What would you consider a thick oil ?

[Merkava_4]

At what point does oil become a thick oil ? 5w30 ? 10w30 ? This oughtta be good.

 

[Doog]

10w40

 

[SavagePatch]

Castrol Edge 0w30 (European Formula) seems to be a "thick" oil, at least thick for grade. I guess I would say that an oil becomes thick when it is at the top of its viscosity range and on the verge of being the next higher range.

I'm sure that opinions vary.

 

[WiskyBadger]

Originally Posted By: Doog
10w40
+1

 

[bbhero]

0w40, 5w40 or 10w40 at operating temp. Or an HTHS over 3.9. Of course there are some light 40s less than that. Which we all know which ones they are.

 

[mrsilv04]

Whatever that [censored] is that they put in Harleys.

Straight 60 weight. Yeah, that might be thick enough.

 

[Shannow]

I a passenger vehicle, 15W40 with an HTHS over 4 is about where I consider thick to start.

As to too thick, 25W50 and up with an hths around 6 is too thick to be useful IMO.

 

[CarbonSteel]

xW-40 and above.

 

[deven]

15w40 and up

 

[Noobie]

15W-40 is normal for HDEO's and Diesels (Overseas) so i wouldn't consider that thick.
Anything above that is definitely not normal or common IMO.

 

[Chris142]

Sae40 @ 25f

 

[Doug Hillary]

Hi,
Shannow - I have often provided the history of 20W-50 on here. It was especially developed in 1958-9 for the Austin-Morris Mini. It had a specific purpose - to enable permanent shear with OCIs of around 1k to 1.5K miles - and to stop leaks

The A series engines in other vehicles handled the 20W-20, 20W-30 and 10w30 very well

In the Minis the 20W-50 viscosity introduced serious technical issues during cold weather!

20W-50 quickly became the "fix-it" viscosity at a time when lubricants were quite unsophisticated compared to today

I also agree that we tend to forget the importance of the HTHS viscosity over-all when we compare "thick" and "thin" viscosities

 

[Kamele0N]

xW50...xW60...

 

[slipperysam]

anything over 30 weight when the engine is hot
and anything over 5W when the engine is cold

 

[Lyman]

I used to run Redline 20w60 in my Harley.

 

[oilboy123]

My first thought was 40 wt before I read the other comments. Everybody else confirmed I was not in la la land.

 

[Dyusik]

Thick oil is relative term to me. 15.9 cst delo is thick a 40wt and m1 0w40 is thinat 13.5. I will usually refer to thick oil as above oem spec, though I don't limit my reference to the US (thinner) specs, rather an average of collection of worldwide specs.

 

[Shannow]

Originally Posted By: slipperysam
and anything over 5W when the engine is cold


A 15W is roughly the same MRV and CCS in my coldest ambient as a 5W is at -30C...

 

[FCD]

I've run Shell Helix 3 25w60 in my Ford Capri , the engine really liked it during the summer days when it was over 40c ( 100-105 F ) , i'm using the same oil but in 20w50 form since i can get it locally
A company from australia called Penrite makes 40w70....
https://media.autobarn.com.au/media/cata.../P/HPR50005.jpg
This is really only to be used in pre-war cars with massive clearances

 

[Gasbuggy]

15w40.

Though I don't consider most 5w50 synthetics to be thick, and neither does Ford apparently.