You can't use low sulphur fuel, you have to use ULTRA low sulphur fuel. From what I've read the excess sulphur can damage the emissions filters by plugging it since it can only handle a tiny amount. If it's plugged then the car will go into permanent regen mode to try to burn it out and I don't know how that will work, or maybe it will shut down to protect itself. I think the engine will run fine but the emissions controls is what causes the problem.