Mercedes A-Class Owners' Guide

Since its introduction in 1997, the Mercedes A-Class has evolved from a compact city car into a sophisticated, premium hatchback widely lauded as one of the best all-round family cars.  

This owners’ guide compiles key information about your A-Class in one convenient place, covering service intervals, recommended tyre pressures, and answers to frequently asked questions to help you keep your car running smoothly. 

Mercedes A-Class generations

Mercedes A-Class 1997-2004 

The first A-Class represented a radical departure from Mercedes-Benz tradition because it was the brand’s first foray into the compact segment. It had a tall, upright design with a unique ‘sandwich floor’ construction, which put key components like the engine and gearbox between two steel floors in the passenger compartment, for crash safety.   

The Mk1 A-Class was hit by criticism of its handling, notably after it toppled over during the infamous ‘Elk Test’. This failure led to the introduction of electronic stability control (ESC) as standard. 

Body styles: 

• Five-door hatchback 

Key engine options: 

• 1.4-litre 82bhp petrol 

• 1.6-litre 102bhp petrol 

• 1.9-litre 125bhp petrol 

• 1.7-litre 75bhp diesel 

Mercedes A-Class 2004-2012 

The second-generation model refined the original formula with improved quality and a more conventional appearance. New technologies were introduced, including a sat-nav, active damping, and a CVT automatic gearbox.   

A facelift in 2009 introduced start-stop technology, resulting in a fuel saving of 9% during city driving. Mercedes also introduced an Active Park Assist function. 

Body styles: 

• Three-door hatchback 

• Five-door hatchback 

Key engine options: 

• 1.5-litre 95bhp petrol 

• 1.7-litre 117bhp petrol 

• 2.0 193bhp turbo petrol 

• 2.0-litre 82bhp diesel 

• 2.0-litre 140bhp diesel 

Mercedes A-Class 2012-2018 

The 2012 A-Class underwent a complete transformation into a sporty hatchback aimed at younger buyers. It had a new dynamic design, significantly upgraded tech, and a sharper driving experience – all of which helped to establish it as a serious contender in the premium hatchback segment, capable of competing with established rivals like the BMW 1 Series and Audi A1. 

All third-generation A-Class models came with a Collision Prevention Assist system that monitors the road ahead and alerts the driver if it senses an imminent impact.  

Body styles: 

• Five-door hatchback 

Key engine options: 

• 1.6-litre 122bhp petrol 

• 2.0-litre 211bhp petrol 

• 2.0-litre 381bhp turbo petrol 

• 1.5-litre 109bhp diesel 

• 2.1-litre 170bhp diesel 

Mercedes A Class 2018-present 

The upmarket interior of the fourth generation A-Class is dominated by the MBUX infotainment system, which uses twin screens (one behind the steering wheel with digital instruments and driving information; one in the middle of the dash with the usual infotainment functions) in one unit.  

Standard equipment includes cruise control, alloy wheels and keyless entry. A facelift in 2023 brought a new front grille design, new front and rear bumpers, and subtle tweaks to the trim and paint options.   

Body styles: 

• Five-door hatchback 

• Four-door saloon 

Key engine options: 

• 1.3-litre 136bhp petrol 

• 2.0-litre 224bhp petrol 

• 2.0-litre 218bhp petrol plug-in hybrid 

• 2.0-litre 306bhp turbo petrol 

• 1.5-litre 116bhp diesel 

• 2.0-litre 190bhp diesel 

Service intervals

Maintaining your A-Class is crucial to minimise breakdowns and extend its lifespan.   

Mercedes service intervals are typically divided into two main categories: A and B. 

Service A 

Service A is carried out every 10,000 miles or 12 months, whichever comes first. It focuses on basic maintenance, including: 

• Oil and filter change 

• Fluid level checks 

• Tyre rotations 

• Brake component inspection 

Service B 

Service B is performed approximately every 20,000 miles or 24 months, whichever comes first. It includes everything in an A service plus more comprehensive inspections, including: 

• Brake fluid replacement 

• Air filter change 

ASSYST PLUS service interval display 

Some A-Class models have ASSYST PLUS, which displays the distance or time remaining before your next service on the dashboard. 

