How accurate are manufacturers' charge range estimates?

A guide of the full-charge range for cars available in the UK, is between 150-350 miles.

Using high wattage applications in your car will use some of the electric charge.  For example, in the winter, your range will reduce when you're using your car heater etc.  However, running air conditioning in a petrol car can also use up to 10% more fuel.

Short journeys, uphill sections, hard acceleration and carrying lots of passengers, are all factors which will use more power.  So Billy-No-Mates driving calmly on the motorway in the Fens, will preserve a much greater part of their potential range compared with Speed Demon driving 4 mates round lots of local landmarks in the Highlands of Scotland!