Supermarket fuel v the rest

Jackmydad

Rover_Driver wrote: »

I agree that some claims may be optimistic, but there are still those who won't accept that some people have found an improvement, and are convinced there is no difference between using supermarket and branded fuel.

I'll accept that some people subjectively think that there is an improvement.
As I said before, I think that my car drives better when I've washed it. However when I look at it objectively I can see no logical reason at all why it should make it any better. So it must be that I "feel" better about it.
I think that the fuel thing is much the same.
If you bring me the figures off a rolling road to prove that your car is producing more bhp on a given fuel, for a given throttle setting, then I'll believe that. Figures from a vibration testing rig to say it's smoother for a given load? Great! no argument.
Otherwise as Joe Horner says above there are just too many variables.

AdrianC

I'd be happy with the results of genuinely double-blind trials.

Jackmydad

AdrianC wrote: »

I'd be happy with the results of genuinely double-blind trials.

Yes that would do it as well with a lot less trouble.
I'm pretty sure that it'd show no significant difference though.

Joe_Horner

Jackmydad wrote: »

As I said before, I think that my car drives better when I've washed it. However when I look at it objectively I can see no logical reason at all why it should make it any better.

Well, obviously, the layer of dirt affects the surface finish and increases wind resistance, plus alters the weight distribution because most of the dirt tends to accumulate around the back.

Many drivers who just use cars A to B probably wouldn't notice the difference but a true enthusiast like yourself .... :beer:

Jackmydad

Joe_Horner wrote: »

Well, obviously, the layer of dirt affects the surface finish and increases wind resistance, plus alters the weight distribution because most of the dirt tends to accumulate around the back.

Many drivers who just use cars A to B probably wouldn't notice the difference but a true enthusiast like yourself .... :beer:

:rotfl:
Of course a really good wax helps too!
A true enthusiast like me who drives an eight year old Peugeot, and doesn't clean the car very often!

motorguy

IanMSpencer wrote: »

Some of that can be down to the electronic ignition and the design of the engine. Some petrol engines are designed to run on premium fuel but can run on anything, others are optimised for the basic fuel and aren't going to achieve much.

Also, you need to consider whether you are really comparing apples and pears - often people seem to discuss comparing supermarket fuel with a branded premium fuel, not a branded basic fuel. I'd say a base fuel from a brand isn't going to be much different from supermarket fuel (and often isn't priced much different depending on location either to be fair).

This thread was specifically started about diesel fuel though.

Also dont confuse "premium" petrol with high octane petrol.

trailingspouse

Well, I filled his car with ordinary branded diesel yesterday. Not supermarket diesel, but not premium diesel either. Baby steps.

Will see if he notices...

ohreally

If diesel, I'd use a branded fuel rather than supermarket during the winter months. I understand a higher % of biodiesel is used in supermarket diesel.

zagubov

Don't know about diesel, but petrol formulations change throughout the year to cope with seasonal temperatures.

I always use supermarket petrol stations and when using motorways use those websites that show where the nearest cheap supermarket petrol is.

motorguy

zagubov wrote: »

Don't know about diesel, but petrol formulations change throughout the year to cope with seasonal temperatures.

I always use supermarket petrol stations and when using motorways use those websites that show where the nearest cheap supermarket petrol is.

Yes theres winter diesel and summer diesel.