I think the "cleaning properties " is mainly a marketing.
IMO driving styles has more to do with keeping the fuel system clean rather than if your using 91/95/98.
I recently have been working on a rio which has been exclusively run on BP 98 for all of its 90000KM, the throttle body was the dirties I have seen, took me a couple of hours to get clean.
I just stick with 91 and enjoy the on ramps
Interesting to take a look at MSDS for BP 91/95/98
95
3 . Composition/information on ingredients
Petrol 86290-81-5 >90
Contains:
Benzene 71-43-2 <1
tert-butyl alcohol 75-65-0 <1
tert-butyl methyl ether 1634-04-4 <1
Polycyclic aromatic hydrocarbons (PAHs) mixture <1
diisopropyl ether 108-20-3 <1
vs
91
Gasoline >90 86290-81-5
Contains:
Benzene <1 71-43-2
tert-butyl methyl ether(MTBE) <1 1634-04-4
2-methylpropan-2-ol <1 75-65-0
diisopropyl ether <1 108-20-3
Polycyclic aromatic hydrocarbons (PAHs) <1 mixture
and 98
3 . Composition/information on ingredients
Petrol 86290-81-5 >90
Contains:
Benzene 71-43-2 <1
tert-butyl alcohol 75-65-0 <1
tert-butyl methyl ether 1634-04-4 <1
Polycyclic aromatic hydrocarbons (PAHs) mixture <1
diisopropyl ether 108-20-3 <1
looks the same to me??