Synthetic Oil

So you have a 7 year old car with no miles on it?
Castrol Magnatec 5w30 synthetic engine oil is best for use in common rail diesel engines of small capacity employing a DPF, (Diesel Particulate Filter). Just buy your own and tell your mechanic to use it when he does the service.(Castrol are Hyundai's choice of oil manufacturer here in Australia). After it has done over 100,000miles. You could switch to 5w40 with no ill effects. Slightly 'thicker' oil for older engines requiring the same protection as 5w30.

Thanks for the advice. My car actually is close to 100,000 kilometers, thats about 66,000 miles. But is going great. So I think i'l go for the 5w40 about now only or 5w30 is fine? Can you also give me some opinion on using a petes tuning box for improving the performance of my car.I'm already using a petes air filter.