Rislone ZDDP (Zinc) Engine Oil Additive

Air-cooled VW engines are of an old flat tappet camshaft design, unlike modern engines.  This older design requires using engine oils with high ZDDP (a zinc phosphate compound) content, especially to protect the camshaft and lifters.  Years ago, it was found that ZDDP causes premature failure in modern catalytic converters, so it was reduced significantly in modern engine oils due to smog requirements of the newer cars.  Nowadays, we need to add the ZDDP back into the oil for your older car, or use a racing oil such as the ones we carry here in the store that have the necessary zinc content.  This additive will work great if you chose to use a modern oil. 

We generally recommend using half bottle per oil change for stock engines and a whole bottle per oil change for full-flowed performance engines with an oil sump.