Before E10, we had E5 at 95 ron or 97/99 ron(super-unleaded) The 95 ron E5 has been removed from market in the uk, so essentially you can put in super-unleaded now or E10 which is my main issue, we should have the choice of 3 grade’s not just the two.
Most standard cars do not need higher octane 97/99 fuel and you will see no real difference running those cars on it than on the 95 ron. Some cars like a golf R will only run right on the 97 and above.
You will see a reduction in mpg over the E5 as it has more ethanol than before and thus less actual fuel but with the added cost of E5 being at least 5p to 8p per litre more than e10 and some supermarkets not even selling 95 ron, really imo it makes very little difference in terms of money.
Either way it’s costing more now than it did before to do the same mileage you could do on the e5 95 ron that’s no longer available.
A win win for the government and a lose lose for many people.