We get asked "What car should I buy?" fairly often. Once in a blue moon it's for a full-size sport-utility, but much more often it's for something smaller and more fuel-efficient.

And usually the word hybrid crops up pretty quickly. So we've gotten a lot of practice giving a little speech, which goes something like this:

The greenest car is the one whose engine runs the least. If you're doing lots of stop-and-go urban driving, a hybrid is perfect. But if you're driving 300 miles a week to visit family, other alternatives get mileage almost as good and cost a lot less.

Which brings us to the 2009 Toyota Yaris. It has Toyota's vaunted reliability and it offers three different body styles (3-door hatchback, 4-door sedan, 5-door hatchback).

Best of all, the manual-transmission version returns the highest fuel economy of any car sold in the US that isn't a hybrid, a diesel, or a Smart ForTwo. The EPA rates it at 29 mpg city / 36 mpg highway. And prices start below $13,000 for the most basic three-door.

As our colleague Bengt Halvorson reports, he got 41 miles per gallon on his standard mixed-usage 44-mile test route. That compares to 48 mpg on the same route in the outgoing model (2004-2009) Toyota Prius.

Like many subcompact cars with small engines (the Yaris sports a 1.5-liter four), hard acceleration generates lots of noise. And in a car that weighs less than 2,500 pounds, adding extra people does make a difference in how fast you take off from that stoplight.

Power windows and locks are optional, Bengt says, as is cruise control. There's no tachometer, but air conditioning is included.  He didn't much like the seat fabric--cheap and not that cheerful--but lauded the assembly quality and lack of rattles.

The 2009 Toyota Yaris isn't the only small car in the class, either. The well-reviewed 2009 Honda Fit, possibly the most versatile five-door hatchback on sale today, would be one of our favorite competitors.

Others to consider include the Chevrolet Aveo, the Kia Rio, the Hyundai Accent, and the Nissan Versa. All start well under $15,000 and return mileage in the high 20s or better.

Of course, if you're bound and determined to obtain 40 mpg or more for far less than $20,000 ... may we suggest a gently used Toyota Prius?

2009 Toyota Yaris 5-door

2009 Toyota Yaris 5-door