#3 Diesel was best for fuel economy
#2 Diesel is the current version of “regular diesel “ and usually delivers the most power.
Winter Blend, sometimes also called Winter diesel is usually #2 mixed with anti gel and can still gel in very cold temperatures. In the old days it was just a blend of kerosene and #2
#1 Is harder on the injection pump and lower fuel economy but a true winter fuel, it is more like kerosene
Premium diesel means something different at every station , historically it had higher than normal Cetane and would list it numerically, other stations call #1 Premium which doesn’t make sense, still others use #2 with additives to lubricate your injection pump.
In this area #1/#2 Kerosene are also at pumps and occasionally off road and #1/2 fuel oil
Too bad diesel monikers aren’t more standardized