Four seats squeezed into the tightest parking spot
The Smart ForFour is a rear-engined city car built on the same platform as the Renault Twingo, aimed at urban drivers who want four seats in the smallest possible footprint. It sits below mainstream superminis like the VW Up and Hyundai i10, targeting city dwellers who need occasional rear-seat access. The second generation (2014-2019) shares its Renault-sourced mechanicals and improved dramatically over the troubled first generation.
We track 5 known issues across the Smart (mcc) Forfour range, with 3 classified as significant. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Smart (mcc) Forfour? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
W454 (2004–2006) — Petrol options included the 1.0 Suprex, 1.1 Mitsubishi, 1.3 Mitsubishi, 1.5 Mitsubishi, with 1.5 DCI on the diesel side. We track 3 known issues on this generation, with 2 classified as significant. The most significant concern is Suspension joint wear (£300–£600 to address).
W453 (2014–2019) — Engine options included the 0.9 Turbo, 1.0 Naturally Aspirated. We track 2 known issues on this generation, with 1 classified as significant. The most significant concern is Emissions system failure (£200–£600 to address).
The 0.9L turbocharged and 1.0L naturally aspirated engines in W453 ForFour show exceptionally high MOT failure rates for emissions-related defects. The turbo variant appears particularly affected, likely due to higher combustion temperatures and boost system complexity affecting sensor operation and exhaust gas recirculation.
Failed MOT test requiring immediate repair before the vehicle can be driven legally. Typical fixes involve lambda sensor replacement, catalytic converter cleaning or replacement, or exhaust system repairs. Total repair costs range from £200-£800 depending on the specific fault.
Check for any engine warning lights on the dashboard. Ask about the car's MOT emissions history — repeated failures suggest underlying issues. A pre-purchase diagnostic scan is especially worthwhile to check for stored emissions fault codes.
First-generation ForFour models show MOT failure rates nearly 10 times the fleet average for suspension component wear, particularly affecting ball joint dust covers and suspension bushes. The shared platform with Mitsubishi Colt means parts wear patterns are similar. Worn suspension components affect handling safety and will cause MOT failure.
MOT failure and compromised handling safety. Worn ball joints can separate causing loss of steering control. Typical repair involves replacement of affected joints, bushes and alignment check. Labour-intensive due to subframe removal requirements.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
MOT data shows first-generation ForFour models fail for wheel bearing roughness at over 12 times the fleet average. The Mitsubishi-sourced front wheel bearing assemblies appear prone to premature wear, particularly on higher mileage examples. Failed bearings create safety risks and will cause MOT failure.
MOT failure and potential wheel collapse if bearing completely fails. Worn bearings affect braking efficiency and steering precision. Replacement requires hub assembly removal and is moderately labour-intensive.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
MOT data shows W454 ForFour models fail at nearly 13 times the fleet average for steering rack gaiter and ball joint dust cover deterioration. These rubber protective covers prevent dirt and water ingress to steering components. While not immediately dangerous, failed gaiters allow contamination that accelerates wear of expensive steering components.
MOT advisory initially, becoming a failure if deterioration is severe. Failed gaiters allow dirt and water to contaminate steering rack internals, leading to expensive rack replacement if left unrepaired. Gaiter replacement is relatively inexpensive preventative maintenance.
During the test drive, check the steering for excessive play, vibration or pulling to one side. Listen for groaning or whining when turning the wheel at low speed. Power steering fluid level and condition should be checked on hydraulic systems.
MOT data shows W453 models fail at over 16 times the fleet average for noise suppression system security, indicating exhaust mounting and silencer problems. The compact design means exhaust systems run close to bodywork and are subject to heat cycling stress. Insecure or damaged silencers cause excessive noise and MOT failure.
MOT failure for excessive noise or insecure mounting. Damaged exhaust systems can affect emissions performance and in extreme cases allow toxic gases to enter the cabin. Repair typically involves silencer replacement or exhaust mounting repair.
Check for any engine warning lights on the dashboard. Ask about the car's MOT emissions history — repeated failures suggest underlying issues. A pre-purchase diagnostic scan is especially worthwhile to check for stored emissions fault codes.
For the full breakdown of all 5 tracked issues with repair costs, see the Smart (mcc) Forfour common problems page.
Based on 119k real DVSA MOT tests, the Smart (mcc) Forfour fails more often than average on several items. The biggest outlier is body panel damage at 95x the fleet average, followed by stop lamp with a multiple light source up to 1/... (55x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full Smart (mcc) Forfour MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 10k miles) typically costs £80–£120 at an independent garage.
See the full Smart (mcc) Forfour service schedule for every interval and cost breakdown.
The Smart (mcc) Forfour is a solid choice on the used market, though not without its quirks. The issues we track are well-understood and largely avoidable if you know what to look for. A thorough inspection and complete service history go a long way. 2015-2019 second-generation models are vastly superior to the first generation, with Renault-sourced engines providing much better reliability. The 2016-2017 petrol models hit the sweet spot with improved software stability and lower maintenance frequency compared to launch-year cars.
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific Smart (mcc) Forfour, we cross-reference the exact variant, engine and age against our database of 5 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 5 known Smart (mcc) Forfour issues. We are not affiliated with any source listed.