Mercedes SL400 Valuation: 20 ads analysed

Market overviewWhat is the fair price of a used Mercedes SL400? We have 20 for sale. Prices from £16,995 to £41,990. See variants (AMG line, AMG, AMG Line Premium) and check the valuation.

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Super price

Good price

Fair price

A bit pricey

Expensive

-4%
1 / 4

Used (2019) Mercedes SL400 AMG line 367 HP | Good price

- AMG Line 2dr 9G-Tronic

  • 2019
  • 43,000 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 367 HP (269 kW)
  • mpg9.1
  • CO2191 g CO2/km comb.
  • Details
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Good price

£27,795
£28,995
Verified Marketplace
DE737HL, Derbyshire
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1 / 4

Used (2015) Mercedes SL400 AMG 333 HP | Good price

SL AMG Sport 2dr Auto

  • 2015
  • 38,626 miles
  • Trim levelAMG
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 333 HP (244 kW)
  • Details
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Good price

£20,999
Marketplace
NR18 0SP Wymondham, Norfolk
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1 / 4

Used (2016) Mercedes SL400 AMG line 367 HP | Good price

SL 3.0 V6 AMG Line Roadster 2dr

  • 2016
  • 14,051 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 367 HP (269 kW)
  • Details
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Good price

£29,990
Marketplace
NG13 9EW Whatton, Nottinghamshire
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1 / 3

Used (2018) Mercedes SL400 AMG Line Premium | Good price

SL AMG Line Premium 2dr 9G-Tro

  • 2018
  • 30,967 miles
  • Trim levelAMG Line Premium
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • Details
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Good price

£37,495
Marketplace
DN4 9LX Doncaster, South Yorkshire
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1 / 4

Used (2017) Mercedes SL400 AMG line 367 HP | Super price

SL 3.0 V6 AMG Line Roadster 2dr

  • 2017
  • 90,300 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 367 HP (269 kW)
  • Details
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Super price

£22,495
Marketplace
PL12 6LZ Saltash, Cornwall
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1 / 4

Used (2016) Mercedes SL400 AMG | Good price

SL AMG Sport 2dr Auto

  • 2016
  • 70,000 miles
  • Trim levelAMG
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • Details
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Good price

£19,990
Marketplace
MK42 9SU Bedford, Bedfordshire
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-7%
1 / 4

Used (2016) Mercedes SL400 AMG line | Fair price

SL 3.0AMG Line Auto 2dr

  • 2016
  • 43,000 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • Details
autouncle-certified

Fair price

£27,795
£29,995
Marketplace
DE73 7HL Derby, Derbyshire
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-1%
1 / 3

Used (2017) Mercedes SL400 AMG line 367 HP | Fair price

SL AMG Line 2dr 9G-Tronic

  • 2017
  • 59,000 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 367 HP (269 kW)
  • Details
autouncle-certified

Fair price

£28,663
£28,992
Marketplace
LS23 7FP Wetherby, Thorp Arch Estate, West Yorkshire
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1 / 4

Used (2017) Mercedes SL400 AMG line | Fair price

SL AMG Line 2dr 9G-Tronic

  • 2017
  • 31,806 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • Details
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Fair price

£30,999
Marketplace
HP2 7AZ Hemel Hempstead, Hertfordshire
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1 / 4

Used (2015) Mercedes SL400 AMG 333 HP | Fair price

SL 3.0 AMG Sport Convertible 2dr

  • 2015
  • 85,762 miles
  • Trim levelAMG
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 333 HP (244 kW)
  • Details
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Fair price

£17,299
£16,799
Marketplace
YO19 4SH York, North Yorkshire
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-3%
1 / 4

Used (2015) Mercedes SL400 AMG 333 HP | Fair price

SLAMG Sport 2dr Auto

  • 2015
  • 68,541 miles
  • Trim levelAMG
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 333 HP (244 kW)
  • Details
autouncle-certified

Fair price

£20,435
£21,237
Marketplace
L40 8HS Scarisbrick, Lancashire
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1 / 3

Used (2015) Mercedes SL400 AMG 333 HP | Fair price

SL AMG Sport 2dr Auto

  • 2015
  • 29,750 miles
  • Trim levelAMG
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 333 HP (244 kW)
  • Details
autouncle-certified

Fair price

£24,495
Marketplace
BL1 3DE Bolton, Manchester
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1 / 4

Used (2015) Mercedes SL400 AMG 333 HP | Fair price

SL-ClassAMG Sport 2dr Auto

  • 2015
  • 94,000 miles
  • Trim levelAMG
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 333 HP (244 kW)
  • Details
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Fair price

