Quote:
On 2006-05-25 14:14, mecscc wrote:
Panda:
I don't know where the evidence is that a dino oil is only good for 2000 miles.
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Unfortunately the website where I got most of the info is either offline temporary or completely (
www.mecanducati.com).
It was based around whether or not car oils are suitable for bikes... yes that old thread
However he had the various oils analised and tested various samples at different times. Basically multigrade oils are the low number 20 in a 20/50 multigrade with 'thickeners' to make them out to the higher number when fresh ie the 50 part. seems the thickening agent does not last so very long in dino oils. so that it gets thinner quite quickly. 20/50 spectro and BMW dino oil are both down to 20/35 by 2000 miles in a aircooled bike with gearbox sharing the oil, nearer 4k miles for aircooled without gearbox and 6k miles for water cooled car engine.
I am happy to run my airhead to 3k miles on sg dino 20/50 from the supermarket and both the cars to 6k miles on 15/40 dino. Note the ratings sg, sf sh etc are unlike just about all other grading system refer to the 'maximum' performance level.. Ie an sg oil has to have less than the necessary ingredients in order to conform to sg rating. This is to protect the catalytic converters on modern machines. How ever, 20/50 or thicker oils are excempted from this maximum as they are meant for older engines without catalytic converters. It turns out that BMW oil ( sg rated dino) is runnimg with near 3 times the maximum of metal based antiwear ingredients. If it become impossible for me to find straight sg rated 20/50 car oil, I may well end up buying the BMW braned stuff
Be aware any oil that conforms to many ratings ie sf sg sh sl sj 'only' nearly complies to the one with the least anti wear ingredients. SG is the highest after that it all went down hill as far as bikes and anti wear metal compounds are concerned.
[ This message was edited by: panda on 2006-05-30 14:02 ]
