Question

How could the composition of gasoline be altered in areas with cold climates to aid in the starting of cars?

Answer 1

In cold climates, too little volatility of gasoline results in cars failing to start.

Therefore, in cold climates winter-blend gasoline is used.

The main its difference from an ordinary gasoline is that а litre of winter gasoline has less energy content than a litre of summer gasoline, typically in the range of 1.5-3%.