GM engines focusing on efficiency through technology

American automobile manufacturers may be playing catch-up to their Japanese rivals in terms of engine technology, but GM is now making significant headway thanks to a number of initiatives to improve fuel efficiency and lower emissions.

Thanks to a new engine lab built in Detroit that operates 24 hours a day, GM is set to roll out a range of new innovations in their engines, including new hybrid technologies, the growing replacement of displacement by turbochargers and superchargers, weight reduction of powertrains and new technologies such as HCCI.

GM intends to launch around 16 new hybrid models over the next 4 years, including the long awaited Chevrolet Volt. The Chevrolet Volt marks a significant departure from traditional two-mode hybrid technology (such as that found in the Prius), in that only an electric motor can power the wheels while a gasoline motor recharges the lithium ion battery pack.

Replacing high-displacement vehicles with low-displacement alternatives, such as turbochargers, has also been a successful strategy with the Pontiac Solstice GXP - a car which generates 260hp from a 2.0L turbocharged engine, or 130hp/L. While the Solstice GXP uses direct injection and turbocharging to achieve this figure, GM is keen to incorporate HCCI into the equation to further improve economy and performance, reports Automotive News.

HCCI offers diesel-like efficiency for petrol engines, and can allow significant improvements in fuel economy and emissions levels by eliminating the need for a spark plug to ignite the air/fuel mixture in each cylinder.

The introduction of direct injection technology is also making inroads at GM, especially considering the improvements that can be achieved relatively cheaply, with cars showing improved mileage, performance and lower emissions, as seen with the Solstice GXP. The 3.6L direct-injected V6 engine used in the Cadillac CTS (pictured) has won acclaim for its combination of power, smoothness and efficiency.

In terms of future engines, GM is not focusing on one segment or area, instead choosing to improve their engine range across the board. Already, two new diesels are being developed, including a 4.5L diesel V8 for certain trucks and SUVs as well as a separate diesel engine for cars. For Europe, a V6 diesel engine is being designed in conjunction with an Italian company, although whether or not this engine will make it to North America is uncertain.

Meanwhile, petrol engines are being downsized and made lighter, and combined with lighter, 6-speed gearboxes fuel efficiency is expected to increase significantly.