Stretching your fuel mileage saves time and money. Not only that, but it also limits your exposure to the inconveniences sometimes associated with filling up—grime-covered pump handles, bad coffee, congealed hot dogs, maybe even a bathroom key attached to the hubcap of a 1978 Ford Granada. Indeed, you and your car are at the mercy of wherever you happen to be when the fuel gauge needle hits empty.

The 6 after the jump…

Hybrid cars and trucks get plenty of attention for their miserly fuel economy. But there is more to a vehicle’s driving range than impressive mpg numbers. Fuel economy, curb weight, vehicle size, and the volume of the fuel tank all determine how far you’ll be able to travel between pit stops. Of course, a “compact” car doesn’t necessarily mean frugal. The 670-bhp Lamborghini Murciélago, for instance, is technically a compact, thanks to the dimensions of its cozy 2-passenger cockpit. But this supersonic Italian sports car has an estimated driving range of only 290 miles in combined city and highway driving. Put this $450,000 beauty in your garage, and you’ve bought a long-lasting friendship with your local gas station attendant.

Generally speaking, a smaller car has a smaller fuel tank. This disadvantage is usually offset by a smaller (i.e. more economical) engine. In the case of hybrids, a combination of an electric motor and gas-powered engine work together to boost range and mileage. But are hybrids the default choice when it comes to waving goodbye to frequent fill-ups? What are the options for car buyers who put a premium on driving range?

2011 Toyota Prius and 2011 Toyota Camry 4-cylinder
The 2011 Toyota Prius hybrid is the automotive darling of the green car world. Its unique styling and bevy of clever fuel-saving features make this midsize 5-door the benchmark for all other hybrids. Powered by a 1.8-liter 4-cylinder gasoline engine and an electric motor, the Prius offers a total of 134 bhp while returning fuel mileage of 51 mpg city/48 highway/50 combined. Based on the combined rating, expect to put about 595 miles on the odometer between each refill of the 11.9 gallon tank.

In comparison, a 2011 Toyota Camry powered by 2.5-liter 4-cylinder gasoline engine and 6-speed automatic transmission has a combined EPA rating of 26 mpg, which translates to a driving range of approximately 480 miles before the 18.5 gallon tank (6.6 gallons larger than the one in the Prius) runs dry. This gives the Prius a handy 115-mile range advantage over the most frugal Camry – and a point for a pro-hybrid crowd

2011 Honda CR-Z and 2011 Honda Civic Coupe
The 2011 Honda CR-Z is out to prove that hybrids can be as fun to drive as they are frugal to run. This sleek 2-passenger subcompact is powered by a 122-bhp 1.5-liter 4-cylinder gasoline engine coupled to an electric motor—the battery pack is located beneath the cargo floor. The CR-Z has sharp looks and nimble handling, much like its spiritual successor, the Honda CRX coupe. Straight-line speed isn’t earth-shattering but, all things considered, this is one very fun and economical little coupe.

Yet the tight packaging of the tiny CR-Z puts a crimp on driving range. A CR-Z equipped with a CVT automatic transmission returns an official EPA fuel economy rating of 31 mpg city/37 highway. With its 10.6 gallon tank (and an EPA combined rating of 37 mpg), the CR-Z manages 392 miles between fuel stops. That’s only 9 miles better than the 383-mile range you’ll manage in a 2011 Honda Civic Coupe in DX trim, which has an EPA combined rating of 29 mpg and a 13.2-gal. fuel tank. Motivated by a 140-bhp 1.8-liter 4-cylinder gas-powered engine with a 5-speed automatic, the Civic has room for two additional passengers and, in lower trim levels, costs significantly less than the $19,950 base price of the CR-Z.

2011 Audi A3 TDI and 2011 Audi Q7 TDI
In the world of diesels, size matters when it comes to driving range—although not in the way you might expect. Take the 2011 Audi A3 TDI, a handsome compact 5-door hatchback with a 140-bhp 2.0-liter 4-cylinder turbodiesel engine under the hood and a smooth-shifting 6-speed automatic transmission that makes excellent use of the available power. The front-wheel-drive A3 TDI is a genuine delight to drive on a winding road. Its economy also makes it the scourge of gas station franchisees. The A3 TDI offers fuel economy of 30 mpg city/42 highway, with a combined rating of 34 mpg. This is especially handy since filling up with diesel isn’t always the most sanitary experience—wash your hands afterwards or you might smell like a tanker truck.

Even more impressive is the A3 TDI’s combined driving range of 496 miles, thanks in part to a 14.6-gal. fuel tank. This range can stretch upward of 600 miles if most of your motoring is done on the highway. Sounds great, except the A3 TDI has a big brother that manages an even more impressive bladder-bursting driving range. The 2011 Audi Q7 TDI doesn’t come cheap; with a base price of $51,775 it costs roughly $20,000 more than an A3 TDI. You’ll also get more power, luxury, cabin space and Audi’s signature Quattro all-wheel-drive system. The EPA fuel economy of 17 mpg city/25 highway (20 combined) may not be all that impressive, until you couple it with the Q7’s mammoth 26.4-gal. tank. This makes for a combined driving range of 528 miles…or a whopping 660 miles of all-highway driving.