Mercedes-Benz
SLK
Porsche
Boxster
Mercedes-Benz SLK vs Porsche Boxster: 2015 Comparison
The short answer
Based on available data, the Mercedes-Benz SLK comes out ahead of the Porsche Boxster on fuel economy and power. Check the specs table and owner sentiment below for the full comparison before deciding between the two. Both are covered by real owner reports on CarWizz.
Specs side by side
What owners say
SLK
Overall
Sentiment is mixed and heavily dependent on generation, specific engine, and ownership expectations. For the earliest R170 generation (1997-2004), owners report these as surprisingly reliable and robust budget-friendly classic convertibles when purchased cheaply (e.g., £1,000 GBP / ~$1,260 USD), praised for their bulletproof engines, comfortable heated seats, and effective "Airscarf" neck heating system. The hardtop convertible mechanism is generally seen as a durable asset, though its seals require regular lubrication.
Best version to buy
Insufficient owner data available to declare a definitive "best" version. Isolated positive remarks exist for the R170 for its simplicity and value, and for the R172 SLK55 AMG for its powerful V8 engine.
Known issues
- ⚠Hydraulic convertible top failure (R171): roof operation slows, makes loud noises, leaks hydraulic fluid (causing skin irritation), eventually fails completely; repair cost often cited as exceeding vehicle value. Frequency: recurrent.
- ⚠Engine timing chain/balance shaft issues (R171 M272 V6): timing chain noise, potential for catastrophic failure due to faulty balance shaft gears on 2004-2007 models. Frequency: recurrent.
- ⚠Electrical faults and sensor failures: various error codes for oxygen sensors, air pumps, camshaft timing sensors, power steering pressure valves, and other components; can cause rough running or warning lights. Frequency: recurrent.
Boxster
Overall
Owner sentiment is overwhelmingly positive regarding the driving experience, with the Boxster consistently praised for its exceptional handling, fun factor, and the special feeling it provides. The consensus is that it is a "perfect" or "best" driving car, particularly on back roads, offering a level of engagement and chassis dynamics that are highly valued. However, this enthusiasm is heavily tempered by very frequent and serious warnings about the high and unpredictable costs of ownership, especially for older models (primarily the 986 and 987 generations).
Best version to buy
The 987 generation (2005-2012) is generally recommended over the earlier 986 as a "better car all around," being more modern, refined, and having a better interior (including a glass rear window and glove box). Within a specific comparison, a 2007 base model was favored over a 2000 Boxster S for a $5,000 USD price difference.
Known issues
- ⚠High and unpredictable maintenance/repair costs: very frequent. IMS (Intermediate Shaft) bearing failure (986 and early 987): can cause catastrophic engine failure. Frequency: very frequent.
The verdict
The Mercedes-Benz SLK is the better choice for most buyers.
It has stronger reliability sentiment in owner reports than the Porsche Boxster, based on the data above. If the specific known issues on the Mercedes-Benz SLK are a dealbreaker, the Porsche Boxster is worth a closer look instead.
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Frequently asked questions
Which is more reliable, the Mercedes-Benz SLK or the Porsche Boxster?
Owner reports lean more positive on reliability for the Mercedes-Benz SLK than the Porsche Boxster. See the known issues comparison above for the specific concerns owners report on each.
Which is better for families, the Mercedes-Benz SLK or the Porsche Boxster?
Data on family-specific factors like cargo space is limited for one or both models, but based on available reports, both are positioned as practical daily drivers. Check the specs table above for seating and body type.
Which has better fuel economy, the Mercedes-Benz SLK or the Porsche Boxster?
The Mercedes-Benz SLK is more fuel-efficient on paper: 8.4 L/100km combined versus 9.9 L/100km for the Porsche Boxster, based on the best-equipped catalogued version of each.
Which is cheaper to maintain, the Mercedes-Benz SLK or the Porsche Boxster?
Exact maintenance costs aren't in our data, but reliability signals above are the closest proxy: fewer reported issues generally means lower repair costs over time.