L and a CO2 emissions factor of 2.3 kg/L of gasoline.

Be a knowledgeable buyer

Research before you buy. Estimate how much fuel your vehicle will consume over its lifetime.