Classic cars often need special attention, and that applies as much to the things they consume as it does the bodywork or trim. In the case of an old air-cooled Porsche, engine oil is an important factor—you need one that stands up to the unique cooling characteristics of the engine and the way the engine works. Thermal load is higher, and oil bears much of the cooling brunt itself—while described as air-cooled units, the engines rely on cooler oil too. Higher compression ratios of Porsche's performance engines further increase the strain.
There can be few better companies to decide what's best than Porsche itself, which has launched a new motor oil for its vehicles in the U.S. market. Porsche Classic Motor Oil is available in 20W-50 and 10W-60 grades and suits all Porsche's old air-cooled models—from early 356s through the 914 mid-engined four-cylinder models, to 2.7- and 3.0-liter plus 911s. That means all 911s are covered, including the 993 model range which preceded Porsche's move to water-cooled 911s in 1998.
Porsche has developed the oil itself at the Porsche Development Center in Weissach, Germany, and it has been tested both in the laboratory and on the road. The automaker says the special oil is compatible with the alloys and sealing materials used in its air-cooled engines, and has high temperature resistance and shear stability. Owners will also be glad to know it's been optimized for protection against corrosion and wear, using zinc and phosphorus compounds. The higher viscosity of each oil compared to some modern equivalents is also better suited to older engines, reducing the potential for leaks and improper lubrication. Owners can buy the oil direct from Porsche—but don't expect it to come cheap...