Figure 3: Delta-V vs Fuel Requirements

Delta-V vs Fuel for most rockets

All this business with delta-v means that we are talking about a lot more fuel than a car might take. In fact, a car would only be useful if the delta-v was below 1 km/s. It is pretty obvious that most trips in space are going to require a big fuel tank. Not all trips, just most. Typical trips are listed along the lower bound. So somewhere between 50-90 percent fuel is required to get anywhere past LEO (and it takes roughly 90 percent fuel to get to LEO in the first place). This makes it obvious why not many people have been sent into space. Click the image for a larger version.