£16,995
Marketplace
LS13 4AD Leeds, West Yorkshire
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Used (2020) Mercedes SL400 Edition | Fair price

SLS 3.0 V6 Grand Edition G-Tronic+

  • 2020
  • 58,000 miles
  • Trim levelEdition
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • Details
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Fair price

£34,995
Marketplace
Hampshire, Hampshire
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1 / 3

Used (2016) Mercedes SL400 AMG 333 HP | A bit pricey

- AMG Sport 2dr Auto

  • 2016
  • 29,750 miles
  • Trim levelAMG
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 333 HP (244 kW)
  • mpg7.7
  • CO2179 g CO2/km comb.
  • Details
autouncle-certified

A bit pricey

£24,495
Verified Marketplace
BL13DE, Manchester
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1 / 4

Used (2020) Mercedes SL400 Premium 367 HP | A bit pricey

SL Convertible Grand Edition

  • 2020
  • 19,669 miles
  • Trim levelPremium
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 367 HP (269 kW)
  • Details
autouncle-certified

A bit pricey

£43,950
Marketplace
WC1E 7DP London, London
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1 / 4

Used (2019) Mercedes SL400 AMG line 367 HP | Expensive

SL 3.0 V6 AMG Line (Premium)

  • 2019
  • 20,000 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 367 HP (269 kW)
  • Details
autouncle-certified

Expensive

£41,990
Marketplace
RH12 3JP Horsham, West Sussex
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Used (2018) Mercedes SL400 AMG line 367 HP

SL 3.0 V6 AMG Line Convertible 2dr

  • 2018
  • 19,400 miles
  • Trim levelAMG line
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 367 HP (269 kW)
  • Details
£39,995
Not evaluated
Marketplace
AL3 4DR St. Albans, Hertfordshire
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Used (2015) Mercedes SL400 2LOOK Edition 333 HP | Rare vehicle

SL 2LOOK Edition 2dr Auto

  • 2015
  • 49,657 miles
  • Trim level2LOOK Edition
  • 3.0L Petrol
  • Cabriolet
  • Automatic
  • 333 HP (244 kW)
  • Details
£23,970
Rare vehicle
Marketplace
ME1 3QX Rochester, Kent
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Showing 1 - 19 of 19 results

How much does the Mercedes SL400 depreciate?

Used Mercedes SL400

A used Mercedes SL400 (2015) model loses about £42 per month in value.


Factors that affect the depreciation of a Mercedes SL400:
- Mileage driven
- Maintenance
- Service history


Depreciation is an important part of calculating the total cost of owning a Mercedes SL400. In addition to the monthly depreciation of £42, you should also factor in fuel costs, road tax, insurance and maintenance (including tyres and car washes) to get the full monthly cost.

How much does a used Mercedes SL400 cost? Prices, ratings and depreciation by model year

How much does a used Mercedes SL400 cost? Prices, ratings and depreciation by model year

Model year

Price range*

Avg. Price

Median Mileage

Depreciation
(12 mth.)

Cars for sale

2018 Mercedes SL400

£32,401 - £39,995£36,63030,967 miles-< 10

2017 Mercedes SL400

£22,495 - £30,999£27,38659,000 miles-< 10

2016 Mercedes SL400

£19,990 - £29,990£25,86836,375 miles-£1,380< 10

2015 Mercedes SL400

£16,995 - £24,495£20,69959,099 miles-£500< 10

*The 'Price range' column shows the prices at the 5th and 95th percentiles of cars in the current market

The data is based on the cars currently listed on AutoUncle

Last updated: 28 January 2026

Comparison of Mercedes SL400 variants and prices

Below you can compare prices and depreciation for the 2 most popular Mercedes SL400 variants. The table is updated daily with data from the market in United Kingdom.

Comparison of Mercedes SL400 variants and prices

Variant

Price range*

Avg. Price

Median Mileage

Depreciation
(12 mth.)

Cars for sale

🏆 The most popular

Mercedes SL400 AMG line

£22,495 - £41,990£31,61438,110 miles-£2,300< 10
💰 The budget choice

Mercedes SL400 AMG

£16,995 - £24,495£20,67368,541 miles-£120< 10

*The 'Price range' column shows the prices at the 5th and 95th percentiles of cars in the current market

The data is based on the cars currently listed on AutoUncle

Last updated: 28 January 2026

Which variant should you choose?

💰 The budget choice

The AMG is the cheapest entry point with an average price of £20,673.

Accuracy will improve as more cars from this variant become available

🏆 The most popular

There are the most AMG line for sale right now (9), which gives you the most options to choose from.

