How can a hybrid car achieve 50 mpg?

Scott Benjamin

By now you've probably hard the news that the third-generation Toyota Prius, better known as the 2010 Toyota Prius, will be the most fuel-efficient vehicle you can buy in the United States when it hits the market this June. How fuel efficient? Well, with a combined (city/highway) EPA estimated fuel economy rating of 50 miles per gallon, the 2010 Prius is well ahead of the ever-growing hybrid car competition at this point. There simply aren't any other hybrid cars available that have reached the 50 mpg threshold...not yet, anyway.

However, being on top in the hybrid car segment isn't exactly new to Toyota. In fact, according to fueleconomy.gov, the 2009 Toyota Prius is listed as the current model year's most efficient EPA certified vehicle achieving 48 mpg in the city, 45 miles per gallon on the highway for a combined mileage average of 46 miles per gallon. So, how did Toyota further refine this already fuel-efficient sedan?

Actually, that's the answer -- a significant amount of refinement. There was no all-new, complete redesign of the Prius and no radical new super-secret technology that Toyota engineers just discovered...the designers and engineers at Toyota simply further developed what they were already doing right. For instance, refining the vehicle's aerodynamics giving the 2010 Prius sharper corners (while maintaining the "dynamic triangle" form) not only improves the vehicle's appearance, but also reduces the coefficient of drag (Cd) to a slippery 0.25 compared to the second-generation Prius that had a 0.26 Cd. It doesn't sound like much, but it makes a big difference at highway speeds. Of course, there are a few new technologies at work here and there throughout the car, too, and those are included for efficiency and durability.

One point that I need to clarify is that the hybrid powertrain within the Toyota Prius is the primary reason this car gets such great fuel mileage. But the real key to the Prius' success is how that fuel-efficient mechanical and electrical system works in concert with the rest of the car's features.

Now, this isn't a complete list by any means, but it will give you a fairly good idea of some of the efficient components and systems that the 2010 Toyota Prius takes advantage of on its way to 50 miles per gallon:

2010 Toyota Prius

More fuel-efficient stuff: HowStuffWorks - Auto Fuel Economy Channel How Hybrid Cars Work How Aerodynamics Work 2010 Toyota Prius Review and Prices