[BoomerGuy]

Oil is oil and we all know why VW changed their oil specs.
It is because the thinner oil VW has switched to recommending, allows them to claim high gasoline mileage.
And that has cause premature failure of any place the oil is not under pressure, like chain slippers, camshaft lobes, etc.
The best way is to use better oil than VW is recommending, which is thicker viscosity, not 502.00 spec.
They are NOT recommending the best oil at all, but the oil with the highest mileage rating capability.
Nothing in the hardware has changed, so there is no good new reason for the new oil spec.

Are you saying that VW spec 502.00 is low viscosity? Exactly what do you mean by, "use better oil than VW is recommending"? I honestly don't understand your comment, especially the part where you say, "Oil is oil".
.
My 2008 VW Rabbit 2.5 has always been fed VW spec 502.00 in various brands of full synthetic, including Castrol, Amsoil and Mobil1 - all in 5W/40 viscosity. With over 160K miles on the engine, it burns no oil between my 5K mile change intervals. I always use the VW recommended Mann oil filter as well. My outside temperature ranges from -20 degrees F in the winter to 100 degrees F in the summer.

 

[BoomerGuy]

Not to pile on here.
This serves as a good example of why when you are first getting your hands dirty servicing your car it is quite beneficial to have an experienced hand either showing you the way or following behind to check your work. As we see here, rookie mistakes can have nasty consequences.

The very first oil change I did when I was just a pup, my brother-in-law was there to make sure I did not screw it up. His words.

My brother-in-law taught me so much about life and working on cars. Still now, all these decades later when I come to a fork in the road or I am stumped I will stop and say out loud.. What would J.S. do?

He has passed now, when I see some of the hand tools he gave me, sitting in my tool box I remember him warmly.

fat biker

This reminds me of my youth in the 60's when I bought my first car, a used MG. My brother-in-law who was 11 years older than I was and a very experienced mechanic taught me how to do my own work and he made sure that I got my hands dirty. To this day, when there is a job I need done on any of my vehicles which is beyond my capability, I am not too proud to pay for a local friend who is the lead shop technician/mechanic at a dealership. He has been there for over 30 years and he is the one who gets sent off to school to learn the newest technology and returns to teach the rest of the mechanics. Fortunately, I am allowed in the service area and watch him work on my vehicles so that I can learn. I am more than willing to pay for this because not only do I get the job done right, I learn something every time.
He owned my Rabbit Mk 5 2.5 for 10 years before I bought it. I do the simple stuff and he does the complicated stuff. Although my Rabbit shows its age, it runs like brand new and has no mechanical issues of any kind. On the other hand, there are those little German gremlins in the electrical system.....

 

[BoomerGuy]

Maybe... regarding whether we should be having it here. But as GTI's pointed out, OP seems to have quit this thread long ago (without telling us what the outcome was); so we naturally turned to other things. I'd actually prefer for this coolant discussion to be in its own thread, because I think it's critical for VWs...but we're already into this here...

I agree with the importance of the coolant discussion. I am VERY careful with all of the types of coolants in all of my vehicles. There are different specs for a reason.
Regarding my 2008 Rabbit Mk 5 with the 2.5 engine, when I bought it from the previous owner, I wanted to start fresh with a new and dependable coolant for the best coolant specs at the time which was G12++. I had a professional mechanic who is very familiar with VW/Audi products use a professional flushing machine to completely change the coolant. This prevented any mixing or introducing air into the system. Since then, I've had the same mechanic replace my water pump and thermostat while inspecting the internals of the cooling system. Absolutely no damage has occurred since the flushing/replacing of the current.

Even though the G13 and newer specs of coolants will be coming onto the market, I will stick with my G12++. Just to be on the safe side, I have written on the reservoir bottle, "USE ONLY G12++ COOLANT.

You can choose whichever coolant you want, but this is the info on what I use: Valvoline/ZEREX G40 Euro Pink Coolant

When the VW Rabbit Mk V (2006-2009) was made, the German VW coolant standard specified for it was VW G12 standard. There is now an improved coolant for it which meets the German standard VW G12++ which also meets the worldwide standard BASF G40. Valvoline/ZEREX G40 Euro Pink coolant meets this newest worldwide standard BASF G40 and German standard VW G12++.

BASF G40 standard coolant has only existed since 2008 and has a lower starting pH and less reserve alkalinity. When creating this coolant wanted maximum aluminum protection, BASF originally intended it for use in only VAG* passenger cars.

BASF G40 (VW G12++) works with cast iron, aluminum, other light metals and the combination. Volkswagen recommends it for all of their vehicles made after 2005 (Mk 5 and newer). A complete flush is necessary when replacing any older coolant with a newer, different one.

 

[BoomerGuy]

Maybe flushing machines may vary, but I watched the flushing machine as it worked. Three gallons of the new PINK coolant went into an empty tank while the other receiving tank was completely empty. As the new PINK coolant was pumped in, the old coolant was pumped out. The tank was connected to the intake and discharge lines at the radiator. There was no blending of the two different colors in the receiving tank or in the reservoir in the engine bay. I would compare it to dialysis. I can't remember the brand of the machine. The entire procedure took less than 15 minutes. When the job was finished and the machine was turned off, the "new" tank was empty and the "old" tank was full of the old coolant which was its original color.
Like I said, when my thermostat and water pump were replaced, there were not solids or corrosion of any type.