Most Economical Car

Here you'll find the most efficient cars for each different class of vehicle.

We've listed the fuel consumption data by country since each has its own set of testing procedures.

Go ahead and select a country:

Before the 1990's economical cars typically used a small gasoline or petrol engine. Up until this point alternative engine technology was not yet advanced enough.

During the 1990's efficient diesel engines became increasingly popular due to the introduction of diesel turbo-chargers and direct injection. Diesel technology has continued to improve over the last two decades and today is a highly efficient, very refined power source.

Around the year 2000, hybrid cars consisting of both an internal combustion engine and an electric motor began to appear.

Pure electric vehicles are now starting to gain momentum due to a vast improvement in battery technology over the last decade.

When building the most economical car with a gasoline (petrol) engine its vital to keep the engine capacity down. Often only 3 in-line cylinders are used instead of the usual 4 cylinders. Cylinder deactivation can be used on larger 6 or 8 cylinder cars to shut down cylinders when they're not needed.

Direct fuel injection into the cylinders of gasoline engines allows for a more efficient fuel intake which results in lower fuel consumption.

Variable valve timing is another aid to fuel economy. The optimum valve timing setting depends on the engine speed, so having a system that can change the timings on the fly increases efficiency.

Diesel engines are very popular in Europe and you'll find the most economical car tables for the U.K. are full of them. By contrast they are not widely used to power cars in the U.S. although this is changing.

We're seeing much smaller diesel engines now which are suitable for economical small cars. Turbochargers are fans which force extra air into the cylinders and they allow manufacturers to get the same performance from smaller engines.

Common rail diesel systems use an engine driven pump that produces extremely high injection pressures. The high pressure results in a more complete burn, more power and greater fuel efficiency.

The hybrid approach to building the most economical car is all about reducing the City MPG figure as much as possible. The city is where the hybrid technology works best. Out on the open road its largely negated.

Stop/start systems for a hybrid car's gasoline engine helps to save fuel by switching it off when stationary. Hybrids that offer all-electric modes boast even greater fuel savings since the gasoline (petrol) engine does not need to run at all until a certain speed is reached.

Regenerative braking converts the the hybrid car's kinetic energy into electric energy to be stored in batteries. Traditional brakes dissipate the energy as heat.

Electric motors are about 90% efficient at converting the energy stored in batteries to mechanical energy to drive the wheels. By comparison an economical gasoline (petrol) internal combustion engine is roughly 25% efficient and a modern economical diesel engine is in the range of 40-45% efficient.

The reason electric motors are so much more efficient is because they only suffer energy loss in the form of heat. By contrast internal combustion engines have far greater heat energy losses and in addition also suffer energy loss in the form of engine friction, sound, and through running pumps and generators necessary for the engine to operate.