I always use RON98 for my '74 450SEL. But I'm beginning to understand that that is not a guarantee for good gasoline.
I was on a long trip with my wife and kids from Sweden to Germany via Danmark. Somewhere on the way back I had to fill up with gas. Now today it is not so easy anymore to find RON98 at gas stations in Northern Europe.
I got a tip from a pedestrian to find a SHELL station some kilometers off the highway.
There I found they had SHELL V power which is RON99 and especially developed for (modern) high performance cars. It is said that this is the only gasoline which is transported to gas stations 'as is'. I mean they don't mix the stuff with additives at the station which is probably normal then for the other types of gas.
I know they mixture with additives like ethanol and white spirit in normal gasoline depending on winter or summer weather.
Now I'm generally not impressed by -in this case Shell's- marketing drive for SHELL V-power. That means that I tend to be suspicious to marketing tricks.
Normally I get 600km out of a tank and then I fill it up with 80-83 litres when I drive steady highway speeds of 110-120km/h. Now with SHELL V-power I'm already over 600km's and I have not been driving on the highway alone! The reserve light is still not on! (and it isn't broke, because it worked when I drove down the steep slope into the garage
Of course Vpower is even more expensive as RON98 but when I fill up the tank next time I will report the economical calculations and get back to this thread.
An other thought came up to me and that is that when I park the car for the winter, the best thing is to fill it up with gasoline. Gasoline deteriorates a little bit has been said over here. Well, even if SHELL V power is not economically justified it is probably a very 'clean' gasoline and it would maybe be a good idea to empty your tank of average RON98 and fill it up with 20 litres of Vpower that can sit there 'till next spring?
(this is not a disguised commercial, I just wanted to let you people know about my experiences... )