Syn vs dino when cold.

[ac_tc]

This is the thought:
Ive got acces to a stash of HDEO 15w40 syn but is worried
about how it compares to lets say 10w30 or 5w40 conventional when starting in lets say-20 celsius. The syn seems to have a slower "growth" in viscosity when cold than the dino and has a lower "float" value. If this holds true that would mean that i could use a "thicker" syn but still have the thinner oil´s conventional cold start properties.
TRUE?

 

[Pablo]

Originally Posted By: ac_tc
This is the thought:
Ive got acces to a stash of HDEO 15w40 syn but is worried
about how it compares to lets say 10w30 or 5w40 conventional when starting in lets say-20 celsius. The syn seems to have a slower "growth" in viscosity when cold than the dino and has a lower "float" value. If this holds true that would mean that i could use a "thicker" syn but still have the thinner oil´s conventional cold start properties.
TRUE?


I know English is not your primary language, but I don't think I could have come up with a more complex way to ask a simple question! (And yes your Swedish is way better than mine)

To answer your question, yes you can use a synthetic oil with a numerically higher XW value than a conventional oil. I have used synthetic 15w40 in winter and no way would I use a 15w40 conventional.

A easier way to look at this and ask questions is to speak in cold temperature viscosities.

 

[oilyriser]

Look for the specification called "borderline pumping temperature".

 

[ac_tc]

Jag får väl tacka så mycket..
Thank you very much, exactly the answer i wanted.
The main reason for getting a stash of HDEO is that i use it in my farm eguipment (and almost anything else ) and ive seen
how a 5w-40 syn can shear down due to fuel dilution (missing cylinder-bad plug) despite the fact that oil was used in a 100 mile tow wich boiled the gas out it remained thin (engine fixed before the trip). Ive dont trust the "low"w oils anymore.