Originally Posted by four winds
Now I see this one Music
and capngeo referenced is for pre 2007 engines.
The one I posted a link to is for post 2007 engines.
I think the OP is likely to stick with conventional oil considering the stated desire to use a qualified off brand, if I understand correctly. (Rotella 15-40 is readily available and proven)
For me, I think it's safe to assume synthetics are "as good" as conventional oils, at the least. With a couple of possibly distinct advantages, remaining cleaner during the interval and allowing a longer interval if circumstances come up to prevent an on time change, I could be swayed.
But, if it stays so clean where are the contaminates going? Do the contaminates come from combustion by-products, or from the breakdown of conventional oil?
What might be the possible down side of switching to synthetic after 1800 hours and many years using Rotella?
I've always thought the dirty oil is contaminated by carbon compounds(?) from the fuel
First, let me get the disclaimer out of the way and then I'll try to explain.
While I am a certified tribologist (I'll save you the trouble of looking it up: Tribology - Wikipedia, the free encyclopedia
), I do not work, nor am I affiliated in any way to a petrolium products manufacture, except as an end user and a PdM professional.
The advantages of syntethics over mineral oil aren't percieved, they are fact
and backed up by every leading lubrication product producer with years of data to prove it. That said, let me explain in the simplist of verbage.
Syntethic oils are produced and blended with PAO (polyolefins). To put it simply, PAOs make syntethic oils more slippery and inprove the lubricating film properties. Since PAOs bond with the metal surfaces of your engine
, there is little or no metal to metal contact and thus MUCH less wear products in the oil, which in turn means cleaner
oil, and longer oil life. Additionally, most synthetics have better additives which reduce/remove water
from your oil (minimizing corrosion) and clean the interior
of your engine
. Since your oil carries the wear products to the filter, and syns are easier to filter than mineral oils, that results in the contaminates getting left in the filter. Since PAOs help the oil bond with the metal, the interior
of your engine remains coated with lubricant MUCH, MUCH longer than with mineral oils. This in turn means your bearings, etc remain lubricated longer and less wear when starting your donk after it has been sitting for any period of time. Another VERY important benefit of syn oil, it maintains it's viscosity over much larger temperature ranges than mineral oil. I.e. the synthetic oils will still flow normally even if the temperature is very cold or very hot.
There are two basic reasons you need to change your oil on a regular basis. Additive depleation and the oil viscosity has increased too much. As oil is used in an engine it gets dirty over time, dirty oil has a higher viscosity (thicker) than new clean oil.
There are other advantages, but again the major advantages are better fuel economy, less corrosion
, cleaner oil, longer oil life.
Engines and rebuilds cost a lot of money
, synthetic oil costs a few bucks (pounds, euros, etc.) more than mineral. Your call.