This page collects every fuel-economy figure the EPA publishes for the 2020 Mercedes-Benz CLS450. Below you will find the headline combined, city, and highway MPG, the estimated annual fuel cost at three different driving levels, the tailpipe CO₂ emissions, and a full breakdown of the engine and drivetrain. If you want to know whether this generation got more or less efficient over the years, the year-over-year table further down covers every model year the EPA has rated.

Key takeaways

  • The most efficient car in the Compact Cars class for the 2020 model year is the Toyota Corolla Hybrid at 52 MPG.
  • EPA estimates this car costs around $2,500 more in fuel over five years than an average new vehicle of the same model year.
  • Requires premium gasoline, which typically adds about 40 to 60 cents per gallon to the EPA's annual fuel cost estimate.

Fuel economy at a glance

These are the EPA's official ratings for the 2020 Mercedes-Benz CLS450. The numbers come from a standardised laboratory test cycle and are the same figures that appear on the window sticker of every new car. Real-world mileage varies with driving style, weather, fuel quality, and how heavily loaded the car is.

Combined MPG is a 55/45 weighted blend of the city and highway test cycles. The EPA uses it as the single number you can compare across the entire dataset, including hybrids and EVs (which use the equivalent MPGe figure).

Combined MPG 26 MPG
City MPG 24 MPG
Highway MPG 31 MPG
Annual fuel cost $2,650
Tailpipe CO₂ 334 g/mi
Fuel type Premium

How the 2020 Mercedes-Benz CLS450 compares

The 2020 Mercedes-Benz CLS450 returns 26 combined MPG. Cars in the Compact Cars class for the same model year average 26.9 MPG, which puts this car behind the class average by about 3%.

The most efficient car in the Compact Cars class for the 2020 model year is the Toyota Corolla Hybrid at 52 MPG. The bar chart below puts the Mercedes-Benz CLS450 alongside the class best and the class average so you can see the full picture.

For broader context, the average new car of the 2020 model year (across all classes) returns 27.2 MPG. Larger vehicles pull the all-cars average down, so do not use that figure on its own to judge a small car or a hybrid. The full list of the most efficient cars of the 2020 model year is on its own page.

2020 Mercedes-Benz CLS450
26 MPG
Class average, 2020
26.9 MPG
Class best, 2020
52 MPG
Average new car, 2020
27.2 MPG

Annual fuel cost across driving patterns

The headline annual fuel cost the EPA publishes assumes 15,000 miles of driving per year and a fuel mix of 55% city and 45% highway. The dollar figure is calculated using the EPA's current reference price for premium gasoline, which is $4.61/gallon. EPA updates that reference periodically rather than tracking live pump prices, so treat it as a window-sticker estimate rather than today's pump number.

The table below scales the EPA's number to three common driving patterns. The combined MPG and the reference fuel price stay constant, only the annual mileage changes. To get a current-prices estimate, take your local gas price and multiply by 576.9 gallons (the car's annual consumption at the rated MPG).

Driving pattern Estimated annual fuel cost
Light driver, 7,500 miles per year $1,325
Average driver, 15,000 miles per year $2,650
Heavy driver, 25,000 miles per year $4,417

Year-over-year MPG for the Mercedes-Benz CLS450

The EPA has rated the Mercedes-Benz CLS450 across 3 model years, from 2019 Mercedes-Benz CLS450 through 2021 Mercedes-Benz CLS450. The numbers below are the best combined MPG figure the EPA published for each year, which lets you see when the car was at its most efficient and how recent generations stack up.

Combined MPG has stayed in roughly the same range across the run, hovering close to 26 MPG.

Year Combined MPG Open year page
2021 26 MPG 2021 Mercedes-Benz CLS450
2020 26 MPG this page
2019 26 MPG 2019 Mercedes-Benz CLS450

Compare against other Compact Cars for 2020

If you are cross-shopping the 2020 Mercedes-Benz CLS450, the most useful comparison is against the other cars in the Compact Cars class for the same model year. The list below shows the highest-MPG peers, ranked from most to least efficient. Click any of them to open its full page.

