Nissan Motor Co. said Friday it has developed jointly with Stanford University and Physical Science Inc. the world's first technology to measure in-cylinder gas temperatures and a way to analyze the combustion in "real time" during engine operation.

The new technology is expected to contribute toward developing future-generation engines with improved fuel efficiency and reduced emissions, the automaker said.

The technology uses a semiconductor laser to calculate the temperature from measurements of the gas concentration in the combustion chamber.

With the development of a very small temperature probe that can be installed in a spark plug, the technology can now be applied to any type of auto engine, enabling nonintrusive, real-time measurements, the company said.

Previous methods to measure gas combustion required modifications to the engine.

Acquiring useful data by attaching sensors in cylinder walls or estimating temperatures from camera images had proven difficult.