Suking Petron Station back then for me was usually the 2 Petron Stations along Quezon Avenue near Araneta Avenue in QC. One is almost opposite Sto Domingo Church and the other is opposite Mistubishi Quezon Avenue/St Peter Funeral Home/Chapel. Both weren't flood prone properties themselves, just the areas near them, or a few hundred meters from them. =)
After the rusting incident, I stopped using Petron altogether.
But on that note, I recall when Volkswagen was going to reenter our market when we were still stuck with Euro 2 standards, there should have been an article mentioning that the diesel quality here had some problems. I assumed they were just not naming Petron specifically back then.
Here is the first article I could find about diesel quality concerns of Euro makes.
More diesel-powered passenger vehicles upcoming
Except from the Article published back in 2015:
"Fuel quality concerns
Carmakers say that while local fuel is suitable, concerns remain. Magsuci of BMW says that high particle count is one reason why not many European brands are able to bring in their diesel engines, and another is the high sulfur content."
So I just equated in to that as well, since the fuel rust issue, especially of fuel tanks were popping up for previous gen Montero and Fortuner owners. Asked the service/casa of both brands along Quezon Avenue and they were receiving quite a number of them. Mostly the owners reported fueling from Petron with some outliers from Shell, but that is second hand info relayed by the service manager(s).
I only can confirm my own fuel use as well as my friend's. I suffered the check engine/rust detected back in 2013, near the end of my 3 year warranty period so I was able to claim it under warranty. My friend got his check engine issue just a few months later around early 2014 (he got his Monty a year later than mine, so his tank was also replaced under warranty) He usually gasses up around Manila area but I don't know which exact stations he used.
*Wh1stl3r - this was back when Petron still sold Euro 2 diesels. How different their current Euro 4 mix is, I don't really know.
On our 10 year old or more gasoline vehicles, the issue I've found is that I have relied on putting in 95RON instead of just 91RON (the specified required fuel) to remove shuddering from the car. It is usually really noticeable if we haven't started the car for more than 36 hours, or say going 2 days or more before we start it.
This has been what we found was consistent to remove the shudder (almost to the point where it feels like the engine would die while idling) for 2003 Xtrail, 2008 City and the 2009 Altis. All have specified recommendation of using 91RON (or even 89 I recall for the Altis if I'm not mistaken). We consulted a mechanic when it was an issue on the Altis and Xtrail and he told us to use 95RON instead of 91RON, saying something about water content from the biofuels separating when fuel is left standing in the tank for too long if it's parked for a long time (or basically not in daily/frequent use). It did really work. But as to his reasoning, I haven't really been able to find an article specific to it but it just worked for us, no need to change any part really.
The City had other issues when I brought it in to Honda. Hehe! You can read about that in the Honda or Toyota thread I think. Again, resolved as well.