Norton 99 Reliability, MOT Pass Rate & Common Faults
Free Norton 99 car check
Is the Norton 99 reliable? We analysed 786 real MOT tests across 141 vehicles to find out.
Got a specific Norton 99? Enter the reg for a free check:
The Norton 99 is above average for reliability based on real UK MOT data. Common problems include drive chain excessively tight, throttle operating incorrectly slide is sticking and suspension has inadequate damping effect.. Here's everything you need to know before buying a used Norton 99.
Norton 99 Number Plates
Number plates registered to a Norton 99. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
Norton 99 MOT Pass Rate by Year
How likely is a Norton 99 to pass its MOT? Here's the pass rate for each registration year, newest first.
Norton 99 Problems — What Goes Wrong?
The most common reasons a Norton 99 fails its MOT, ranked by how often they occur. Check for these problems before you buy.
Norton 99 Common Faults & Problems
These are the most common serious faults found on Norton 99 models during MOT testing — flagged as dangerous or major failures that need immediate attention.
Norton 99 Mileage — What's Normal?
How many miles does a typical Norton 99 owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
Norton 99 MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the Norton 99 year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 1962 | 60 | 90.0% | 10,186 | 14,528 | 34,335 |
| 1961 | 69 | 97.1% | 13,171 | 49,134 | 60,634 |
| 1960 | 156 | 96.2% | 6,150 | 9,276 | 28,119 |
| 1959 | 140 | 91.4% | 3,569 | 18,621 | 49,956 |
| 1958 | 86 | 93.0% | 12,572 | 31,754 | 53,796 |
| 1957 | 52 | 86.5% | 682 | 1,047 | 14,805 |
How Long Does a Norton 99 Last?
Based on 141 Norton 99 vehicles on UK roads.
Norton 99 Mileage Distribution
Total mileage recorded across all Norton 99 MOT tests. If the car you're looking at is above the 75th percentile, it's done more miles than most.
Best Year to Buy a Used Norton 99
Based on MOT pass rates across all registration years with sufficient test data.
97.1% MOT pass rate from 69 tests
86.5% MOT pass rate from 52 tests
The best year to buy a used Norton 99 is 1961, which has the highest MOT pass rate at 97.1% across 69 tests. The 1957 model year has the lowest pass rate at 86.5% — if you're looking at one from that year, budget for potential repairs and get a thorough pre-purchase inspection.
How Does the Norton 99 Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| Norton 99 THIS CAR | 93.8% | 786 | 12,565 mi | 69 yrs |
| Norton Commando | 91.4% | 13,398 | 18,484 mi | 58 yrs |
| Norton Dominator | 93.2% | 4,068 | 8,674 mi | 72 yrs |
| Norton Commander | 92.3% | 2,220 | 26,431 mi | 55 yrs |
| Suzuki Gsxs 750 Z AM1 | 89.7% | 906 | 4,912 mi | — yrs |
Compared to the Norton Commando (91.4% pass rate) and the Norton Dominator (93.2% pass rate), the Norton 99 outperforms both on MOT reliability.
Found a Norton 99 you like?
Run a full vehicle history check on the specific car. See finance, stolen, write-off, mileage and MOT data for that exact vehicle.
Check a specific Norton 99Should you buy a used Norton 99?
The Norton 99 has an overall MOT pass rate of 93.8% across 786 real MOT tests — comfortably above the UK average, which puts it among the more reliable models on UK roads.
The most common problems on the Norton 99 are drive chain excessively tight (2 recorded failures), throttle operating incorrectly slide is sticking (1), and suspension has inadequate damping effect. (1). These are the faults most likely to cause an MOT failure on this model, so check for them carefully on any test drive or pre-purchase inspection. Many are wear-and-tear items that can be budgeted for, but a car that's already failing on multiple fronts may signal neglected maintenance.
On the safety side, the most frequently flagged dangerous fault is tyre tread depth is below minimum requirements of 1.0mm. Dangerous faults cause an immediate MOT failure and mean the vehicle is not roadworthy until repaired. If you're viewing a Norton 99 with an expired or recently passed MOT, ask the seller whether any dangerous faults were found and fixed during the last test.
A typical Norton 99 owner drives around 238 miles per year. If the car you're looking at is significantly above this, expect more wear on suspension, brakes and tyres. If it's well below, the vehicle may have been sitting unused — check for perished rubber, corroded discs and stale fluids.
In terms of longevity, most Norton 99 models stay on UK roads for around 69 years — a strong showing that suggests solid build quality and readily available parts. If you're buying one that's already approaching that window, the data suggests it has plenty of life left provided it's been maintained.
Before committing to a purchase, we recommend running a full vehicle history check on the specific car. This will reveal any outstanding finance, stolen markers, write-off history and mileage discrepancies that the seller may not disclose — and that the MOT data alone can't tell you.