Oil

I'd like to know why CP Performance(possibly other engin builders as well) recomends a 50 weight racing oil instead of a thinner synthetic.

Thanks Karl Dempwolf

Cos if u are running an air cooled VW unit it was designed for thicker oil ( as the unit gets bloomin hot compared to a water cooled engine) thin oil = poor oilr pressure= rapid engine wear = BANG
So stick with the maunfacturers recommended oils for best results.
sae 20/50 was the design oil and good quality oils plus deep sumps and oil coolers do the job nicely on a tuned engine

hope that helps

Magwa

Also the synthetics seem to leak or seep, whereas dino-oil doesn't seem to be as bad.

I used to have the problem of the oil light coming on during hard corners so I switched to a straight 50 weight oil. Problem solved. I also filled the sump so that it is about a quater inch above the full line. Engine seems a lot quieter now. Maybe it is all in my head.

VW, as far as I know, has never recommended synthetic oils for air cooled engines. They don't even recommend multi-weight oils. If I remember right, above 85F (tropical), they recommend 40 weight and down to around 40F, 30 weight.

Things are getting clearer having heard directly from the engine builder who says 20-50 weight is what he recommends. But then the Vintage Owners manual (2002 edition)says to use straight 50 weight. I've got it, 50 weight if you drive in AZ in the middle of summer and the rest of us 20-50, unless you spend your winters driving in Montana. Thanks for your time. Karl Dempwolf

I run Synthetic and have absolutely no problems. I run multi grade 20-50. No leaking, weeping, wear, noises etc. I change it every 2000K. No issues so far.

Doug