[quote name='brensabre79' timestamp='1326217032' post='1493986']
Actually, there is a difference in petrol if you're running a performance engine. Supermarket brand petrol does cause a lot of sludge build up in the tank, its not really an issue unless you run low and then all the sludge goes through your engine. The more expensive brands put additives in the fuel to break the sludge down in the tank... I ran a performance car for a few years, thought nothing of filling up at Tesco every week, saved some money but not enough to pay the £4k bill for an engine rebuild. The mechanic (a friend) said don't ever take this car to the supermarket again! I didn't, I wrapped it around a tree a month later
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Agreed.
Companies buy in stocks and shares when it comes to fuel (or everything!). There are cheaper, crapper oil refineries and amazing, top notch ones. Supermarkets cut costs and go for the crapper one of the two to cut costs at their fuel stations to drag more punters in. They won't care about the implications about what happens to the vehicle as you have experienced.
In my opinion same goes for strings (and pretty much anything else) spend a little more money, get better quality products. I haven't changed my strings (DR Hi's on Spector and Rotosound PSDs on Ibanez) for a good year or so. They still sound amazing and my sweat is [b]very[/b] corrosive!