Synthetic vs. Mineral (petroleum) debate
Welcome to the forum New Monic!...glad to always have people throwing in debating type questions..........There fun!...so let's get to it!
The debate about which oil is better will probably go on for decades to come. The standard petroleum based oil has been used for so long, through so many generations by fathers who taught us that "Quaker State" is the best motor oil for our car; thinking there may be a better motor oil out there, would be unheard of!
When we talk about synthetic oil, in comparison to petroleum oil, we find some unique features. The basestocks in synthetic motor oil are pure. Because they are derived from pure chemicals, they don’t contain any contaminates or molecules that just take up space, they all are doing the job they are designed for, to slip easily across one another. Petroleum oil on the other hand has molecules found in nature that are jagged, irregular and odd shaped and don’t slip quite so easily. These molecules all have differing properties and break down at different times. Some at high temperatures, some at high pressures and some in cold temperatures. Some of the molecules don’t even have any lubricating properties and just take up space until they solidify into sludge or varnish on the cylinder walls or become dirt deposits.
Synthetic motor oil can be designed to do certain tasks. The features include the Viscosity Index, the ability for it to flow at certain temperatures. All molecules are the same size thus have the same characteristics. Thermal and Oxidative Stability, the fact that they don’t contain contaminates that break down at normal operating temperatures. Cold Temperature Fluidity, again there is no paraffin or wax present to inhibit flow at lower temperatures. Low Volatility, Synthetic Oil does not boil off at normal operating temperatures. (Synthetic Motor Oil, Lubrication Basics by Greg Johnson).
But to answer your question about why they only suggest you use the XP-S mineral (petroleum) based oil in their supercharged engines? They do not…..you must have either been mislead or read something wrong somewhere. Let’s see if I can go over this real quick.
From the 2007 4-Tec shop manual it states,
The 2007 GTI, GTI SE, GTX, GTX Wake all use the Rotax 1503 4-TEC 4 stroke (sohc) engine. The technical data sheet states that the lubricant for this engine is 10W40 4 stroke oil with an API classification of SL, SJ or SH. Fuel requirements are for regular unleaded with 87 octane.
The 2007 GTX Supercharged and the GTX Limited use the same engine but is forced induction (supercharged). The technical data sheet on this engine states that it will use XP-S 10W40 or an equivalent approved by BRP and the fuel required is the premium unleaded with an octane of 91%. The XP-S oil is a synthetic blend, not petroleum. The only visible difference in these two engines is the supercharger. If you read the above article about the properties of the synthetic blend, then it should also be known that the supercharger on this engine turns 45,000, yes, that’s forty five thousand revolutions per minute. Now this is where my opinion comes in, I believe due to the properties of the synthetic blend and the rpm’s of the supercharger, this is the best choice of lubrication for this type of engine.
I think one of the most important things about engine lubrication is that once you decide on an oil type, stick with it. Changing engine oil type after the engine has been broke in may have an adverse reaction to the type that was once in it. That too is just my opinion.
Thanks for the question, I love looking into and reading this kinda stuff!..
