Used Mercedes-Benz B-Class review and buying guide (2004 to present): which one to buy and what to check

Which used Mercedes-Benz B-Class should you buy?

A manual is the lower-risk B-Class in either generation, because both automatics carry known faults, though there's little on record about the manual either way. On the 2013 to 2018 car, the B180, B200 and B250 petrols (M270) carry a High timing chain fault too, so a diesel's the lesser risk there. That car is covered up to 2017 by the airbag clock spring recall, so don't buy one without paperwork showing the work's been done.

The first B-Class, sold from 2004 to 2012, is a risky buy as an automatic. Its Autotronic CVT has a high-rated fault where the gearbox's own control unit fails between 27,000 and 70,000 miles, and owners have reported failures at 30,000, 43,000 and 62,000 miles. A manual one dodges that, but water getting into the boot floor and battery compartment has been reported by several owners, so it still needs a careful look.

Cars from 2019 onwards are the newest shape and there isn't much on record about them yet. Some 2019 cars had recalls for transmission software that could stop the car selecting drive or reverse, radar sensor software, and a high beam that the lever couldn't always switch off, all fixed with software updates. The automatic's been called hesitant, and where it's the 7G-DCT, its clutch pack fault on file runs to 2023. One owner of a 2019 B180 had a front clunk and surging when pulling away from cold.

Which B-Class engines and gearboxes are the safe choices?

Neither automatic is a safe choice, so a manual's the lower risk in both generations, though the records hold nothing on the manual either way. The 2004 to 2012 car's CVT is the one to avoid outright: its sealed control unit loses its speed sensor circuits, the dash lights a gearbox warning and the car drops into limp mode. Its manual mode also holds whichever ratio you pick until you change it, which catches out drivers who don't know.

The 7G-DCT dual-clutch automatic in the 2013 to 2018 car carries a medium-rated fault between 50,000 and 100,000 miles as its wet clutch packs wear and its control unit fails, and owners have reported trouble far sooner. One had a clutch fail at 18,000 miles with a loud judder, a B180d at 18,000 miles was sluggish from standstill, and a 2016 B200 petrol was reported surging on the change from first to second at low speed, which a software reset didn't cure.

The 2013 to 2018 car's 1.6 and 2.0 turbo petrols (M270) are the engines to be wary of: their hydraulic tensioners leak and the timing chain stretches, rattling on a cold start, and if it's ignored the chain can jump a tooth. There's no set replacement interval for it, and the cam phasers wear from around 60,000 to 80,000 km, giving a tick from cold.

The first-generation diesels drone when you accelerate, idle at about 700 rpm with the whole car shaking, and send vibration through the accelerator pedal on right-hand-drive cars. Used for lots of short trips from cold, their glowplugs corrode and stick in the head through condensation, so a diesel that's only ever done the school run isn't the one to buy. On the later car, the Renault-sourced 1.5 diesel has a cambelt due every 60,000 miles or 5 years, whichever comes sooner.

What should you check when viewing a used B-Class?

Lift the boot floor on a 2004 to 2012 car and look in the spare wheel well for water. Broken or badly sealed vents behind the rear bumper, which let air out of the cabin, are how it gets in, and one owner paid £1,200 to have the area stripped and new vents fitted. Blocked bulkhead vent wells can flood the battery compartment and soak the pollen filter too.

On a 2013 to 2018 petrol, a metallic rattle for several seconds from cold means the chain's stretched. On an automatic, drive it from cold and in slow traffic. A CVT that flashes a workshop warning, drops into limp mode or sticks in one ratio has the known fault. A 7G-DCT that judders or lurches pulling away, bangs when you select P, N or R, or shifts harshly in the low gears is showing the wear in its clutch packs or control unit that the known fault describes.