The Toyota Corolla Hybrid leads this group at 52 MPG, 26 MPG ahead of the 2020 Mercedes-Benz CLS450.

Specifications

The 2020 Mercedes-Benz CLS450 runs a 3-liter 6-cylinder turbocharged engine paired with a automatic 9-spd, sending power through rear-wheel drive.

Engine, transmission, and drivetrain together drive most of the variation in fuel economy across trims. A larger engine moves the car with less effort but burns more fuel. A turbo lets a small engine punch above its weight, often without much MPG penalty. All-wheel drive adds traction and weight, and usually costs a couple of MPG compared with two-wheel drive of the same engine.

Vehicle class
Compact Cars
Engine
3L 6-cylinder turbocharged
Transmission
Automatic 9-spd
Drivetrain
Rear-Wheel Drive
Fuel type
Premium
Annual petroleum use
11.4 barrels per year
Start-stop system
Yes

Common questions about the 2020 Mercedes-Benz CLS450

Quick answers to the questions people most often search for when looking up the 2020 Mercedes-Benz CLS450.

  • Is the 2020 Mercedes-Benz CLS450 fuel efficient?
    It is in line with the rest of the class. The 2020 Mercedes-Benz CLS450 returns 26 combined MPG, and the average car in the Compact Cars class for the same model year sits at 26.9 MPG.
  • What MPG does the 2020 Mercedes-Benz CLS450 get?
    The EPA rates the 2020 Mercedes-Benz CLS450 at 26 combined MPG, 24 MPG in city driving, and 31 MPG on the highway. Real-world numbers depend on your driving style, the weather, and how loaded the car is.
  • How much does it cost to fuel a 2020 Mercedes-Benz CLS450 per year?
    The EPA estimates an annual fuel cost of $2,650 for the 2020 Mercedes-Benz CLS450. That figure assumes 15,000 miles of driving per year, a 55% city and 45% highway split, and the EPA's published average fuel price for the rated fuel grade.
  • Does the 2020 Mercedes-Benz CLS450 require premium gas?
    Yes. The EPA lists the 2020 Mercedes-Benz CLS450 as requiring premium gasoline. Running it on regular can reduce performance and may affect engine warranties, so it is not a recommended way to save at the pump.
  • Has the Mercedes-Benz CLS450 become more fuel efficient over time?
    Combined MPG has stayed close to flat across the run. Both the earliest (2019 Mercedes-Benz CLS450, 26 MPG) and most recent (2021 Mercedes-Benz CLS450, 26 MPG) versions sit in the same range.
  • How much CO₂ does the 2020 Mercedes-Benz CLS450 emit?
    Tailpipe CO₂ emissions are 334 g/mi. Multiplied across a typical year of driving (15,000 miles) that works out to about 5,010 kilograms of CO₂.
  • What is the difference between the city and highway MPG of the 2020 Mercedes-Benz CLS450?
    City driving returns 24 MPG and highway driving returns 31 MPG, a gap of 7 MPG. A spread that wide is typical of cars with conventional automatic or manual transmissions, where stop-start city traffic eats more fuel than a steady highway cruise.
  • What engine is in the 2020 Mercedes-Benz CLS450?
    The 2020 Mercedes-Benz CLS450 has a 3-liter 6-cylinder turbocharged engine (EPA description: SIDI; Mild Hybrid).
  • What transmission and drivetrain does the 2020 Mercedes-Benz CLS450 have?
    The 2020 Mercedes-Benz CLS450 comes with a automatic 9-spd transmission and rear-wheel drive.
  • How does the 2020 Mercedes-Benz CLS450 compare to the best car in its class?
    The most efficient car in the Compact Cars class for the 2020 model year is the Toyota Corolla Hybrid at 52 combined MPG. The Mercedes-Benz CLS450 returns 26 MPG, a gap of 26 MPG. If you are comparing on fuel economy alone, the class leader is worth a look.

Source: U.S. EPA fuel economy dataset. Annual fuel cost figures assume 15,000 miles of driving per year and a 55% city, 45% highway split. Real-world mileage varies with driving conditions, vehicle maintenance, fuel quality, and driver behaviour.