Fuel grade petrol has additives which might cause unwanted effects.
Actually in region where I live we have a cheap & pretty common solvent easily available (sold at hardware stores, etc) called "Petrol Galosha" (Russian). It's basically a petrol without fuel additives (with octane number somewhere around 52 as Wikipedia article mentions) and dearomatized.
I.e. it's much more "clear" of additives and are traded as a solvent. So it's pretty common here to be used as a flux cleaner for PCBs. I've used it dozens of times to clean PCBs with components (surely ones which allows liquid clean, not something like humidity sensors, etc) and never had any issues. In fact it clears PCBs off the flux traces much cleaner & quicker than a alcohol. But I've still switched to isopropyl alcohol due to the scent it had (even dearomatized it had a distinct scent of petrol).
I've noticed that this was a question from a few years ago. But probably this might be an interesting read for someone in other regions.