Buy a good, not cheap oil
There are cheaper oils but why save $10 for the risk?
At first, I was reluctant to purchase it as I thought that it would not be as good as the most expensive 0W 40 brand that I was using before. After comparing the specifications and physical characteristics of the group IV oils, I found that there was no much difference.
I am so glad I switched. My Peugeot 307 loves it and it doesn't affect the catalytic converter. The car seems to be running a lot smoother and quieter. The manufacturer recommends oil interval at 20,000 kms but I changed mine at 10,000 kms. This oil is great and at a great value. Would recommend to anyone who loves their car!
Although a little expensive, this is a very good oil indeed. Excellent detergency, quieter running, increased fuel economy and zero oil usage. Not cheap, but you do get what you pay for!