Four-Cylinder vs. V6 and V8:
In most cases, the smaller the engine, the better the fuel economy. This means that instead of buying a car with a V6 or V8 engine, consider getting the four-cylinder engine for that car. The initial purchase price will be lower and you will save money on gas. Many four-cylinder engines, particularly those that are turbocharged, are surprisingly energetic and can provide plenty of power for merging and passing.
Standard vs. Automatic Transmission:
When it comes to smaller, compact-size cars, a manual transmission comes standard; getting an automatic transmission sometimes adds about $800-$1,000 to the purchase price. Meanwhile, a manual-shift typically achieves slightly better gas mileage and also allows you to drive in a more fuel-efficient way. If you don't live in the city and don't get stuck in traffic a lot, this is a money-saving alternative for you. You might also consider the new breed of automated manual transmissions, which combine the fuel efficiency of a manual with the ease of a traditional automatic, though with a slight loss in the refinement that a traditional automatic offers. If an automatic is what you need, consider one that offers a broad spread of gear ratios; six-speed automatics are relatively common now and eight-speed automatics are offered on some luxury models.