Supermarket petrol

[Kss47]

I have a one year old Polo 1.2TSI Match edition. Apart from when I've made a long journey and had to fill my car with petrol at whatever service station was most convenient I've been using Shell petrol (standard petrol, not V power) and the car's been fine. However as I was low on fuel the last time I filled up with petrol I did it at nearby Asda. Since then the engine hasn't been as smooth especially when cold. So it's back to Shell for me, has anyone else had a problem with supermarket petrol. My last car was a Polo 1.4TDI and I had no problems with Asda diesel.

[SRGTD]

I’ve never used Asda fuel but I regularly fill up at Tesco and haven’t ever had any issues with their fuel; petrol or diesel (my previous car was a diesel).

[joe6]

A supermarket filling station, will define a minimum performance level required from the fuel (probably related to cost?), which results in different levels and types of additives added to the ‘base’ fuel. The 'base' fuel is made to a british standard and is the same whatever the brand. The difference between brands is the additives used which can affect the MPG and general running of the vehicle and in some vehicles is more extreme than others. In some cases you may not notice any difference at all. I too like Shell (it may be the advertising hype?) but if 'caught short' I try to use Tesco momentum 99 rather than the 'standard' stuff as it is clear what performance level it provides.

[SRGTD]

It’s Momentum 99 I get when I buy petrol from Tesco.

[Kss47]

Thanks for your replies. I don't do much mileage these days so the extra cost of Shell over Asda petrol doesn't amount to too much over the year. The only issue being that the Shell garage is some 5 miles or so away and not so convenient. As I go to Tesco each week it I might try their Momentum 99.

[RUM4MO]

Currently I refuel my wife's 1.2TSI 110PS Polo 6C using Costco ordinary grade on petrol, initially I filled at Esso, but now that Costco have opened their fuelling station I tend to use it at either every other fill or maybe 1 out of 3 fills. So far I've not noticed any issues while running the Costco fuel.

Though as said earlier, all the "base" spirit, which is not what the modern engines like to devour by itself, are the same locally - but the fuel is made suitable for modern engines by the additives - and these vary from brand to brand, and I'd guess that the supermarket additives are "lesser" than the quality brands, and maybe the control of where and when they are added is less well enforced by the supermarket suppliers.