Brits also think our gasoline is crappier because we use a different calculation for octane, (R+M)/2 instead of RON.
So 90 RON is actually 85.9 in the US. And in most of the country the minimum is 87 (R+M)/2.
93 Premium is like 98 RON. And race gas 100 is like 105 RON.
To be fair though, your petrol is still insanely cheap compared to the UK and Europe.