I used asda 95 octane for a year or so before I joined this forum and learnt the error of my ways. The car should run fine on 95 as the engine compensates but it's not the recommended fuel to use. When I switched to v power the mpg improved by 2, which I calculated was about the same as the extra cost - so £ per mile was the same. If you're going to put premium fuel in then v power or tesco is best as they are 99ron, BP is only 97ron (hence why you've seen it's cheaper).