One common concern for those who live in cities is whether or not constant idling and stop-and-start traffic can cause damage to a diesel engine. The long and short of it is that it makes little difference whether you're driving through New York, Paris, Rome, Berlin, or any other city. Your diesel engine will be fine if you follow the scheduled maintenance guidelines. In the UK, diesel engines are more common than petrol, largely due to the lower price-per-litre of diesel fuel. This is because diesel engines have a higher energy density and therefore produce more power from a given volume. In other words, a gallon of diesel will go further than a gallon of unleaded. This lower cost can sometimes make it difficult to justify replacing your engine for something newer, which would save you money in the long run. Diesel is bad for stop-start driving because it's difficult to get diesel to evaporate in cold weather. This means that if your car is idling for long periods of time, you will be using more fuel than necessary.