Accuracy will improve as more cars from this variant become available

📈 The best value

The AMG has held its price stable with minimal loss in value over the past year (-£120).

Accuracy will improve as more cars from this variant become available

Mercedes SL400 (model year 2015) - Price development for the last 12 months and price projection for the next 6 months (January 2025 - June 2026)

Monthly price data with average prices and price ranges

Month

Average market price

Lowest market price

Highest market price

Calculation method

2025 - January
£22,460
£20,060£24,840
Estimate
2025 - February
£22,400
£19,880£24,920
Estimate
2025 - March
£22,760
£20,060£25,480
Estimate
2025 - April
£23,160
£20,380£25,940
Estimate
2025 - May
£22,260
£19,860£24,660
Estimate
2025 - June
£21,900
£19,520£24,260
Estimate
2025 - July
£21,540
£19,200£23,880
Estimate
2025 - August
£21,180
£18,860£23,480
Estimate
2025 - September
£20,940
£17,920£23,960
Estimate
2025 - October
£21,280
£18,400£24,140
Estimate
2025 - November
£21,620
£18,900£24,320
Estimate
2025 - December
£21,960
£19,380£24,520
Estimate
2026 - February
£22,120
--
Forecast
2026 - March
£22,200
--
Forecast
2026 - April
£22,280
--
Forecast
2026 - May
£22,360
--
Forecast
2026 - June
£22,460
--
Forecast

All estimates and forecasts are based on actual market data

Last updated: 28 January 2026

Average Monthly Depreciation

A summary of the past 12 and an estimation of the next 6 months.

Past 12 months

-£500

Next 6 months

£500

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Price checked by AutoUncle

Super price

Good price

Fair price

A bit pricey

Expensive

Interested in finding a great deal on a used Mercedes SL400?

Are you considering purchasing a used sports car? Then the Mercedes SL400 is an excellent choice. AutoUncle present 24 options sourced from different dealership websites and online marketplaces.

How much does a used Mercedes SL400 cost?

Currently, the prices for a pre-owned Mercedes SL400 start at £16,995 and go up to £44,950.

The German car is being offered at different prices relying on mainly five factors: year, engine size and performance, fuel economy, number of miles as well as trim level.

For example, a newer model with low mileage or a premium version equipped with a high-performance engine generally demands a higher price than a car from an older model year, with higher mileage and no optional extras.

What versions of the Mercedes SL400 are available based on equipment?

The Mercedes SL400 is offered in a varied array of trim editions, addressing different driving styles and essentials. The most popular ones are:

As you considers the cost of a used Mercedes SL400, it's fundamental to examine vehicles sharing identical trim level. If not, you might draw an inaccurate conclusion about which car to buy.

What fuel types are available for the Mercedes SL400?

The predominant fuel variant for the Mercedes SL400 is petrol.

When contemplating fuel type choices, reflecting on your driving habits is important. What's your typical weekly driving mileage? Are your trips usually short or do they cover longer distances?

If you primarily drive short distances, electric, plug-in hybrid or petrol is typically a good fit. For longer commutes, a newer electric car is a good alternative - especially with access to charging. For longer daily commutes, a modern electric car is often suitable - especially if you can charge at home or at work. Despite the rise of electric cars, diesel can still be useful for long journeys and lack of charging options. Note that in some countries, high-emission diesel engines have been banned from entering certain cities.

What body types is the Mercedes SL400 available in?

On AutoUncle, the Mercedes SL400 is exclusively offered in the cabriolet body style. Cabrios and convertibles give the driving experience a new dimension. Thanks to their excellent hoods and weather gear, most models are fit for year-round use these days. Thickener is applied underneath the car to strengthen the chassis in lieu of a roof, which means that convertibles have a tendency to be heavier than normal cars.

Curious about what other alternatives are available?

The Mercedes SL400 faces stiff competition within its segment.

Most popular choices as an alternative to the Mercedes SL400

  • BMW 420
  • Audi TT
  • Mazda MX5

With a current inventory of 1,733 available models on AutoUncle, the BMW 420 stands out as the top alternative to the Mercedes SL400. On average, the BMW 420 costs £17,750.

The next best alternative car is the Audi TT with 1,042 cars currently for sale with an average sales price of £13,990. Another recommended alternative is Mazda MX5 with 689 cars for sale an average price tag of £14,695.

Thinking about investing in an electric vehicle?

When considering an electric vehicle that matches the calibre of the Mercedes SL400, here are some few suggestions:

Can't seem to locate an electric car that matches your needs? View our complete collection of electric cars here.