All gasoline-powered Mercedes-Benz vehicles, including the CLA, require unleaded, premium gasoline. Premium gasoline is any gas of at least 91 Octane. The CLA can use gasoline that contains up to 10 percent ethanol, called E10 fuel. It cannot use gasoline with any methanol content.
If CLA owners do not have premium fuel available, Mercedes-Benz vehicles can temporarily use lower octane fuel. However, owners should only fill the vehicles' fuel tank half-way, filling the remaining half with premium gasoline as soon as possible. Additionally, owners should not drive the cars at maximum speed, accelerate rapidly, or allow the engine to reach over 3,000 revolutions per minute.