Nissan variable-compression gas engine: Is diesel obsolete?

Nissan revolution: could new petrol engine make diesel obsolete? - Business Insider

ATSUGI, Japan (Reuters) - Japanese automaker Nissan Motor Co has come up with a new type of gasoline engine it says may make some of today's advanced diesel engines obsolete.

The new engine uses variable compression technology, which Nissan engineers say allows it at any given moment to choose an optimal compression ratio for combustion - a key factor in the trade-off between power and efficiency in all gasoline-fuelled engines.

The technology gives the new engine the performance of turbo-charged gasoline engines while matching the power and fuel economy of today's diesel and hybrid powertrains - a level of performance and efficiency the conventional gasoline engine has so far struggled to achieve.

The turbo-charged, 2-liter, four-cylinder VC-T engine averages 27 percent better fuel economy than the 3.5-liter V6 engine it replaces, with comparable power and torque. Nissan says the new engine matches the diesel engine in torque – the amount of thrust that helps determine the car's acceleration.

The engine is also cheaper than today's advanced turbo-charged diesel engines, Nissan engineers said at the briefing at the company's technical and design center in Atsugi, south of Tokyo. They said it should also meet nitrogen oxide (NOx) and other emissions rules in certain markets without requiring costly treatment systems.