This technology means you don’t have to think about when your car was last serviced or count the distance you’ve travelled since then; the car does it for you. 

The ASSYST PLUS system may shorten the service interval in the following situations: 

• The car is mainly used for short distance driving 

• The engine is left idling for long periods 

• There are frequent cold start phases 

• Regeneration of the DPF in diesel models is interrupted 

Want to learn more about vehicle servicing? Check out the following guides: 

• What's the difference between a full service and an interim service? 

• How much should a full service cost? 

• How much should an interim service cost? 

• The ultimate guide to car maintenance 

Tyre pressure

What are the tyre pressures for a Mercedes A-Class? 

The recommended tyre pressure varies depending on the spec and engine of your car. The table below shows tyre sizes and pressures listed for the A-Class on TyrePressures.com. 

However, you should always check this information before adjusting your tyres. You can find the correct pressure: 

• In the vehicle handbook/owner’s manual. 

• Printed on the sill of the driver’s door. 

• On the inside of the fuel tank cap. 

Read our guide to tyre pressure for more information. 

How to reset the tyre pressure on a Mercedes A-Class 

The reset method can vary between different model years and configurations. If unsure, consult your owner’s manual. 

2012-2018 

• Top up your tyres to the correct pressure. 

• Switch the ignition on. You don’t need to start the engine. 

• From the mileometer screen on the dashboard, press the left arrow on the steering wheel controls until you reach ‘service’. Press ‘OK’ to enter. 

• Scroll down and press ‘OK’ to enter the ‘tyre pressure’ screen. 

• Press the down arrow. You should see a message asking if you want to use the current pressures as the reference values. 

• Press ‘OK’ to confirm. 

• Drive around for a few minutes. You will see the new tyre pressures on the screen. 

2018-present 

• Switch the ignition on. You don’t need to start the engine. 

• Press the home button on the right side of the steering wheel. 

• Select ‘service’. 

• Scroll down and select ‘tyres’. 

• Top your tyres up to the correct pressure. 

• Scroll down. You will see a message asking if you want to use the current pressures as new reference values. 

• Click ‘OK’. 

Engine oil

It’s crucial to use the correct engine oil – find out why in this guide.  

5W-30 and 5W-40 oil grades are commonly used in Mercedes models. 

However, the recommended oil can vary between different A-Class engine configurations and depending on whether the car uses petrol or diesel. Your owner’s manual will provide information about the right oil for your vehicle. 

Recommended oil specifications 

Mercedes has several engine oil specifications, known as MB approvals, which indicate oil quality and compatibility with their engines. 

The following specifications are often used for A-Class models: 

• MB 229.5: High-performance synthetic oils suitable for petrol engines. 

• MB 229.51: Low SAP (sulphated ash, phosphorous, and sulphur) oils suitable for petrol engines and diesels with a DPF. 

• MB 229.71: A newer specification for lower-viscosity oils that promote engine efficiency. Typically used in some modern engine variants. 

What is the oil capacity of a Mercedes A-Class? 

Oil capacity varies depending on the engine size and model year. The A-Class generally requires between 4.5 and 6.5 litres.  Before changing your oil, check this information in your owner’s manual to ensure you don’t overfill the system. 

Need help checking and topping up your engine oil? Read this guide. 

Battery

What battery do I need for my Mercedes A-Class? 

The type and size of the battery will depend on the model’s configurations. The table below provides a general guide but should be checked against the information in your owner’s manual. 

The W177 plug-in hybrid model requires a high-voltage lithium-ion battery.  

How to look after the battery of your Mercedes A-Class 

The top three things you can do to prolong your battery’s life are: 

• Keep it clean and free from corrosion. 

