Used Mitsubishi ASX review and buying guide (2010 to 2021): which one to buy and what to check

Which used Mitsubishi ASX should you buy?

Buy a diesel ASX that's spent its life on longer runs. The problem that comes up again and again on this car is the particulate filter failing to regenerate, which sends diesel into the sump and thins the oil. It's been reported on 1.8 and 2.2 diesels from 2013 and 2014, and nothing shows later cars are clear of it, so a newer one isn't automatically safer.

The 1.6 petrol doesn't appear in any of the oil dilution reports, but it's short on pace and there's very little written about it at all, so treat that as a thin record rather than a clean one. Nothing in the reports covers a car built after 2015 either, which tells you nothing either way about the later ASX.

If you need roof bars, look at a 15-plate or later ASX. One 2014 owner found that neither Mitsubishi's own bars nor aftermarket ones would fit that car's rails, and the dealer's only answer was to fit new rails. The 15-plate cars got deeper rails that do take them, so it's worth checking the plate before you travel.

Which ASX engines and gearboxes are the safe choices?

A diesel's only a safe choice if it's been driven far enough to keep its particulate filter clean, because both the 1.8 and the 2.2 have been reported with failed active regenerations. When that happens, the extra diesel injected to burn the filter clean ends up in the sump, raising the oil level and thinning it: one 2.2 had measurable fuel in its oil, and a 2013 diesel had a rising level at just 16,000 miles.

The filter needs to regenerate roughly every 200 miles, and economy drops sharply while it does, so lots of short trips from a cold start are exactly what it doesn't want. On a motorway or long A-road commute a diesel's fine, as long as the oil's at the right level and the seller can show the regeneration software update was done.

The 1.6 petrol is slow, and there's too little written about it to call it the dependable pick. Whichever engine you're looking at, a 2014 recall updated the engine software to stop piston rings sticking, which could otherwise cause blow-by and melt a piston. The recall doesn't say which engines it covered, so ask for proof it was carried out.

Very little is on record about the gearboxes, manual or automatic. One buyer of a brand-new ASX had a stiff gearchange that the dealer had for a fortnight and couldn't cure, so make sure every gear, reverse included, goes in cleanly on the test drive, and don't accept a seller telling you that's just how they are.

What should you check when viewing a used ASX?

On a diesel, pull the dipstick first: oil above the maximum mark, or oil that smells of diesel, means the filter hasn't been regenerating and fuel's been getting into the sump. Ask how the car's been used, look for regular oil changes in the history, and ask for paperwork showing the regeneration software update and the 2014 piston ring recall.

The brakes come next. A 2018 recall fixed poorly sealed boots on the rear handbrake caliper shafts of 2012 to 2016 cars, which let water rust the shafts until they stuck, so ask for proof it was done, though seized rear calipers have still turned up on some cars. One 2014 1.8 diesel 4x4 kept dragging its rear brakes by 66,000 miles, and a 2010 1.6 went through three caliper failures in 18 months. Check the handbrake holds on a slope, and feel each wheel for heat after the drive.

Get underneath and look at the fuel tank seams: one dealer-serviced 2012 car's tank rusted through and leaked at 34,000 miles. Check around the tailgate release catch for rust, which one owner of a commercial version found eating through, then lock it to make sure it latches, as a 2011 owner's tailgate wouldn't. Run the wipers too, since a 2018 recall dealt with corroding linkage joints that could leave the wipers dead.

On the road, feel for vibration through the car. One 2011 owner went through tyres trying to stop a drivetrain shake before a worn engine mount turned out to be the cause. Check the front tyres for wear on their outer shoulders, which one owner found badly worn at 8,500 miles, and see whether the windscreen mists up inside, a problem one new-car owner's dealer couldn't fix.

Paste the advert into the free check and it runs these against the listing, the MOT history and the DVLA record before you travel.

What does a used Mitsubishi ASX cost to run?