1) I think it is absolutely fine to pump fuels from
different companies. But people just don't like to change company,
dunno why. Petrol is petrol, no difference in chemical make up even
if it's different companies like Shell, Caltex, Esso, etc. The only
diffference is the RON rating.
The only thing that's going to harm the engine is too low
octane, causing the engine to knock. So be sure to read your car's
manual to find out what's the lowest RON rating your car's engine
can take. Usually the higher the capacity the engine is, it will
need fuel of higher RON rating. Small engines maybe minimum RON92,
bigger engines maybe minimum RON95.
2) Not too sure whether Shell or Esso is better. But a lot of
people say Shell's petrol is more powerful, no matter is it RON95
or RON98.
And I think this is because when you see the fuel says RON98, it
does not necessarily mean the fuel has an octane rating of exactly
98, it might be a bit more or less. RON98 is just naming the fuel.
So maybe Shell's Formula98 has a higher octane maybe at 98 point
something and maybe other companies' RON98 fuel only has 97.9807
(example only).
This is just my simple explanation, explaining why maybe you'll
feel Shell's fuel is more powerful than other companies' fuel of
similar rating of RON98.
But I personally feel Shell's fuel is the most powerful among
the different petrol companies in SG.
