I just put ATF in the tank year round as a fuel lubricant, and Power Service during winter. White bottle for above zero, and red bottle for below zero. It is super expensive, but, the company I work for uses it, have gelled up equipment that wasn't winterized, but, only ever gelled up one thing that was, and had been sitting for awhile, and, we were trying to start it in -48*... and it was kinda gelled up. Got it to run off of Power Service Diesel 911, the red bottle, and then after more cranking and ether spraying, it fired up and knocked like hell. So I am a believer in that stuff. It's overkill.