Proton Sl Reliability, MOT Pass Rate & Common Faults
Free Proton Sl car check
Is the Proton Sl reliable? We analysed 1,218 real MOT tests across 302 vehicles to find out.
Got a specific Proton Sl? Enter the reg for a free check:
The Proton Sl is about average for reliability based on real UK MOT data. Common problems include tyre tread depth below requirements of 1.6mm, constant velocity joint gaiter split and brake pipe excessively corroded. Here's everything you need to know before buying a used Proton Sl.
Proton Sl Number Plates
Number plates registered to a Proton Sl. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
Proton Sl MOT Pass Rate by Year
How likely is a Proton Sl to pass its MOT? Here's the pass rate for each registration year, newest first.
Proton Sl Problems — What Goes Wrong?
The most common reasons a Proton Sl fails its MOT, ranked by how often they occur. Check for these problems before you buy.
Proton Sl Mileage — What's Normal?
How many miles does a typical Proton Sl owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
Proton Sl MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the Proton Sl year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 1996 | 369 | 72.6% | 57,982 | 72,781 | 89,728 |
| 1995 | 505 | 69.9% | 58,655 | 72,791 | 91,130 |
| 1994 | 342 | 68.4% | 62,077 | 79,050 | 96,813 |
How Long Does a Proton Sl Last?
Based on 302 Proton Sl vehicles on UK roads.
Proton Sl Mileage Distribution
Total mileage recorded across all Proton Sl 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 Proton Sl
Based on MOT pass rates across all registration years with sufficient test data.
72.6% MOT pass rate from 369 tests
68.4% MOT pass rate from 342 tests
The best year to buy a used Proton Sl is 1996, which has the highest MOT pass rate at 72.6% across 369 tests. The 1994 model year has the lowest pass rate at 68.4% — if you're looking at one from that year, budget for potential repairs and get a thorough pre-purchase inspection.
How Does the Proton Sl Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| Proton Sl THIS CAR | 70.3% | 1,218 | 74,208 mi | 32 yrs |
| Proton Persona | 66% | 104,196 | 68,588 mi | 32 yrs |
| Proton GEN-2 | 70.5% | 59,272 | 46,580 mi | 22 yrs |
| Proton Wira | 70.1% | 57,151 | 47,970 mi | 26 yrs |
| Toyota Corolla Verso T2 D-4D | 83% | 458 | 149,838 mi | — yrs |
Compared to the Proton Persona (66.0% pass rate) and the Proton GEN-2 (70.5% pass rate), the Proton Sl sits in the middle of the pack on MOT reliability.
Found a Proton Sl 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 Proton SlShould you buy a used Proton Sl?
The Proton Sl has an overall MOT pass rate of 70.3% across 1,218 real MOT tests — roughly in line with the UK average.
The most common problems on the Proton Sl are tyre tread depth below requirements of 1.6mm (113 recorded failures), constant velocity joint gaiter split (94), and brake pipe excessively corroded (81). 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.
A typical Proton Sl owner drives around 4,568 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 Proton Sl models stay on UK roads for around 32 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.