gurus...need help with viscosity

[TooSlick]

Dragboat,

If this oil was gelled at room temp, it would seem to be some sort of additive reaction, or problem with additive stability. I have seen 1-2 cases where a previously opened quart of oil will get excessive moisture in it and you will get some gelling. This generally only happens if an ester basestock was used, such as in the case of a two stroke synthetic. If this oil was less than 5 years old and the container was unopened, it is very odd indeed.

If you get down to the pour point, then any oil will start to gel ....

TooSlick

 

[matt cook]

got this reply from Shell...would you be worried about the seals in a 10 year old, 40,000 mile engine?

"Matt -

Thanks for the opportunity to respond to your inquiry, and thanks for using Shell products.

Both ROTELLA T SAE 15W-40 and ROTELLA T Synthetic SAE 5W-40 are extended drain capable. So using the same drain interval is no problem. Compatibility is not a problem either.

With engines operated for a long time on mineral based oils, sometimes switching to a synthetic can result in oil weeping or seeping past engine
seals. Some elastomer seal materials change their swell characteristics when exposed to synthetic base stocks. You may want to look for this when switching."

Peter Van Benthuysen

Tel: +01 281 544 8253
Email: [email protected]
Internet: http://www.shell.com

 

[MolaKule]

Dragboat,

I have only seen this happen with petroleum 2-cycle oils in which the solvent had evaporated. I have never seen this happen with modern oils, dino or synthetic.

Matt,

Seal compatibility is no longer an issue with synthetics that contain esters.

 

[matt cook]

I know that the Rotella Synthetic is a Group III, but does it contain esters?...

CAS# CONCENTRATION INGREDIENTS
Mixture 100 %volume Synthetic Motor Oil
92062-09-4 65 - 74.99 %volume Hydrotreated Petroleum Slack Wax
64742-54-7 10 - 19.99 %volume Hydrotreated heavy paraffinic
distillate
Mixture 3 - 8.99 %volume Hydrocraked, hydroisomerized HVI
paraffinic oil
Proprietary 3 - 8.99 %volume Proprietary additives
64742-65-0 1 - 2.99 %volume Solvent dewaxed heavy paraffinic
distillate

 

[MolaKule]

"Mixture 3 - 8.99 %volume Hydrocraked, hydroisomerized HVI paraffinic oil."

Interesting, only 3-9% Group III oil, and they are calling it synthetic.

No esters.