Mercedes-Benz S-Class: A data-led used car review.

The Mercedes-Benz S-Class is Mercedes’ flagship luxury saloon, designed to showcase advanced technology, refinement and comfort. Long regarded as a benchmark in the executive car segment, it combines powerful engines, cutting-edge driver assistance systems and high levels of interior sophistication. [1] 

In the used market, the S-Class offers exceptional comfort and prestige, often for a fraction of its original list price [2]. However, due to its advanced engineering and complex onboard systems, it takes 3rd place on our Lower Reliability list for 2026, compiled using data from our Reliability Index.

This does not mean issues are guaranteed. Many examples provide years of refined driving when properly maintained. However, the data does suggest that potential repair costs should be carefully considered as part of ownership planning, alongside an extended warranty.   

With a solid service history, sensible ownership and realistic planning for long-term running costs, many drivers continue to enjoy the strengths of the S-Class with confidence.  
 

Mercedes S-Class – Reliability Index data.

*Figures are indicative and based on average Mercedes-Benz S-Class repair data. Individual vehicles may vary. 

What our data suggests about used Mercedes S-Class reliability: 

Based on our historic repair data, the Mercedes-Benz S-Class takes 3rd place in our Lower Reliability list for 2026. A little sensible budgeting and forward-planning is recommended for people considering purchasing this vehicle. It’s a premium vehicle, which often means luxury and class, but can also mean higher than average repair frequency and related repair costs. 

The S-Class reports significant average repair costs of £1,970.86. However, this is understandable as it is a larger car with various more complex and expensive systems that could require repairs.  

Emissions failures are the most commonly-featured repair request for this model, reflecting both tightened emissions standards and the increased complexity of nitrous oxide sensors on modern vehicles – which, when damaged, can misreport emissions warning lights on the dashboard. [3] 

Large luxury vehicles like the S-Class can combine multiple advanced systems, including: 

• Air suspension 
• Extensive driver-assistance technology 
• High-output engines 
• Complex infotainment and comfort systems 

As a result: 

• Electrical and technology-related repair requests are more common than in simpler vehicles 
• Average repair costs are higher due to specialist labour and premium parts 
• The gap between routine maintenance and worst-case repair outcomes can be significant 

An Overall Reliability Score of 19.2/100 reflects the S-Class’s sophistication rather than poor build quality or a lack of durability. Vehicles at this level are engineered for comfort and innovation, but it is that very sophistication that can increase financial exposure as they age. 

A full-service history and careful ownership make a substantial difference. 

Why reliability can vary between S-Class models:  

While the Mercedes-Benz S-Class can be associated with higher risk ownership, reliability is never guaranteed. Factors that can influence repair likelihood include: 

• Servicing and maintenance history: Having your car serviced and maintained at the manufacturer’s specified intervals can reduce repair likelihood. 

• Mileage and driving style: Accelerate gently, avoid harsh braking and try to maintain steady speeds. 

• Urban use versus longer motorway journeys: Frequent, short trips (where the car’s engine never reaches full operating temperature) can increase stress on starter motors, reduce battery life and cause increased wear on various engine components [4].  

• Previous owners and care standards: Insist on a full-service history and try to investigate previous owners’ care for the car. 

• Hybrid vs petrol powertrains: Hybrid S-Class models, for example, introduce additional electrical components [5] that may alter long-term repair patterns, while higher-mileage examples may naturally face wear-related repairs sooner. 

Our reliability data is best used as a guideline, not a guarantee. Two identical S-Class models can perform very differently depending on how they’ve been looked after. 

What people love about the Mercedes S-Class: 

People love the Mercedes-Benz S-Class for its unmatched luxury, whisper-quiet comfort and advanced tech. With refined performance, cutting-edge safety features and an exquisitely crafted interior, it delivers a serene, first-class experience. Elegant, prestigious and supremely comfortable – the S-Class sets the standard for executive driving. 

