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What happens when a dino dies with plant matter in its gut?
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What happens when a dino dies with plant matter in its gut?
What happens when a dino dies with plant matter in its gut?
As someone in the lubricant engineering field I'm always amused by any threads pertaining to oil. I see some good answers and some that are totally out there and ridiculous.
heh heh, "lubricant engineering".......
5W40 is still too thin for most of our bikes (except in the winter).
Paul, with respect, that is not correct.
When you see a W on a viscosity rating it means that the oil viscosity has been tested at a colder temperature. The numbers without the W are all tested at 210?? F or 100?? C which is considered an approximation of engine operating temperature. In other words, a SAE 30 motor oil is the same viscosity as a 10w-30 or 5W-30 at 210?? (100?? C). The difference is when the viscosity is tested at a much colder temperature. For example, a 5W-30 motor oil performs like a SAE 5 motor oil would perform at the cold temperature specified, but still has the SAE 30 viscosity at 210?? F (100?? C) which is engine operating temperature. This allows the engine to get quick oil flow when it is started cold verses dry running until lubricant either warms up sufficiently or is finally forced through the engine oil system. The advantages of a low W viscosity number is obvious. The quicker the oil flows cold, the less dry running. Less dry running means much less engine wear. The only time the 5W-30 oil is "thin" is at cold start up conditions where you need it to be "thin."
Even running 0W oil will not melt down our engines. The key number is the last one, at operating temperature. In practical terms, the engine starts easier (helps battery life!), and as the engine warms, the polymer chains in the oil thicken it for proper operating temperature rating.
...and if you read the oil/temp usage charts, they will tell you that a xx/40 wt oil is recommended up to about 75 degs or so (don't have the charts in front of me at the moment, so that temp could be off by a few, but not many).
don't know about you, but i do a TON of riding at temps vastly exceeding 75 degs.
a 20W/50 oil is temp rated from 20 degs F up to 105 F--- temp ranges that are rarely exceeded by most of us.
I will support PG's statement that a xx/40 wt oil is, under most circumstances, too "thin" an oil for our bikes.
...and if you read the oil/temp usage charts....
They will tell you what is recommended for your specific bike. I would not extend what you read for your bike as a general rule applicable to all. Example:
Same oil, almost the same bike, 3 different ranges.
- 2010GS: no chart, table says 10W40 for >= -10 ??C, Castrol GPS 10W-40 >= -20 ??C, no upper limit given
- 2008GS: 10W-40 -10 ... 30 ??C is listed in a table
- 2004GS: 10W-40 -20 ... 30 ??C noted in chart form.
BMW sells oil??? People are too OCD about this stuff, it is an internal combustion engine, they have been around for years, cheap oils today FAR exceed the best you could buy 20 or 30 years ago.
Your response makes sense if you have a 20 to 30 year old bike. In that case yes the oil is way better than when the bike was made.
On a new bike, the manufacturer, when it designs the engine, takes in to account the quality of oil available, and specs out the oil based on the then-current API classification. They probably assume you won't go out looking for a case of 30 year old oil, but just in case will tell you the classification of oil they expect you to use.
As long as the oil you are using meets or exceeds the API classification, it is SAFE to use, you will NOT void your warranty if you are using the proper API classification and appropriate, recommended viscosity.
In the case of my bike, a wedge 4, things are slightly more complicated due to the intregal engine/transmission, but again I know if I use what is stated in the manual "Mineral oil API classification SF to SH" it is OK to use. If they do come out with a higher class than that it is also OK to use. Anything beyond that is strictly an opinion (mineral vs synthetic, brand, etc).
And once the SG oil is no longer produced, than what do you do?