An airbag warning light on a B-Class built from 2011 to 2017 points to the clock spring fault, which can short and fire the driver's airbag with no warning, so ask for proof the recall work's done. On a 2013 to 2018 car, also ask about the recalls for the brake booster vacuum line and the front passenger airbag, and the one on 2014 cars that checked the passenger airbag's fuses.

Two owners had a 'Pre-safe disabled' warning arrive with a sudden loss of power, and software updates didn't cure it for good on one of them, so treat that message on the dash as a reason to pass. On a first-generation car, have the driveshafts checked, since they start giving trouble at around five years old, and make sure the air-con blows cold.

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

Is a used Mercedes-Benz B-Class W169 / W245 (2004 to 2012) a good buy?

It's worth buying only as a manual, and that rests on the automatic's record rather than the manual's, which has little on file either way. The Autotronic CVT has a high-rated fault that shows up between 27,000 and 70,000 miles, owners have reported failures at 30,000, 43,000 and 62,000 miles, and one reported valve bodies giving out at around 70,000 miles on a six-year-old car, so an automatic without evidence of gearbox work is a gamble.

The CVT that failed at 30,000 miles had a full service history, and its fault was traced to the secondary speed sensor, so a stamped book doesn't prove the gearbox is healthy. Drive any automatic until it's fully warm and watch for the workshop warning, a sudden loss of drive or the car staying stuck in one ratio.

Away from the gearbox, water gets in through the rear cabin vents and blocked vent wells, and the water pump's retaining bolts can work loose, with the engine having to come out to reach them. Driveshafts start causing trouble at around five years. One owner of a 2011 B200 had the ignition switch module fail twice, leaving the car dead and refusing to start. A 2011 or 2012 car also falls inside the clock spring airbag recall's years, so ask for proof that work's been done.

Which Mercedes-Benz B-Class W176 / W246 / C117 / X156 (2013 to 2018) is the one to buy?

Go for a manual diesel, because this B-Class's 7G-DCT automatic has a medium-rated fault between 50,000 and 100,000 miles, with owners reporting clutch failure, surging, crunching and failure to engage drive, some at just 18,000 miles, and the B180, B200 and B250 petrols (M270) carry a known fault for stretching their timing chains. There's little on record about the manual itself. Cars up to 2017 are also covered by the clock spring recall, so check the paperwork shows it's done.

Other recalls on this generation replaced a brake booster vacuum line whose fitting could fail and leave you pressing much harder on the pedal, swapped front passenger airbags whose igniters could stop them deploying, and added a fuse to the starter feed to prevent overheating if a seized engine is cranked over and over. It rides firmly on every surface and the steering's response isn't consistent, so take a long test drive on poor roads.

One owner of a 2013 B180 CDI needed a new engine when a main bearing turned noisy before 23,000 miles, so listen for knocking from low down in the engine. The electric B250e has two owner reports against it: one had a workshop warning at 68,000 miles traced to the traction battery, and another's 12-volt battery went flat on overnight charge because a charging relay kept clicking, leaving it unable to start.

What does a used Mercedes-Benz B-Class cost to run?

What do B-Class owners like about them?

There's plenty of room in the front and the back of the 2013 to 2018 car, and the boot's big to start with. Slide the rear bench forward and it grows further, so you can swap some rear legroom for luggage when the load needs it.

Every engine in the 2013 to 2018 car is frugal, the most powerful ones included, so picking a stronger version doesn't mean giving up economy. The car that arrived in 2019 is a much better looking thing than either of the two B-Class shapes that came before it.

• The B-Class achieved the top position for customer satisfaction in the MPV sector in the 2010 JD Power Survey.
• The B-Class provides ample cabin room for all occupants, complemented by a spacious boot expandable via a sliding rear seat.
• Every B-Class model comes equipped with extensive safety features, including emergency braking as a standard inclusion.
• All B-Class engines are economical, with even the most powerful versions producing low CO2 emissions.
• The B220 CDI impressed with its power and the smooth shifting of the new seven-speed dual-clutch transmission.