There are no cars that currently get 100 mpg, but there are a few that come close. The most fuel-efficient car on the market is the Toyota Prius, which has a combined city/highway MPG of 58. The Honda Insight and the Hyundai Ioniq also have very good fuel economy, with ratings of 55 and 54 MPG respectively. Of course, these figures will vary depending on your driving habits and the conditions you're driving in. But if you're looking for a car that's as fuel-efficient as possible, then one of these might be a good option for you.