well without opening an old can of worms.... yes bp ultimate is rated at 97 ron (also more expensive v-power)... where as the likes of shell v-power and tesco's t99 are both 99 ron rated... i personally only use v power as i have a shell like 2 miles from my house.... if i had a choice i would use tescos t99... company downsouth who do alota modifying from bmw's to vx220 to zafira's, "thorney motorsports" did a long term fuel test and they recommend tescos t99.. the vx220 boys will know the company very well and so will vxr boys... they occasionally appear on top gear aswell.. ie the bmw britcar and the renault avantime.. thorney motorsport crew...
-ho