• Use your car regularly and do some longer journeys. 

• Get it checked – this is done during a full service. 

Read about more battery maintenance tips here. 

Warning lights

What do the warning lights mean on a Mercedes A-Class? 

Dashboard warning lights are triggered by the car’s electronic control unit (ECU) when a problem is detected. You can learn some information by looking at the shape and colour of the light, but for a detailed diagnosis, you’ll usually need to book a diagnostic test. 

• Red lights indicate a severe problem. You should stop driving and contact a mechanic. 

• Yellow lights are less urgent – you can continue driving to your destination, but you should book your car into a garage. 

Learn more about car warning lights and what they mean in this guide. 

Mercedes A-Class warning lights you might not know 

Mercedes electronic parking brake warning 

This warning light looks like a yellow ‘P’ with a wrench or exclamation mark. If it's red, it indicates a fault with the electronic parking brake; a yellow light can mean a service is needed.   

Mercedes PARKTRONIC system fault 

The PARKTRONIC warning light is a ‘P’ with radar waves or a cone icon next to it. This means there is an issue with the parking assist sensors – they could be blocked, dirty, or malfunctioning. 

Mercedes Attention Assist warning 

This warning light is a coffee cup icon. It means the Attention Assist system has detected signs of drowsy driving based on steering input and time on the road. If you see this light and you’ve been driving for a long time, it’s a good idea to stop for a rest. 

Spotted a warning light but don’t know what’s causing it? Don’t guess – book a diagnostic test! 

Common problems

Whether you’re already a proud A-Class owner or you’re in the market for one, it’s helpful to know what kind of problems the model experiences.    

 Our Mercedes A-Class common problems guide explores this topic in detail, so we’ll just cover two top issues here. 

1. Electrical issues 

In WhatCar?’s 2023 Reliability Survey, owners of petrol and diesel models reported various electrical issues with the latest A-Class, including: 

• Infotainment system malfunctions 

• Faulty sensors 

• Persistent warning lights 

While replacing a bad sensor is relatively easy and cheap, warning lights without an apparent cause can be tricky to repair, often requiring expert knowledge from a Mercedes specialist. 

2. Blocked DPF 

The most common complaint from diesel A-Class owners relates to the diesel particulate filter, which can get blocked if the conditions for regeneration (self-cleaning) aren’t met.   

This issue isn’t exclusive to the A-Class – it can affect all diesel models. The good news is that it’s easily avoidable. Add a few longer motorway journeys into your monthly driving routine, and the DPF should be fine. It’s also important not to shut the car off while the filter is midway through regenerating.  

Learn more about how to avoid DPF problems in this guide. 

Need help diagnosing car problems? Check out the following guides for advice: 

• Diagnose car problems & find the right fix 

• Diagnose strange noises in your car & find a fix 

Top Mercedes A-Class questions and topics

How to open the bonnet of a Mercedes A-Class 

2012-present models 

• Pull the red bonnet release lever located above the brake pedal. You will hear the bonnet click open. 

• Slide your fingers under the bonnet slightly to the left of the Mercedes badge. Inside is a small yellow tab. Push it to the left. 

• Open and secure the bonnet. 

Is the Mercedes A-Class front wheel drive? 

Most Mercedes A-Class models are front-wheel drive. Some higher-performance versions are available with four-wheel drive. 

Where to put coolant in a Mercedes A-Class 

The coolant reservoir is in the engine bay on the driver’s side. Remove the cap by turning it anticlockwise and pour the coolant in. 

Wondering what coolant to use for your car? This guide can help. 

How to turn on ambient lighting in a Mercedes A-Class 

Scroll through the apps on the central display screen and select ‘comfort’. From here, you can change the ambient lighting brightness and colour settings.  

If you found this guide helpful, you might also like:

• Common problems with the Mercedes A-Class

• How much does an MOT cost for a Mercedes?

• Car ownership 101: everything you need to know

• The ultimate guide to car maintenance

• How does a car work?