I have a Belle MiniMix 150 110V Electric Cement Mixer the documentation says to use a EP90 oil in the gear box, but these days it seems that most outlets only sells EP80/90 oil.
What is the difference and does it matter?
(I am asking on a mechanics.stackexchange as I need advice for people that understand gear boxes and oils.)
80W90 is a multiviscosity version of the single-viscosity 90 gear oil; it's the same concept as 10W30 motor oil being the multiviscosity version of single-viscosity 30-weight motor oil. The "W" is a "winter" rating, meaning that the oil in question is designed to be usable in winter months in cold climates.
80W90 oil is perfectly satisfactory for your purposes in a cement mixer - it can be either GL4 (with very little molybdenum disulfide) or GL5 (with lots of moly-d)... for a cement mixer I'd recommend using the GL5 because you have no brass synchro components for the moly-d to attack. GL4 is for older manual transmissions that can't tolerate moly-d because they contain brass. For gearboxes that can use it, moly-d adds extra protection against wear, especially in cases where regular maintenance is unlikely.
much like motor vehicles (depending on age) some makers recommend mineral based oils some synthetic.They do this for a reason as viscosity/additives vary.Use what they specify.Lubricant makers have websites,some of whom allow you to pose questions regarding lubricants and applications
