I was thinking of using a fully synthetic 5W30 engine oil in a 1.4litre TSI turbo-charge VW petrol engine that normally requires a VW 504.000 approved oil (to protect the catalytic convertor apparently). Royal Purple HPS is not VW 504.000 approved but they assure me that it exceeds VW 504.000 and will be fine. Is there anything else that is better that I should be considering?