Car services offer more options and you could even book a limousine if you wanted. There are plenty of cars or van types on offer and lots of companies to choose from so prices are hard to pin down but they will be more than a regular taxi if you are by yourself.
There are many car service companies operating from Heathrow Airport. You are able to book these cars in advance for a pickup at the airport and will be delivered directly to your hotel or home.
Hiring a van or larger car through any of the London car service companies can work out cheaper than a taxi because you can often fit more people and luggage and therefore split the cost.
Time: From 30 to 70 minutes depending on your destination and traffic.
Cost: Depends on the type of car hired.