# Mercedes GLS — Used Car Buying Guide

AutoScout's analysis of the Mercedes GLS on the UK used-car market. Backed by 33 million DVSA MOT tests, current AutoTrader pricing, and depreciation curves derived from CAP/Glass's Guide data.

Live interactive report: https://autoscout.fyi/cars/mercedes-gls

## Verdict

- **Best value year**: 2019
- **Ideal trim**: GLS 400d 4MATIC AMG Line Premium
- **Target mileage**: 40,000–60,000 miles
- **Max previous owners**: 2
- **Target price**: £47,500

## Why this model

The Mercedes GLS is a fantastic choice if you need serious space, luxury, and a commanding presence on the road. It's essentially an S-Class SUV, offering incredible comfort for all seven passengers, a high-quality interior, and a smooth, powerful ride. For a large family or someone who frequently carries passengers and luggage, it's hard to beat its blend of practicality and prestige. While it's a big car, the diesel engines offer reasonable economy for its size, and the driving experience is surprisingly refined.

## What you should pay

For a 2019 Mercedes GLS 400d AMG Line Premium with around 40,000-60,000 miles, you should aim to pay in the region of £45,000-£50,000. Prices can vary quite a bit based on specific options, condition, and seller, so be prepared to negotiate. Listings often start higher, but there's usually room for movement, especially if the car has been on the market for a while.

## Which trim to buy

The GLS 400d 4MATIC AMG Line Premium offers the best balance of performance, features, and value. The 400d engine is a powerful and refined diesel, providing plenty of grunt for such a large vehicle without being overly thirsty. The AMG Line trim adds a sportier aesthetic with larger wheels and body styling, which really suits the GLS. The 'Premium' package typically includes desirable upgrades like a panoramic sunroof, Burmester sound system, and enhanced interior lighting, making the cabin feel even more luxurious and enjoyable for all occupants. It's a significant step up in feel and features from the entry-level trims without the much higher price tag and running costs of the V8 petrol models.

## What to check before you buy

- Air suspension problems (leaks, compressor failure)
- AdBlue system faults (sensors, heaters)
- Infotainment system glitches
- DPF (Diesel Particulate Filter) issues if mainly used for short journeys
- Electrical gremlins (e.g., parking sensors, cameras)

## Running costs

Running a GLS isn't cheap, but for a car of this calibre, it's manageable. Fuel costs for the 400d diesel will be around 18-20 pence per mile based on current diesel prices and real-world MPG. Road tax (VED) for cars that cost over £40,000 new is currently £195 per year plus an additional £390 supplement for five years from the second year of registration, so expect around £585 annually. Insurance will be high due to its value and performance, likely in the £1,000-£2,000+ range depending on your personal circumstances. Servicing can also be costly at main dealers, so consider independent Mercedes specialists.

## Key stats

- **Fuel Type**: Diesel
- **Horsepower**: 330 hp
- **Mpg**: 32-35 mpg (combined)
- **Reliability Score**: 7/10 (Good)
- **Safety Rating**: Not directly rated, but similar Mercedes SUVs achieve 5-star Euro NCAP

## Trim comparison

| Trim | Price new | Price used | Key features |
| --- | --- | --- | --- |
| GLS 350d 4MATIC AMG Line | £75,000 | £42,000 | 21-inch AMG alloy wheels; AMG bodystyling; LED headlights |
| GLS 400d 4MATIC AMG Line Premium | £80,000 | £47,500 | All AMG Line features; Panoramic sliding sunroof; Burmester surround sound system |
| GLS 400d 4MATIC AMG Line Premium Plus | £85,000 | £52,000 | All AMG Line Premium features; Energizing Package Plus; Heated and ventilated front seats |

## Depreciation forecast

| Year | Estimated value | Retention |
| --- | --- | --- |
| 2026 | £47,500 | 100% |
| 2027 | £40,375 | 85% |
| 2028 | £34,289 | 72% |
| 2029 | £29,450 | 62% |
| 2030 | £25,650 | 54% |

Buying a 2019 GLS in 2026 means you're letting the first owner absorb the steepest part of the depreciation curve. Luxury SUVs like the GLS lose a significant chunk of their value in the first few years. By picking up a 6-7 year old model, you're getting a lot of car for your money, and while it will continue to depreciate, the rate will be slower than a newer model. This year offers a good balance of modern features, reasonable mileage, and a much more accessible price point.

Total value lost since new: 46%.

## Alternatives to consider

- [BMW X7](https://autoscout.fyi/cars/bmw-x7.md)
- [Audi Q7](https://autoscout.fyi/cars/audi-q7.md)
- [Land Rover Discovery](https://autoscout.fyi/cars/land-rover-discovery.md)

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Source: AutoScout (https://autoscout.fyi). Part of a review of the UK used-car market across 500+ models.