2012 Mercedes-Benz ML 2.1L Diesel · 81 GW

The 2.1-litre diesel ML is relatively frugal for a large SUV, with combined fuel economy typically in the mid-30s mpg in real-world driving. Annual road tax for a 2012 diesel of this size is likely to sit in the higher bands, so check the V5 document for the exact rate. Insurance for an ML is moderate to high — these are large, premium SUVs, and parts and labour at main dealers are expensive.

Maintenance costs are the bigger concern: replacement tyres are four-figure jobs on a vehicle this size, and the MOT record shows tyres have been an issue at almost every test. Common expensive items on this generation of ML include the air suspension components, the diesel particulate filter, and injector servicing. Budget carefully and assume at least one major service bill within the first year of ownership. Estimated annual running cost: £2,200-£2,800.

Given the November 2023 MOT failure, pay particular attention to the tyres — check all four for cracking, perishing, and uneven wear, especially the inner edges, which were flagged in 2024. Inspect under the car for any signs of oil leaks; the 2023 test recorded an oil leak that was deemed not excessive, but it is worth checking the engine bay and underside for fresh residue. Test every exterior lamp personally, as the offside rear position lamp issue has appeared twice in the MOT record.

The 2.1-litre diesel engine (OM651 family) is known within the trade for potential issues with the diesel particulate filter, turbo actuator, and EGR valve, particularly at higher mileages. On the test drive, listen for any turbo whistle or rattles from the engine bay, and check for excessive smoke on startup or under acceleration. Examine the air suspension (if fitted) for any sagging at the corners, as replacement struts and compressors are costly. Finally, confirm the vehicle starts cleanly when cold, as diesel issues often manifest before the engine is warm.