During a cold start, friction between engine components increases due to the lack of immediate lubrication. This can lead to accelerated wear on critical parts such as pistons and cylinders.

Diesel engines are pretty different to gas engines, and that extends to cold starts. Cold starts can somewhat hurt a diesel engine, but it's not that simple.

There are cold starts, and then there's this cacophony of sounds you get when trying to start a diesel truck at 30-below-zero.

C. Arcoumanis, M. Duszynski, E. Pyke, H. Preston, Cold-start Measurements of the Lubricant Film Thickness in the Cylinder of a Firing Diesel Engine, SAE Transactions, Vol. 107, SECTION 4: JOURNAL OF ...

ABSTRACT Future emission standards for Diesel engine will require a drastic reduction of engine-out NOx emissions with very low level of particulate matter (PM), HC and CO, and keeping under control ...