Petrol types & MPG

[polo-sib]

Here's a question I cannot seem to get an answer for, due to alot of mixed answers. You get your regular unleaded then you get the higher octane stuff such as V-Power, I understand more higher octane equals more power per cycle which in turn will give more MPG.

However I cannot find the true answer does the better fuel give more MPG and is it alot more cost-effective if so?

I've read mixed opinions such as:

It gives you same MPG but better accelerator.

or

I noticed no performance difference, but more MPG

or

It all depands if your car can make use of higher octane value fuels otherwise it's the same as your unleaded just wih a higher price (Think this was on shells website)

It's a myth that needs busting, can anyone help?

I've tried V-Power and haven't noticed any difference in power but thats me, but my polo has dropped alot in terms of performance for all sorts of reasons so it's really hard to tell, as for MPG I have not got a clue as when I filled it up we all went for a cruise and didn't pay any attention.

[Tim_GTi]

What car do you drive?

I've always used high octane fuel so unforunately cannot compare

[polo-sib]

I drive the MK4 Polo 1.0 (999cc injection model).

[Tim_GTi]

hhmmm well I've heard that high octane fuel is more effective with higher spec engines, but it's more refined than normal 95 ron so technically should be better for all engine types, whether or not the effects are worth it against the extra price though is another thing.

[adam_0612]

say i have a basically empty tank and i fill up with the better fuel would it matter if both types of petrol got mixed????

[Tim_GTi]

No not really, You wouldn't feel or get the proper advantages of high octane fuel though.

If you were to convert over fully it would take a good 2-3 tanks of high octane before it starts to take any effect