If you’ve been looking at buying or leasing a new car,
we’re sure you’ve discovered that a lot of things have changed “under the hood”.
At Natural Resources Canada, we think that a little knowledge can go a long way toward helping you
find a vehicle that will deliver good gas mileage and reduce greenhouse gases,
effectively harnessing these new technologies for your – and the planet’s – benefit.
Let’s talk about changes in engine technologies, and how they’re helping make vehicles more efficient.
Shaken, not stirred: Direct injection
Direct fuel injection systems can optimize fuel delivery by injecting fuel directly into the cylinder at a high pressure,
in contrast to conventional systems that inject fuel into the intake air stream at a lower pressure.
Direct injection systems allow for better control of the fuel-air mixture, and can reduce fuel consumption by 1 to 3%.
I’ll Take Two: Cylinder on Demand
No engine needs maximum power output all the time.
Cylinder deactivation systems or CDS are typically used in 8 or 6-cylinder engines.
These systems shut down half of the engine’s cylinders when only a small percentage of the engine’s available power is needed,
such as when driving at a constant speed on a level road, decelerating, or going downhill.
Cylinder deactivation systems can reduce fuel consumption by 4 to 10%.
For the driver, the vehicle’s computer manages everything -
giving you the power you need when you need it, and reducing it when you don’t.
Take a Deeeeep Breath: Turbocharging
Engines can achieve more power if more air and fuel can be forced into the cylinders for each combustion cycle.
Turbochargers use exhaust gases to drive a turbine to compress air into the intake manifold,
which is then forced into the cylinder of the engine.
This provides two benefits.
First, there is more air and fuel providing a larger combustion reaction and more power.
Second, less work is required from the piston to pull the air/fuel mixture into the combustion chamber.
Turbochargers are able to force air into the engine’s cylinders,
in contrast to a naturally aspirated engine that draws air in at atmospheric pressure.
This enables a smaller displacement turbocharged engine to produce the same power as
a larger displacement naturally aspirated engine.
The use of a downsized turbocharged engine can reduce fuel consumption by 2 to 6% for equal vehicle performance.
Variable valve timing:
Just like humans, the engine in your car needs to breathe.
Engine valves control the intake of fresh air/fuel mixture and the exhaust of combustion gases.
And, just like humans, an engine’s breathing rate is based on exertion;
Conventional valve control systems provide a single fixed timing,
which means engine breathing is not adjusted or optimized for different requirements.
Variable valve timing adjusts the engine’s timing and breathing based on the operating conditions of the engine.
VVT can reduce fuel consumption by about 1 to 6%.
Okay – that’s it for now.
Lightweight, powerful, and as smart as can be, today’s new engines are miracles of emerging technology,
and they are significantly more reliable and long-lasting than in the past, with lower service intervals.
Shop carefully, and choose the combination of engine features that best suit your driving style.