Owners choose the S-Class for its comfort, presence and advanced features rather than affordability. 

Commonly praised strengths include: 

• Exceptional ride comfort and refinement 
• Advanced safety and driver-assistance systems 
• High-quality interior materials and craftsmanship 
• Strong motorway performance and long-distance ability 

For many drivers, the S-Class represents luxury motoring at its most complete. It continues to attract buyers in the used market despite some ownership complexity.  

Mercedes S-Class safety: 

Euro NCAP has not crash tested recent generations of the S-Class, due to it being a low-volume, luxury vehicle.  

However, the model is widely regarded as a leader in introducing new safety systems, many of which later filter down into smaller Mercedes models. 

How much does a used Mercedes S-Class cost? 

Used prices vary significantly depending on generation, engine and specification, but typical UK examples include:  

Prices will vary depending on age, mileage, spec and general condition. Price ranges from Autotrader, March 2026. Prices subject to change. 

Buyers should factor in not just the purchase price, but also the likelihood of repairs and what they might cost to fix. In 2025, the RAC reported that two-thirds (65%) of drivers have had to fork out for unexpected car repair costs in the last year [6] – up from 59% last year.  

With the average S-Class repair cost coming in at £1,970, it’s important to be confident your budget can accommodate potential repair work over time.  

Is the Mercedes S-Class a sensible used buy? 

The S-Class may suit you if: 

• You prioritise comfort, refinement and advanced features 
• You understand and plan for higher running costs 
• You choose a well-maintained example with comprehensive service history 
• You are comfortable budgeting for premium repair costs 

Things you may wish to consider: 

• Repairs can be significantly more expensive than mainstream cars 
• Advanced systems increase potential complexity as the car ages 

No car is inherently good or bad – ownership risk depends on maintenance, usage, mileage and the quality of previous care. 

Warranty considerations: 

Given the S-Class’s complexity, some owners consider a car warranty to help manage the financial impact of unexpected repairs once the manufacturer warranty has expired. 

Warrantywise plans start from just £48 per month for the S-Class, helping drivers spread the cost and budget for unexpected repair bills. (Prices may vary depending on your specific warranty plan.)

If explored, it’s sensible to: 

• Carefully review what is and isn’t included 
• Treat it as a budgeting tool rather than a guarantee 
• Balance the cost against potential repair exposure and annual mileage 

A warranty should support long-term planning, not replace thorough pre-purchase inspections and proper servicing. 

Speak to one of our friendly warranty experts to find out if a warranty is right for you. Or start your warranty quote for your Mercedes-Benz S-Class today by clicking the link or calling our team on 01254 355 100. 

Explore other models on our lower reliability scores list:

Data note: This overview uses historical repair request data as one part of a broader ownership picture. It does not guarantee whether an individual vehicle will or will not experience issues. Reliability is influenced by many factors, including maintenance, usage and vehicle condition. These aspects should always be considered alongside professional inspections and service records.

Sources:

Reliability Index scores are based on historical repair request data, including 1. Repair request frequency, 2. Labour hours, 3. Average vehicle age at repair and 4. Average vehicle mileage at repair between Jan 2023 and Jan 2026. The data includes vehicles aged three to fifteen years old, with a minimum of 250 vehicles on plan per model.  

Average repair request values reflect the data period analysed. Ongoing increases in labour and parts costs may affect future repair costs. All data is sourced from Warrantywise’s internal Reliability Index and is believed to be accurate at the time of publication. Warrantywise may update this information as new Index data becomes available.  All car class/segment titles referred to taken from euroncap.com.

External sources of information:

[1] S-Class flagship saloon 

[2] S-Class can be great value used 

[3] Faulty NOX sensors can cause emissions failures 

[4] Frequent, short trips worse for your car 

[5] Hybrid models introduce additional systems 

[6] RAC – two thirds of drivers hit with repair costs 

Disclaimer: The information provided in this guide is for general informational purposes only and does not constitute legal or financial advice.