B9.5 Engine Oil 0w-20 vs. 5w-30 controversial

[AutoRacer100]

Hi All,

For those of you who are planning to keep their car for long term. Are you concerned that Audi manufacture recommended 0w-20 motor oil will reduce the longevity of your SQ5?
My apologies for bringing up this topic which have been discussed in the past. I have read the threads and watched videos online. The video posted by VAG Technic (below) concerns me the most as well as videos regarding metal shavings in the oil filter for B9 SQ5. People said it is normal to find metal sparks in the oil filter. But it doesn't make sense to me to see that happening in our car. I wanted to keep my B9.5 SQ5 for a long time and concerned about this. I feel the only way to minimize the engine wear is to switch the motor oil to a thicker one (i.e., 5w-30) in the summer. The B9.5 SQ5 tend to run a little hot and my car's temp was at 225F when the outside temp registered at 100F. The car was not even stuck in the traffic. So I feel it was pretty hot for the car. I've looked online there is no 5w30 oil spec at 508 but 507 or 505. I'm not sure the spec 505, 507 or 508 makes any significant difference in terms compatibility. The link below is to the VAG Technic video. One of the B9 RS4s has engine fail at 26900 miles. It's scary to see a such high end car fails at such early age. I'm interested to know who on here been using 5w-30 oil for their B9 or B9.5 SQ5 and any feedback on the result is appreciated.


https://youtu.be/sd0dIE7VCKk?si=M1F2d2AKOZWSs823

[GoCougs1234]

No offense intended, but it's only controversial for those not knowledgeable with how engines work, particularly engine oil. There should never be concern WRT using the oil the manufacturer has specified and otherwise it's a really bad idea not too, esp. modern engines that have very specific additive requirements (like VW509 for the B9/9.5 3.0T EA839).

[Smac770]

508.00 for the CWGD 3.0T, 504.00 for the DECA 2.9T. 509.00 is the specification for diesel applications. Why are they always in pairs for the same oil, but with different numbers? 502/505, 503/506, 504/507, 508/509. No idea.

Of course there's no 5w30 for 508/509. The design of the spec is such that it effectively mandates 0w20.

There's nothing out of spec being at 107°C for a burst. And changing the oil is not going to do anything. That effective operating temp is controlled by the coolant management. The target is up to 105°C under partial load and up to 90°C for higher loads. But "reached operating temperature" is 100°C. These are coolant temps. You want to help the temps, turn the A/C off and crank the heat. :-)

The oil cooler thermostat doesn't even open until the oil reaches 115°C, at which point oil is then cooled by the coolant.

As for metal in the EA839, you need to read more about the rocker arm thing, which is what that video is about. Do you have a MY18 CWGD engine? And why would anyone be running 0w20 in a DECA engine? That's not the correct oil for that engine, not in the US at least. But these are UK, that's up to whatever Audi UK says to run. There's also the question if the UK vehicles run the flex interval or extended interval service config. And did the video ever say what the actual model years of the two involved vehicles were?

You want to do the most you can for your engine? Do 5k oil change intervals instead of 10k, and use the oil Audi says to use in it.

[GoCougs1234]

Interesting to know the thermostat opening temp for the oil cooler (115 dec C/239 deg F). That tracks with exactly what I've seen - I can get oil temp up to ~240 deg F but never beyond. That explains that!

[AutoRacer100]

Thanks for the replies! I will stick to the 0w20 oil. So the spec 505, 508 and 509 are types additive in the oil?
Comparing OEM oil with Liquid Molly and Motul oil. Which one is the best? Motul is the most expensive among the three. Not sure why with the price jump.

[Smac770]

Those 5xx numbers are VW oil specifications. 505, 506, 507, 509 are oil for diesel engine specs. 502, 503, 504, 508, 511 are oil for gas engine specs. https://www.blauparts.com/blog/vw-oil-specs-german.html

502 5w40 was the general base line at the start of the century.
503 5w30 was introduced for the extended/flexible service interval (running longer than 10k mile OCIs). That got replaced by particulate filter friendly 504 5w30.
Now there's 508 0w20, which really is only about efficiency over 504. And even 504 has been shifted to 0w30.
511 0w-40 is for the high output 4.0T, where a particulate filter friendly 40 weight oil was wanted.

Also note, the full spec is 5xx.yy. yy is often 00, but not always. For example, 508.88 (a Brazil market spec) has no relation at all to 508.00 (the spec for the CWGD). Why are they both 508? No clue.

So while 508 is really just an efficiency stab at 504, and the EA839 DECA uses 504, you can't just toss 504 in the EA839 CWGD without confirming the bearing tolerances and other engine part choices are compatible with the different oil characteristics. But, as the engine ages? Maybe switching to 504 at 100k wouldn't be foolish? https://www.mobil.com/en/sap/persona...bout-viscosity But after saying thicker oil for older, they CYA with "never use the wrong viscosity".

As for which 508.00 0w-20 vendor, Castrol vs Mobil vs Liqui-Moly vs Motul vs whatever, that's the same kind of debate as blonde vs brunette vs ginger.