I find these arguments quite interesting as there are quite varied views from all members.
I dont think its fair to make a direct comparison in your spreadsheet between shell regular and V-power because as far as i know, V-power isnt just regular fuel with and 3-4 Ron on top which equates to extra miles per tank, you have to take into account of the detergents that are in V-power. If shell regular had these detergents as well, then yes, the spreadsheet comparison would be quite accurate.
I take a best of both worlds approach -i use 3 tank fulls of tesco momentum which is about £1.36 litre and 1 tank of v-power which is about £1.41 a litre.
This way, im exceeding the recommended minimum 98 Ron fuel as per instruction manual, saving a bit of money by using the momentum 99 Ron fuel but also benefiting from the detergents in V-power.
For members who use the 95 Ron stuff - There must be a reason why VW recommend 98 Ron fuel, they built the engines, have done all the years of R+D so must have a valid reason for recommending a minimum of 98 Ron fuel.
Im sure, the car
will run with tyres at 25PSI, cheap oil that doesnt meet the required VW spec, cheap brake fluid that does meet VW spec, cheap non oem coolant or cheap gearbox oil but it wont be running at it's best. Most people wouldnt dream of skimping on stuff as mentioned above but will skimp on the fuel
just my 2 pence
Rich