BY the way Diesel fuel in Finland costs about 7-8 bucks /gallon.

Fuel additives/freeze prevention
 

I use tpx-hd

Shell V-Power diesel, with Amsoil Diesel Concentrate Additive summer & winter.

Amsoil & Stanadyne seem to give me the best "sound".

Never found the need for an anti-gel, as the winter diesel has added de-icers.

I stay away from adding cetane to an already high(ish) cetane fuel, as I was told it reduces winter lubrication.

No need to use anything as an anti gel on a regular basis. Fuel is blended for the climate in the winter.
Only time it is necessary is in an extreme cold snap, way colder than the average low temps for that area, or if changing climates substantially on the same tank of fuel, example, leave Phoenix in Jan, drive a couple hundred miles up into the mtns and they're having cold weather.
In my 15 years of diesels including 2 years in AK with winters on the north slope I've rarely used anything and never gelled up.

There was a day in Denver about 6 years ago where they got a super cold snap, like -30 one night. Almost every diesel powered anything in the city was gelled up. Stores sold out of 911 immediately. I had a dozen pieces of equipment gelled up. Drive 2 hours up in the mountains where they weren't affected and bought out all the 911 I could. Saved like 20 for myself and sold a pile of bottles to every guy I passed that day for $20 a bottle!
Made beer money for a month!