What do you mean "older ones"
I apologize for the terse attempt at humor…
YOu are in LA I see…. (great places there are favorites of mine and have good friends there I sometimes visit)
OK… Down South where the climate is humid most of the year… YOu need a biocide in your fuel if you store any other than in the fuel tank of the tractor itself. I recommend Biobor-JF...follow the directions.
It is extremely unlikely you will EVER need an anti-gel…which is only required when temps get below 15-degrees F…. so don’t mess with it.
Some folks worry about lubricity in older diesels operating on ULSD (Ultra Low Sulfur Diesel) which is all you can buy these days. Don’t sweat it and ignore all the “sky is falling” fear-mongers is my opinion…but if you succumb to the fear mongering…. pour a little 2-stroke oil into your fuel.… about HALF amount as recommended on the bottle for 50:1 ratios.
Cetane improvers…. skip ‘em.… they are snake oil…usually alcohol which will attract atmospheric water and will ruin your injectors.
In other words…. use clean No 2 diesel, either from the service stations or dyed-diesel…they’re the same thing except one doesn’t charge road taxes and has red dye in it (which you never want to use in a true highway vehicle.)
That’s it.. Use the older additives…I.E. nothing but plain, clean, diesel fuel.
And WELCOME to OTT!