Thank you all for the info.
I'm not experiencing any issues with vehicle. The vehicle itself was maintained properly, with all oil changes at VW dealerships. My concern is the oil changes were done every 10k miles, which the factory interval. I myself prefer 3k-5k mile intervals. There has been a lot of info lately stating that 10k intervals are not the best, even though that's what the manufacturer recommends. But looks like I'll wait for the 5w40 and take it from there. Thanks again lads!
Good to hear that there are no engine issues to report. There are engine oil flushes available to clean an engine internally that may have sludge build-up but it's often better to use a quality oil that has natural cleaning action so you don't load the oil filter with a mass of sludge that can plug the filter and force the oil bypass to open which then pumps the dirty oil thru the engine unfiltered.
Hear's the executive overview on long OCIs... They are intended to reduce the quantity of drain oil, viewed by some folks as an environmental issue. That being said VW/Audi/Porsche conduct extensive engine testing to define the oil properties required for their engines to operate properly long term. Long term in the auto industry is typically a min. of 100,000 miles IME.
The 10K OCI specified for U.S. model VWs is actually much shorter than the extended 15K-20K specified for some Euro models or a variation of same via an in engine oil use sensor and algorithm. To safely handle these extended OCI's Euro oil suppliers had to develop durable oils with additional quantities of the additive package. Oil doesn't wear out per se the additive package is consumed over the course of operation.
So the bottom line is that in typical use applications the factory OCI recommendations are perfectly fine if you use the correct VW spec oil for your specific engine. In severe applications like for instance towing a trailer all the time or taxi service in a metro area, then changing the oil sooner than the recommended service interval COULD be prudent.
There is a very easy and scientific means to know what is a safe OCI for any engine and that is a Used Oil Analysis, (UOA) test. This test tells exactly what the condition of the OIL is and if it is suitable for a longer OCI. These tests typically cost $35-$60 in the U.S. depending on what UOA lab you use. Changing the oil more frequently than necessary provides no benefit to the engine, it just increases maintenance costs. However not using the correct spec oil for your engine CAN prove costly. A specific oil might be the best oil available but if it's chemistry is not suitable for your specific engine then operational issues can occur.
Using the incorrect oil and changing it weekly will not properly protect your engine if it does not have the correct chemistry.
I have been using UOA on all of my German vehicles since the 90's. For me it confirms that my OCI is correct for the application and the VW spec oil that I am using. And for the record a UOA does NOT tell you if one oil reduces engine wear vs. another brand or viscosity. To accurately determine engine wear vs. specific oil type/viscosity requires thousands of dollars of industry testing that a $35 UOA is not intended for and cannot provide.
A UOA tells you if the oil is still good for longer service and what contaminants are in the oil such as H20, fuel, metals, etc. That is all it can tell you.
I have used/tested a number of UOA labs over the past decades and I can recommend Titan Labs in CO and SPEEDiagnostix if you want a slightly quicker UOA result but at a premium price. There is another popular UOA lab often recommended in VW / oil forums that I do not recommend as I have found their use on non-std. SAE J300 viscosity references for used oil and other issues in their UOA analysis to be inconsistent with industry standards. So I do not recommend them. I have NO association with any of these UOA labs.
Sorry for the long response but using the proper oil in an engine is important for long term reliability and minimal wear. There is a lot of conflicting info. online so hopefully this eliminates a lot of the "noise".
