I worked for Lubrication Engineers (LE) in Fort Worth, Texas for 2 years. They make excellent synthetic lubricants. I have used LE products in some of the most abusive environments such as paper mills, asphalt plants & equipment, feed mills, meat packing plants, open pit mining drag lines, ready mix concrete operations, waste water treatment plants, etc. and they are second to none.
I am not saying they are the best, just saying LE makes very high quality lubricants that will get the job done.