Diesel cycle engines are inherently more efficient because they don’t rely on stoichiometric ratios for ignition. Mechanical diesels don’t need electrical systems of any kind to function either. Because they rely on combustion chamber temperatures for fuel ignition, cold starts can be rough. Starting tip: turn off the fuel, crank the cold engine for 20 seconds, while continuing to crank, turn on the fuel. If that doesn’t work, try a quick shot of ether while cranking with fuel on. 

 That's your personal experience then🤷🏻‍♀️ 

 Dammit I sent it before I wrote more.😀 I didn't say they don't start or go right away. I'm saying they're lazier and need to be heated. Driving cold diesel on short distances ruins the engine.