Originally Posted by nicknick

Personally in the Zed, I'd change it at 1 thou, then every 5,000kms with an ester based synth, like Motul. Bare in mind though that Ester based oils are not desgined for long life but they do excel under high stress and heat but after 5,000km even according to Motul the oil should be changed out. for the Zed I'd go the 5w-40 in the Motul 300v range, expensive but good.