Now the octy is on variable service and i have always topped up with 506/1 castrol slx longlife 11 to 506/01 . Now that i can not get that oil is it still ok to mix with the new 507 longlife . Had a service 2 months ago and do not know if they filled with either spec , but it was longlife .:confused:

507 00 is backwardly compatible with 506 01 and will be fine for your car (PD130) on variable service intervals. See the sticky below for more info on oils available.

http://www.briskoda.net/forums/new-octavia/what-oils-meets-specs-vw-504-00-507-00-a/55476/