The last post was about power to weight ratio. We will now talk about engine tuning and horsepower per liter.

Horsepower per Liter Comparison of a V6 and 4-Cylinder Engine

Horsepower per liter is only a small factor in determining performance. However, car manufacturers are putting more emphasis towards efficiency rather than pure pulling power. Remember that your car may have the biggest horsepower per liter figure among other comparable vehicles but this does not mean that your car is the fastest nor the most efficient.

Engine builders make sure to tune the engine towards achieving maximum power and torque with acceptable levels of fuel efficiency. Add to that the emissions factor of the engine and what you get is a tight balancing act between the three factors:

1. Power

2. Economy

3. Emissions

Let us again take the 2012 Hyundai Sonata SE 2.0T as an example. With a turbocharged and intercooled 2.0-liter 4-cylinder engine, the Sonata can achieve 274hp at 6,000RPM and reach 22mpg in the city and 33mpg on the highway.

This magnificent power plant produces a horsepower per liter rating of 137. This can be calculated as follows:

264 horsepower / 2.0-liters = 137.

The figure is higher than other comparable cars with larger V6 engines such as the Toyota Camry V6 and the Honda Accord V6. Truth be told, the Honda Accord’s V6, with 3.0-liters of displacement and an output of 271hp is only rated at around 90 horsepower per liter. Toe to toe, the Sonata’s engine is more powerful and more efficient. It burns cleaner, too. Even the Chevy Malibu, Nissan Altima and the Ford Fusion–all with V6 engines–pale in comparison to the horsepower per liter rating of the Hyundai Sonata.

Is this enough reason why you need to choose a 4-cylinder engine over a V6? Is the cost alone enough to justify the logic?

This will all depend on your driving habits and driving needs. City dwellers and urban yuppies will do better with a 4-cylinder engine. Why will you need the added oomph of a V6 if you are constantly crawling in city traffic day-in and day-out?

The point remains clear: as long as the car is not burdened by excess weight, a 4-cylinder engine will always be more economical to run than a V6. It is also cheaper to maintain. If you want an economical family car then a car with a 4-cylinder engine is more than enough for your needs.

Keep all this in mind before purchasing a new car and you are sure to get your money’s worth if you choose wisely. Remember that buying a new car is an investment. It need not be gamble.