No
In the USA, 1975.
Yes. You may not get the same performance (horsepower) as you would with premium gas, but modern cars can run fine on any grade of unleaded gas.
Yes you can. Super unleaded gas is just lower in lead so it will not leave as much residue in the system thus giving better gas mileage.
The best gas mileage from unleaded gasoline or premium gasoline depends on the car. Old cars get better mileage from unleaded.
In UK, all new cars from 1992 had to have a catalytic converter fitted, which required a strict diet of unleaded fuel. Many had 'cats' fitted as standard well before then.
According to the link below these four cars require premium unleaded fuel.
Most BMW Cars Take Unleaded Or For Some Special Ones Diesel.
all cars today run on unleaded gasoline. however older cars(60's -70's) some ran on leaded or unleaded. even so , some cars today cannot run on regular gas which has a lower octane rating. some need to run on premium gas , which has a higher octane rating.....
When I STOP AT A STATION i GOT UNLEADED GAS BUT FOUND OUT DIESEL GAS WAS MIXED IN WHAT WILL HAPPEN TO MY UNLEADED TRUCK
leaded gas has lead in it, unleaded does not Leaded petrol (or gas as you Americans quaintly call it) contained a chemical called Lead Tetraethyl to improve its performance. It was then discovered that the amount of lead given out by cars (or automobiles) was making city air dangerous to breathe and so its use has been forbidden. All petrol/gas is now unleaded and "green". Car engines have needed to be redesigned to allow them to burn the unleaded fuel.
There is no risk in mixing super unleaded gas and regular unleaded gas. Super is just given to the name of a gasoline because of cleaning agents and octane added to the gas not because the gas is completely different.