Assuming the diesel pump has the correct size nozzle:
not to big -- for big trucks to fill up quickly
not too small - for unleaded gasoline....

The only real issue is that diesel is 'oily'. So it leaves a residue on the pump handle when others are a bit sloppy when filling up. The better stations clean up the pump handles fairly regularly. But some stations just let them get grungy. So it helps to wear a glove to avoid transferring the grunge onto your clothes or steering wheel.

Out here in the country we just wipe our hands off on our pants, or if you're real prissy, on your socks

Funf Dreisg