OIL:)

[mo-racing]

in my lucky position at work i sometimes get the chance to speak to engineers of different companys. after a conversion with a guy from shell i had this opinion on oils.

this is what an application engineer told me:

for lubrication synthetic is many times bether than mineral.
for durability synthetic is not good. the synthetic stuff is "breaking" at higher temperatures in a periodically way (above 100-110°C this happens quickly!).
the first number is the viscosity of the base oil. the second number is the viscosity reached through chemistry.
oil with a big viscosity range has lots of synthetic and breaks quicker.

what is semi-synthetic???
these are synthetic oils as well. every oil that has a viscosity range has synthetics. they just say full-synthetic to 0W-xx and 5W-xx oils. everything else is called semi-synthetic



so i will use 10W-40 for everyday and change it after 5 - 10tkm. and for trackdays i will get 20W-50 valvoline because of it´s thicker base-oil and less synthetic stuff. (also heard from drag racers who stoped breaking bearings after changing from 10W-60 to 20W-50)

for gearbox oil i will choose a safe 80W-90 and for diff i will try the 75W-140 diff oil from castrol.