Originally, motorists drove cars without heaters or side windows, making winter driving very unpleasant. In addition, it was extremely difficult to start a car in cold weather. The eventual development of car heaters and side windows, and the improvement of engines and lubricants, led to more winter driving and the requirement of antifreeze/coolant. To prevent freezing and help cars run, early motorists used water with an additive such as honey, sugar, molasses and, the most popular, methyl alcohol. Despite good engine cooling ability, alcohol had the significant drawbacks of boil-away, odor, and flammability.