Britain's most loved classic sports car, bar none
The MGB is the most accessible and practical classic British sports car on the UK market, with over half a million produced between 1962 and 1980. It remains the default entry point for classic car ownership, with usable examples starting from around £5,000 and the best chrome-bumper Mk1 Roadsters reaching £25,000. A massive club scene, abundant parts supply, and simple mechanics make it uniquely easy to own among classics of its era.
We track 5 known issues across the MG B range, including 1 rated as safety-critical. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a MG B? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
MK1 (1962–1967) — Engine options included the 1.8 BMC B-Series. Our database flags 4 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Structural corrosion compromising rigidity (£2,000–£5,000 to address).
MK2 (1967–1974) — Engine options included the 1.8 BMC B-Series. Our database flags 5 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Structural corrosion compromising rigidity (£2,000–£5,000 to address).
MK3 (1974–1980) — Engine options included the 1.8 BMC B-Series. Our database flags 5 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Structural corrosion compromising rigidity (£2,000–£5,000 to address).
The MGB monocoque construction uses steel prone to corrosion in structural areas including sills, floor pans, and bulkhead. Poor factory rustproofing and single-skin construction in critical areas make structural corrosion endemic on surviving examples. Areas of particular concern include inner and outer sills, rear wheel arch areas, and floor pan sections where water collects.
Severe structural corrosion renders the vehicle unsafe and unroadworthy. Professional restoration involving sill replacement, floor pan sections, and structural welding typically costs £3,000-£8,000 depending on extent. The car should not be driven if structural integrity is compromised.
Inspect the wheel arches, sills, jacking points and door bottoms carefully. Press gently on sills to check for soft spots. Look underneath for corrosion on structural components. Check the MOT history for corrosion-related advisories or failures.
The BMC B-Series engine in MGBs consistently fails MOT emissions tests at 199.3 times the fleet average, the highest failure rate in the MOT statistical data. This reflects the carburetted fuel system design, worn engine internals affecting combustion efficiency, and the challenge of maintaining correct mixture on aged SU carburettors. The issue affects all mileage ranges and has been worsening in recent MOT data.
The vehicle will fail MOT testing and cannot be legally driven on public roads until repaired. Professional carburettor setup and engine tuning typically resolves emissions issues. Severe cases may require engine internal work if compression is poor.
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.
MGB wheel bearings fail MOT testing for excessive play at 28.3 times the fleet average, with the trend worsening. The car uses traditional taper roller bearings front and rear that require periodic adjustment and lubrication. Age-related bearing wear combined with infrequent maintenance leads to dangerous wheel bearing play that affects steering precision and braking stability.
Excessive wheel bearing play creates dangerous driving conditions affecting steering control and braking performance. Severe play can lead to complete bearing collapse and wheel detachment. Professional bearing replacement and adjustment is required immediately.
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.
MGB suspension components fail MOT testing at 50.4 times the fleet average with a worsening trend. The car uses kingpin front suspension and leaf spring rear suspension with rubber bushes throughout that deteriorate with age. Trunnions, kingpins, and suspension arm bushes are particular failure points that affect handling safety and MOT compliance.
Worn suspension components compromise vehicle handling, steering precision, and braking stability. The vehicle will fail MOT testing and may become dangerous to drive. Professional suspension overhaul including bushes, kingpins, and trunnions is typically required.
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.
MGBs fitted with rack and pinion steering (from 1967) show steering rack gaiter failures at 69.7 times the fleet average. The rubber gaiters protecting the steering rack deteriorate with age, allowing dirt and moisture ingress that accelerates internal wear. This is primarily a later MGB issue as early cars used different steering systems.
Damaged gaiters allow contamination of steering rack internals leading to accelerated wear and eventual rack failure. The vehicle will fail MOT testing. Gaiter replacement is straightforward but delayed replacement may necessitate expensive rack overhaul or replacement.
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.
For the full breakdown of all 5 tracked issues with repair costs, see the MG B common problems page.
Based on 15k real DVSA MOT tests, the MG B fails more often than average on several items. The biggest outlier is light unit fault at 584x the fleet average, followed by emissions failure (438x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full MG B MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 3k miles) typically costs £80–£120 at an independent garage.
See the full MG B service schedule for every interval and cost breakdown.
The MG B has some well-documented weak points, including 1 safety-critical issue that demand careful checking. The right example, properly maintained, can still be a sound purchase — but cutting corners on the pre-purchase inspection is not advisable. The Mk1 Roadster (1962-1967) is the most desirable, with clean examples reaching £25,000. The Mk3 chrome-bumper cars (1972-1974) offer the best value among chrome-bumper Bs, starting from around £6,000. Late rubber-bumper cars (1976-1980) are cheapest but least loved. The 1967 MGB GT Special with overdrive is a particular sweet spot for the coupe.
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 MG B, 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 MG B issues. We are not affiliated with any source listed.