Top 10 Cheapest 40 MPG Cars

2. Toyota Prius c $19,875

It’s more than $5,000 cheaper than the normal Prius, and is about half-the size too. The miniscule Prius c subcompact is the first hybrid to come in below $20,000, and is good for 50 mpg combined on the EPA cycle. Don’t expect anything too crazy in the tiny Prius c. It uses the 1.5-liter four-cylinder engine from the Toyota Yaris, as well as an electric motor to make just under 100 hp combined. This is all paired to a CVT to help make the lightweight Prius c as fuel efficient as possible. See the full specs of the tiny Prius c right here.