Synthetic Oil
Here's What I Found.
I broke my engine in using Castrol 20w-50 oil. By running a Cylinder Head Temp. Gauge, and an Oil Pressure Gauge, I have been able to monitor my engine's temperature's very closely. With the 20w-50's or Straight 30 weight oils, my head temp stayed around 325-350 degrees, and my oil temp would slowly climb to around 240 if I let it go long enough. With either 20w-50 or Straight 30 oil, I would balloon my filters in the morning if I went higher than 4000 rpm. For the hell of it, I tried a 5w-50 oil. When cold, the oil acts as a 5weight. When fully warmed up, it acts as a 50weight. Problem was, it is only avaliable in Full Synthetic. Every VW guru you talk to tells you to stay away from Synthetic oils. They dont cool as well. So they say. I tried it, to see what my oil pressure readings would be with this 'wild' viscosity. What my oil temperature did was what I expected. My oil temp dropped over 30 degrees. If you talk to any VW guru out there, they'll tell you it's because it isn't taking as much heat from the heads, so now your heads are running hot. BUT, with my Cylinder head temp gauge, I was able to see that my head temp hadn't changed a bit. Where am I checking my oil and Cylinder head temps? Cylinder head temps are under the #3 spark plug, and the oil temp sender is in the pressure reliefe valve. Also, oil pressure readings are great. If I climb a steep hill, and get the oil up to the 220 degree range, I can still idle at 700 rpm with over 15 psi, and have 45 psi at cruising. The oil, if you are wondering is Quakerstate 5w-50 Full synthetic. It comes in a clear bottle, so you can spot it easily if you want. Another point of reference, Porsche recommends that all it's AIRCOOLED 911's use full synthetic oil. I say, do your own testing, and find out what works best for you. YOU are the person in charge of your car, do to it, what YOU FIND works best for it.
