The credit crunch and spiraling cost of fuel caused train company First Transpennine Express to explore how they could cut costs.

Their engineers calculated that they could save 7 percent of the fuel costs by bringing in the measure which they say passengers shouldn't notice.

Computers will use GPS to calculate where each train needs to use all three of its engines and when they can be turned off without effecting performance.

Other plans that could be brought in if it gets too bad include turning the engines off altogether and telling passengers to walk.