What is the lowest reasonable temp you would run a 10W 30 or 40 weight conventional oil ? ...I have heard for a conventional 10W any where from 0 degrees F. to 32 degrees F . but perhaps it will even pump adequately below 0 dgrees F . ? My main area of interest (based on where I live) is that +0 degrees F and above . for 10W conventional. ... Your thoughts and experiences ?