I have just bought an 04 reg 2.2 direct Signum with just 25000 miles on it.

My mate who has an 02 reg vectra 2.2 recons the earlier engines have a problem with oil starvation to the camchain and he was advised to fit fully synth oil in his.

My Signum was due a service so i decided to give it an oil change
I have just changed it for Silkolene 5w40 fully synthetic.
Is this ok?

Sorry if this info is on here somewhere but i have looked