Curious what the thoughts are on these three. This is for my 1996 Land Cruiser which specs a Dexron III fluid. I have been running D4 for the past 20 years in it without issue. Mobil 1 is $10 a quart, D4 and HPL about $15. Do I keep running what has been working, save a bit of money and use the Mobil 1, or given the lack of price difference, switch to HPL?