Smart Forfour problems (2014–2021)

We have documented 2 engines for the Smart Forfour; the 0.9 TCe has high or critical severity faults. None has a «Buy» verdict; the safest option is the 1.0 SCe (B4D), with a «With caution» verdict. Apart from the engine, the Smart Forfour (W453) has no chronic faults documented in the sources we were able to open; what there are is preventive recalls (handbrake, front hub carrier, rear seat backrest anchorage and selector cable) and the 12 V battery as a typical weak point on 2015 to 2017 cars according to ADAC statistics.

Among the 2 engines we have documented, none has a «Buy» verdict; the safest option is the 1.0 SCe (B4D), with a «With caution» verdict. No serious or systemic fault is documented in the reliability sources consulted (117 combined reviews across the three cars). It is worth checking the clutch, with a pattern of slipping or juddering when cold cited independently on the Dacia Sandero II, the Dacia Logan II and the Renault Twingo III, and, in the specific case of the Sandero II, keeping an eye on oil consumption.^[1][2][3]

Apart from the engine, the Smart Forfour (W453) has no chronic faults documented in the sources we were able to open; what there are is preventive recalls (handbrake, front hub carrier, rear seat backrest anchorage and selector cable) and the 12 V battery as a typical weak point on 2015 to 2017 cars according to ADAC statistics. The most important documented faults are: front left hub carrier with insufficient strength (2017 campaign) (suspension, critical severity), handbrake: the lever gains travel because of the cable adjustment and may not hold the car (brakes, high severity), rear seat backrest anchorage with insufficient strength in a frontal crash (airbags and safety, high severity) and gear selector bowden cable that can come loose and stop P engaging or disengaging (gearbox and clutch, high severity).^{[4][5][6][7][8]}

The most important by severity and frequency, on the engines we have documented, are: coolant leak at the thermostat housing (0.9 TCe, high severity), timing chain or tensioner failure (0.9 TCe, critical severity), clutch that slips or judders, especially when cold (1.0 SCe (B4D), medium severity), jerking, rough idle or warning light from sensors and ignition coils (1.0 SCe (B4D), medium severity) and turbocharger wear or failure (0.9 TCe, high severity).

According to our rating by year, the best are 2019 and 2018 (7.8/10); the worst rated is 2015 (6.4/10). Each year's rating counts only the engines sold that year and the faults that affect those units: open each year to see what changes.

Yes: we have documented 6 campaigns for the Smart Forfour, such as DVSA R/2017/252: incorrectly manufactured hub carrier (2017). Check with your VIN at the official service centre whether yours has been done.^[7]