If you are in the market for a new car, opting for a Mercedes will certainly offer you many great attributes such as comfort, style and performance. But, if your primary goal is fuel efficiency, Mercedes also has many efficient cars to choose from.
If you want a regular gas-powered non-hybrid model, the most efficient new Mercedes sedan is the C300, which can return an impressive 28MPG US combined highway/city driving. If you are mostly interested in smaller SUVs, the GLA 250 will offer you the same MPG US results.
But the most fuel-efficient Mercedes model on sale is the Mercedes-Benz E 300 BlueTEC HYBRID, which is able to return an astonishing 69MPG US. This model is not only the most efficient Mercedes model, but it’s also a class leader in the mid-size sedan segment.
Most fuel-efficient Mercedes SUVs
If you only care about SUVs, Mercedes has a couple of models that also offer class-leading efficiency results.
The most efficient smaller SUV by Mercedes is the 2020 Mercedes Benz GLC350e 4-Matic, a small SUV powered by a 2.0 liter 4-cylinder gas engine combined with an electric motor that is able to return as much as 66MPG US, realistically. This model starts at around $52k and it offers 315hp and an impressive 0-60 time of 5.6 seconds.
If you want a good family gas-powered SUV, the GLB250 also offers great fuel efficiency at around 27MPG US. The GLB250 and the GLA250 are both powered by the same 2.0 liter 4-cylinder engine with around 220hp, and both can be acquired at around the $35-40k mark.
However, if you want a larger SUV, the regular gas-powered Mercedes GLE 350 4-Matic is good for about 22MPG US, which is not a bad result for a large SUV. The hybrid version of the GLE is able to return a fairly impressive 58MPG US.
Most fuel-efficient Mercedes sedans
The most fuel-efficient gas-powered small Mercedes sedan is the aforementioned C300. This variant of the C-class uses the 2.0 liter 4-cylinder engine that many Mercedes Benz models on this list use. The 28MPG US is rather impressive, but so is the 255 horsepower and the 9-speed automatic transmission.
When it comes to the popular E-class sedans, the E350 4-Matic is able to return a fairly commendable 26MPG US. The E-class uses a similar engine to the aforementioned C300, which means that the power output is also the same. Also worth mentioning, is that both the C-class and the E-class have the same sized fuel tank, so you are able to go a little bit further in the C300.
If you want an even more efficient Mercedes sedan, the E300 BlueTEC gas/electric powered hybrid version returns the best fuel economy in the Mercedes sedan range. This E-class is powered by a 2.0 liter 4-cylinder engine plus an electric motor that pushes out an impressive 316 horsepower combined.
The average real-life usage scenario should give you around 69MPG, but even better fuel economy can be achieved, depending on the way the car is used and the conditions under which it operates.
Ways of increasing your fuel efficiency
These numbers only tell half of the story though, as they are mostly dependent on specific usage scenarios that cannot be replicated entirely. The MPG results are shown here as an average, and should only pose as a waypoint of what is to be expected, and not a given MPG result.
Nowadays, car manufacturers use every available trick to increase the MPG results, so a manufacturer-claimed MPG is almost always way out of reach, but the way you drive your car can affect the fuel efficiency quite a lot.
Aerodynamics plays a huge role in fuel efficiency. It is to be expected that a vehicle traveling at a constant high speed with a roof cargo box would be less efficient on fuel by as much as 20%. Traveling with your windows opened at a high-speed also greatly affects your MPG results.
Reducing the weight of your car can also do a lot for your fuel efficiency. The same can be said about driving your car in a lower gear, or a higher RPM. Furthermore, automatic gearboxes use 10-15% more fuel, and the AC and improper maintenance of your vehicle can also worsen the MPG results quite a bit.
Gas vs Diesel vs Electric
Are diesel-powered cars more fuel-efficient than gas-powered cars?
It is expected for a diesel to use 15-20% less fuel which in turn should mean that the running costs are more affordable. But the taxes for newer diesel-powered cars are a touch higher than they are for a gas-powered car, so they might bring the margin a bit closer.
Diesel cars are also way more efficient when it comes to constant high-speed driving such as on highways. They also offer more low-down torque so they use less fuel when passing other vehicles. On the other hand, gas-powered cars usually offer better fuel efficiency in a city driving environment.
Are diesel-powered cars able to last longer than a gas-powered car?
Diesel cars are usually more capable of reaching higher mileage results, and they are pricier on the second-hand market, but servicing a diesel engine is more expensive than it is to service a gas engine.
In the older days, many Mercedes diesel engines were able to last hundreds of thousands of miles without the need for major overhauls, which cannot be said about their gas counterparts. But nowadays the margin should not be as pronounced as it once was.
Should I buy an electric car for better efficiency?
Buying an electric car certainly does make your driving more efficient and less harmful to the environment. However, most places in the world, even the developed ones, do not have the proper infrastructure to make it as convenient as it is to own a combustion engine.
The best of both worlds is to choose a hybrid from a developed brand that is surely not going to suffer from reliability. Owning a hybrid is also not as convenient as it is owning a combustion engine car, but the benefits like lower running costs and lower tax shouldn’t be forgotten.