Join Date: Jun 2001
Location: Central Minnesota
Thats a tougher question to respond to but I will take a stab at it.
The new 'higher mileage' petro oils are more than likely going to be more stable in their weight so as not to 'thin' out when it gets hot. The thinner oil is more likely to go past valve seals and weak gasket leaks. Thats just my guess since none of the petro companies really go to much into how it works, they just market it as 'high mileage oil'.
I would never recommend anyone running 50wt oil in a normal car engine. Sure the pump will pump it but as the engine goes thru warm up, dispersing condensation, putting up with blow by etc, that 50wt will break down sooner than a 10w-40 that moves or flexes with the temps. There are still alot of 'old school' guys around that think thicker is better just as they think a bigger bullet is better in hunting. Not so, its the placement that counts.
A drag racer might run 50wt but they dump their oil after each run most of the time so its not an issue.
Many draggers now are running synthetics and going a whole weekend on one change of oil if they dont tear into the engine, dislodging wear metals and contaminating the oil.
The modern syn's are a true engineering marvel. molecules are all standard size, they can beef up the additive packages to do what they want, but it all costs money. When it comes to a $3000 rebuild of a small block or a big high power motor for racing, does spending $50 for oil or $25 sound like better insurance that its running at its peak HP ?
I highly recommend annual oil analysis also, to help people know how their power plant is working, what might be wearing out and if the oil is holding up. Again, cheap insurance at another $25 to know that maybe a ring or bearing is starting to go, you can now cure the problem before it causes major damage.
Not sure that explains it completely but thats my 2cents worth from over 25 years of running syns and seeing them made. [img]graemlins/thumbsup.gif[/img]
Click..is Jim..former owner of a 69RS-LM1 350/255 - 700r
"There will come a time when you believe everything is finished,
That will be the beginning." Louis L'Amour