I was in Paris yesterday (Oct 23rd, 2021), and during my pre-departure check, I noticed the engine oil level was at the lowest mark of the dipstick. I don't understand how it went from mid to low between Houston and Paris, but it can only be an erroneous reading on my part.
I only found this thread today (Oct 24th).
O'reilly could not provide any help.
When I think of Oil, I think of standard. Each oil manufacturer will advocate they have the best oil for your application.
So how can we judge? how can we compare? beyond the SAE classification, should we check which standard(s) the oil conforms to.
Our good friends at the API will provide us will invaluable information about the current standards: here!
Here is the list of Oil categories for Gasoline Engines; the current moniker is "SP". The API standard for 2004 was "SL", and "SJ" earlier.
"JASO" (Japanese Automotive Standard Organization);
JASO T503 latest issue is JASO-MA2 (2006) from JASO-MA, for motorcycle engines that use the same oil in clutch, engine, gear box;
JASO-MB for motorcycle engines with dry clutch, separate oil for gear box and engine.converters.
JASO-MA2 for motorcycle engines equipped with a catalytic converter.
SAE (Society of Automotive Engineers) Automotive Lubricant Viscosity Grades: Engine Oils – SAE J 300, Dec. 1999
Bottom Line, I picked Castrol Power1 because it conforms or exceed the requirements of API SP, JASO-MA2, is classified as SAE 20W-50 which means I can start my engine safely up to -20 degC (-4 degF).
Castrol has a Product Data Sheet that lists the Power1 oil characteristics: https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/674DB92D31BE7CE0802583050045159E/$File/BPXE-A3QE84.pdf
Other oil brands, don't necessarily gives you as much information; here's an example with Mobil: https://www.mobil.com/en/lubricants/for-personal-vehicles/motorcycles
No standard specified, no product data sheet. It does not mean the oil is not as good as the others.
Another Oil brand to consider, is AMSOIL; https://www.amsoil.com/lookup/motorcycle/2004/moto-guzzi/v11-sport-v11-lemans/1100/?volume=us-volume
And they have a product data sheet: https://amsoilcontent.com/ams/lit/databulletins/g2090.pdf
They lists the previous API Standards, but not the latest SP, they also conform to JASO-MA and MA-2.
Just for fun, let us look at comparable reported results:
Kinematic Viscosity @ 100°C, cSt (ASTM D445): Castrol=19.99 mm2/s; AMSOIL=18.5 cSt (Centistoke) units are comparable.
Kinematic Viscosity @ 40°C, cSt (ASTM D445): Castrol=152.9 mm2/s; AMSOIL=132.8 cSt
Viscosity Index (ASTM D2270) : Castrol=151 AMSOIL=156
Flash Point °C (°F) (ASTM D92) : Castrol= 253 AMSOIL=228
NOACK Volatility, % weight loss (g/100g) (ASTM D5800/CEC L-40-A-93 ): Castrol = 4.8% AMSOIL=4.2% (not a direct comparison as Castrol did not use the same ASTM standard than AMSOIL).
So, which one between the Power1 and AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil has the best characteristics?
The Castrol has the highest viscosity results under D445 at the reported temperatures.
The AMSOIL has a better viscosity index. higher number is better, but does not tell all.
The Castrol has a greater flash point.
Go figure....