Petronas Dagangan vs Petron Malaysia

There are 2 Bursa companies in the service station sector – Petronas Dagangan and Petron Malaysia. The former is about double the size of the latter in terms of revenue. You may think that this may give Petronas Dagangan some advantage

But you can see from the chart below that Petron Malaysia is no pushover and is able to compete. So which would you chose to invest from a fundamental perspective?