oil inquiry

[808gt]

I usually use 10W/30 Royal Purple with one quart of Lucas full synthetic oil stabilizer on my turbo'd GT. My local shop ran out of the 10W/30 and all they have is SAE30 and 10W/40. Which one would be better to run in my car since they won't bring in the 10W/30 until later? I just need to change my oil before i can race it this weekend. Thanks for your help!

[Franky_RedWine]

Technically, viscosity is defined as resistance to flow. Commonly though, we think of it as an oil's thickness. To be more specific, it is the thickness of an oil at a given temperature. The plot thickens (pun intended).

The viscosity of an oil could be reported at any temperature, but to standardize things, most laboratories report either a low temp (100F or 40C) or a high temp (210F or 100C) and stick with either Fahrenheit or Celsius. The standardized temperature reading allows us to compare apples to apples for judging the thickness of the oil.


continue here.. http://www.blackstone-labs.com/oil_viscosity.html

I tried alots of oils like royal purple,mobil1, castrol, motul. So at this moment the best oil that I tried is MOTUL v300 competition 15W50, very good for heat weather conditions, here in my country(sicily island). Chenge it every 6-7000 km and you will be the best lubrification for 1zz engine turbo ;)