A fellow TBNer posted this a short time back, (my apologies for forgetting who) and I think this is a good time to repost it. Snake oil sometimes comes in quart bottles.
The Petroleum Quality Institute of America
Exactly. Great site to go, as well api.org
For UTF/THF - a good way to tell if it's the newest add pack or not, see if it meets the -43 degree cold pour point. If it doesn't, then it's not current spec tractor hydraulic. Not saying it will harm your tractor, but it's not the correct spec for new smaller tractors.
Spec's for oils change
all the time. Major oil companies keep up with them, most high quality compound blenders do as well. Because they are the ones making JD / Kubota / MF / NH / etc. Oils. I still run into people that do not realize that diesel engine oil spec changed in 2003, from CI4+ to CJ4 oil. 4 years ago we went from GF4 passenger car motor oil, to GF5 motor oil. Now, in the next two years or less, we will be seeing GF6 and a whole new range of engine oil viscosity. Gone are the days of 10w30 - unless you count diesel engines. Ford new's spec is 10w30 diesel engine oil. We're seeing a rising demand for fleets that run new semi engines - 10w30 vs 15w40.
Oil changes, it's not just dino oil anymore. I've grown up in the oil industry, I live it, I work in it and I'm well on my way to being a certified lubricant engineer. I've spent a lot of time in different lubricant engineering schools. And for those who say "well it worked in X application" - I'll just pose this in return. The fundamentals of lubrication are simple. Even if you're not using the proper lubricant, it still might work - the question is for how long, how well, and how often do you have to change it. A perfect example is engine oil. I'm sure I could put straight 40w in my tractor and it would work fine. But I would have to change it more often, deal with dead batteries or have a block heater, and I will be putting more stress on cold start ups / the oil pump. It will work, but it's not working properly. Dull mower blades still technically work, they just don't work properly.
I still have this exact article hanging in my office... found it online. It's specifically about Tractor Hydraulic fluids.
Please read:
http://www.jobbersworld.com/Reprintmarch 3 col.pdf
Again, just because you see a label full of spec's on it, doesn't mean it #1 meets them, or #2 the spec's have anything to do with YOUR tractor. JD-303 spec is the classic example... Because, you know... Sperm whale oil is still in use... :duh:
Jobber's world is an oil industry / distributor monthly magazine. Lots of good articles in there regarding oil.