Currently been using the John Deere 15-40 in it. Its a 1993 Ford F-350 w/460. I basicly only use it to haul hay during the summer months and only sees one oil change per year and gets driven maybe 2,000 mi per yr. I need to use the truck and few times this winter and we see temps near zero here in eastern washingon. I was thinking of switching to the Rotella T-6 synthetic year round instead of the Deere oil for better winter starting. Is this a good 460 oil? thanks