Hi Kobus,
There is most definitely a difference.
I'm pretty sure the petrol comes essentially from the same supplier...but the companies modify the fuel with additives and claim their fuel is best and cleans better etc. etc.
I have put in a full tank of petrol with Engen (95 primax), and when we run logs...there is heavy timing pull on the cylinders. (In other words the car pings and then it retards the timing to prevent damage) "Timing pull" can also be seen on dyno graphs...the graph will be very jumpy. (Talking about the GTi)
When we put in BP 95...we run logs again...and then the timing has jumped from -6/-7 to 0 timing. Which is good.
So from now on I only gooi Bp 95...even in my advanced driving course they recommend Bp 95 above all other stations.
Shell was always good...but now with the V power nitro plus...I don't know what they did...the okes are complaining left, right and centre about their cars run bad and severe timing pull even to -8 degrees.
My Gti has been pulling -5/-6 timing for a while now. I have been doing supporting mods to ensure maximum cooling and better spark.
Yes I have gone through a few intakes/sparkplugs/coil packs and different maps and we still couldn't figure out why my car pulls timing so badly.
So in the end...they asked me which fuel am I using and I replied Engen 95 primax...and everyone told me to fill up with Bp two-three times and come log again...
So I did just that.
With exactly the same mods I went to do logging and the timing was zero! (in the middle of the hot day)
I went for a dyna run again and voila! Graph looks much smoother and I made quite a bit more power!
fuel quality is definitely different. I'm sure people will say the same with diesel and give their input.
Ps:
Here is a e-mail I received not too long ago
Petrol is becoming more and more expensive!
My line of work is in petroleum for about 31 years now, so here are
some tricks to get more of your money's worth for every litre.
Here at the Marian Hill Pipeline where I work in Durban, we deliver
about 4 million litres in a 24-hour period thru the pipeline. One
day is diesel
the next day is jet fuel, and petrol, LRP and Unleaded. We have
34-storage
tanks here with a total capacity of 16,800,000 litres.
Only buy or fill up your car or bakkie in the early morning when the
ground temperature is still cold. Remember that all service stations
have their storage tanks buried below ground. The colder the ground the more
dense the fuel, when it gets warmer petrol expands, so buying in the afternoon
or in the evening....your litre is not exactly a litre. In the petroleum
business, the specific gravity and the temperature of the petrol,
diesel and jet
fuel, ethanol and other petroleum products plays an important role.
A
1-degree rise in temperature is a big deal for this business. But the
service
stations do not have temperature compensation at the pumps.
When you're filling up do not squeeze the trigger of the nozzle to a
fast
mode. If you look you will see that the trigger has three (3) stages:
low,
middle, and high. In slow mode you should be pumping on low speed,
thereby
minimizing the vapours that are created while you are pumping. All
hoses at
the pump have a vapour return. If you are pumping on the fast rate,
some of
the liquid that goes to your tank becomes vapour. Those vapours are
being
sucked up and back into the underground storage tank so you're
getting less
worth for your money.
One of the most important tips is to fill up when your tank is HALF
FULL.
The reason for this is, the more fuel you have in your tank the less
air
occupying its empty space. petrol evaporates faster than you can
imagine.
Petroleum storage tanks have an internal floating roof. This roof
serves as
zero clearance between the petrol and the atmosphere, so it minimizes
the
evaporation. Unlike service stations, here where I work, every truck
that we
load is temperature compensated so that every litre is actually the
exact
amount. Another reminder, if there is a fuel truck pumping into the
storage
tanks when you stop to buy, DO NOT fill up-most likely the
petrol/diesel is
being stirred up as the fuel is being delivered, and you might pick
up some of
the dirt that normally settles on the bottom.
Hope this will help you get the most value for your money.
DO SHARE THESE TIPS WITH OTHERS!
