5W-20 or 0W-20???
#51
07-01-2009, 04:55 AM
Re: 5W-20 or 0W-20???
Ken,
I remember the report but synthetic oil has improved a LOT since that time. Those oil formulations required the engine to be "broken in" using dino oil to ensure the rings were seated correctly. If you are running short oil change intervals (OCI) of 3,000 to 7,500 miles, there is not that much of an advantage to synthetic oils except at temperature extremes.
At very cold temps, the thinner oils (0W and 5W) will flow better using synthetic as opposed to dino oils in equivalent grades (5W is the thinnest dino). At the other extreme, in very hot weather, synthetic oil will not degrade and loose the ability to lubricate the engine as will "dino" oil.
Take a look at the worlds high performance cars and the oil that comes in them as factory fill. After checking that scenario out, do the same thing with new cars running extended OCI's of 10,000 miles or more. I doubt that ANY of them recommend dino oil. With the current economic situation, if they could run dino oil, I'm sure that the manufacturers would because of the cheaper cost to them to produce the car.
I do my own maintenance work and for the difference in cost (less than $10.00 per oil change) of dino to synthetic oil, I will continue to use my trusty Mobil 1 5W-20 oil.
I remember the report but synthetic oil has improved a LOT since that time. Those oil formulations required the engine to be "broken in" using dino oil to ensure the rings were seated correctly. If you are running short oil change intervals (OCI) of 3,000 to 7,500 miles, there is not that much of an advantage to synthetic oils except at temperature extremes.
At very cold temps, the thinner oils (0W and 5W) will flow better using synthetic as opposed to dino oils in equivalent grades (5W is the thinnest dino). At the other extreme, in very hot weather, synthetic oil will not degrade and loose the ability to lubricate the engine as will "dino" oil.
Take a look at the worlds high performance cars and the oil that comes in them as factory fill. After checking that scenario out, do the same thing with new cars running extended OCI's of 10,000 miles or more. I doubt that ANY of them recommend dino oil. With the current economic situation, if they could run dino oil, I'm sure that the manufacturers would because of the cheaper cost to them to produce the car.
I do my own maintenance work and for the difference in cost (less than $10.00 per oil change) of dino to synthetic oil, I will continue to use my trusty Mobil 1 5W-20 oil.
#52
07-01-2009, 04:23 PM
Re: 5W-20 or 0W-20???
The Toyota HSD hybrids make extensive use of a splash lubrication system to cool and lubricate the drive line components when the ICE is off. Part of this system flings oil from cavities on some of the rotating components to other drive line components that do not touch the oil bath. The thinner synthetic oils perform better in this situation as they have a lower viscosity when cold, and superior surface adhesion whether hot or cold.
The oil in a hybrid is exposed to wider temperature ranges while operating also. The ICE in a hybrid can be off for several minutes in city crawls or on extended downgrades. The oil can cool relatively quickly and then heat up again when the power comes on once you hit the freeway or climb the next hill, and the engine oil pump starts circulating it through the engine as well as the HSD drive. Synthetic oils tolerate these temperature changes better and remain more effective as a splash lubricant when cooled due to their lower viscosity at those temperatures.
That -- was the reason for the Toyota TSB.
( I'm surprised that you didn't comment on this aspect, Stan. I know you are aware of it.)
The oil in a hybrid is exposed to wider temperature ranges while operating also. The ICE in a hybrid can be off for several minutes in city crawls or on extended downgrades. The oil can cool relatively quickly and then heat up again when the power comes on once you hit the freeway or climb the next hill, and the engine oil pump starts circulating it through the engine as well as the HSD drive. Synthetic oils tolerate these temperature changes better and remain more effective as a splash lubricant when cooled due to their lower viscosity at those temperatures.
That -- was the reason for the Toyota TSB.
( I'm surprised that you didn't comment on this aspect, Stan. I know you are aware of it.)
Last edited by FastMover; 07-01-2009 at 04:39 PM.
