1998 Porsche 911 (first used 1998) MOT pass rate, common failures & what to check

In 2025, 82.2% of Porsche 911s first used in 1998 passed their MOT first time, against 65.6% for all cars first used in 1998. Across 3,080 911 first tests from 2023 to 2025, the most common failure areas were lamps and electrical equipment, brakes and noise, emissions and leaks.

This page analyses first MOT tests for Porsche 911s first used in 1998 (all trims grouped): 2021 to 2025 for the pass-rate trend, and 2023 to 2025 for the failure and advisory analysis — plus what is worth checking before you buy one.

Data: DVSA anonymised MOT tests to December 2025 · Calculated by SortedCars · Updated October 2026

Passed first time, 2025
82.2%
of 982 first tests; all cars first used in 1998: 65.6%. Fixed-at-the-test counts as a fail
Tests analysed
3,080
first tests, 2023–2025; 982 in 2025
Clean pass, 2025
51.7%
of 982 first tests in 2025, passed with no advisory and no minor defect recorded
Typical mileage, tested in 2025
97,500
middle half: 73,000–122,000 miles; all cars first used in 1998: 98,000

How the 1998 Porsche 911 MOT pass rate has changed

Share of first tests passed in each year, 911s first used in 1998 against all cars first used in 1998 (any make or fuel; not adjusted for mileage, fuel or use). In 2025 the 911 figure was 16.6 points higher.

1998 911All cars first used in 1998
60%70%80%90%20212022202320242025Test year (first tests)All cars first used in 1998, test year 2021: 60.7%All cars first used in 1998, test year 2022: 62.4%All cars first used in 1998, test year 2023: 64%All cars first used in 1998, test year 2024: 64.9%All cars first used in 1998, test year 2025: 65.6%1998 911, test year 2021: 79.4%1998 911, test year 2022: 79.3%1998 911, test year 2023: 79.8%1998 911, test year 2024: 80.9%1998 911, test year 2025: 82.2%82.2%65.6%
View this chart as a table
Test year1998 911All cars first used 1998911 first tests
202179.4%60.7%1,172
202279.3%62.4%1,119
202379.8%64.0%1,059
202480.9%64.9%1,039
202582.2%65.6%982

Common 1998 Porsche 911 MOT failures

Share of the 587 failed first tests (2023–2025) with at least one failure in each area. A test can fail in more than one area, so the shares add up to more than 100%.

Lamps, reflectors and electrical equipment49.7%
Brakes26.2%
Noise, emissions and leaks22.1%
Suspension20.3%
Visibility15.5%
Tyres12.8%
Body, chassis, structure9.2%
Steering6.1%

Most common failure items

DVSA failure itemShare of failed first testsTests
Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits12.9%76
Headlamp: not working on dipped beam9.2%54
Horn: not working8.5%50

Item names are DVSA’s own wording. 2023–2025 combined.

What to check on a 1998 Porsche 911 before buying

The three areas where failed first tests most often had a fault, 2023–2025.

  1. Lamps and electrics. Ask someone to watch while you work the brake lights, indicators, sidelights, dipped and main beam, and the number-plate lamps.
  2. Brakes. Worth looking at the discs and pads through the wheel spokes for scoring and a worn lip, and noticing on the test drive whether the car pulls to one side or the pedal feels long.
  3. Engine and emissions. Worth checking that the engine warning light goes out after starting, looking for oil leaks under the car, and noticing any smoke from the exhaust.

Common 1998 Porsche 911 MOT advisories

Advisories are points the tester noted that did not fail the car. Most common on 1998 911s, as a share of all 3,080 first tests, 2023–2025.

DVSA advisory itemShare of first testsTests
Rigid brake pipes: corroded, covered in grease or other material12.7%390
Engine oil leaks: leak, but not excessive9.4%291
Brake discs: worn, pitted or scored, but not seriously weakened8.5%263
Tread depth: worn close to legal limit/worn on edge8.3%256
Tyre condition: slightly damaged/cracking or perishing4.7%145

Questions about the 1998 Porsche 911 MOT

What is the MOT pass rate of a 1998 Porsche 911?

In 2025, 82.2% of 911s first used in 1998 passed their MOT first time, against 65.6% for all cars first used in 1998. A car fixed during the test counts as a fail.

What does a 1998 911 most often fail its MOT on?

Lamps and electrical equipment (in 49.7% of failed first tests, 2023–2025), brakes (26.2%) and noise, emissions and leaks (22.1%). The single most common item was “Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits” (12.9%).

How often does a 1998 Porsche 911 fail its MOT?

In 2025, 17.8% of first tests on 911s first used in 1998 did not pass first time: 15.6% failed, and a further 2.2% had a fault fixed during the test (counted as a fail here). Across 2023–2025, 587 of 3,080 first tests did not pass first time.

What are the most common 1998 Porsche 911 MOT advisories?

“Rigid brake pipes: corroded, covered in grease or other material” (on 12.7% of first tests, 2023–2025), “Engine oil leaks: leak, but not excessive” (9.4%), “Brake discs: worn, pitted or scored, but not seriously weakened” (8.5%), “Tread depth: worn close to legal limit/worn on edge” (8.3%) and “Tyre condition: slightly damaged/cracking or perishing” (4.7%).

Is a 1998 Porsche 911 reliable?

An MOT pass rate shows what failed at the test, not how reliable a car is. For this group of cars the first-time pass rate went from 79.4% in 2021 to 82.2% in 2025. For one particular car, its own MOT history matters more than the average.

Other cars first used in 1998

The most-tested cars from the same year. Each page uses the same method.

1998 Volkswagen Transporter MOT statistics · 1998 Land Rover Defender MOT statistics · 1998 Mazda MX-5 MOT statistics · 1998 BMW Z3 MOT statistics · 1998 BMW 3 Series MOT statistics

How the 1998 Porsche 911 MOT data is calculated

Every number on this page is calculated by SortedCars from DVSA’s anonymised MOT test data for Great Britain, 2021–2025. “1998 911” means a Porsche 911 whose date of first use falls in 1998 (R and S plates), all trims grouped. Class 4 vehicles, first tests only — retests are not counted. Pass rate = passed ÷ all first tests; a car with a fault fixed during the test (PRS) counts as a fail. Our national first-test pass rate matches DVSA’s published figure (table DVSA/MOT/01) to within 0.04 points in every year. Clean pass = passed with no advisory and no minor defect recorded. Mileage is the reading recorded at the test. Comparisons are with all cars first used in 1998, any make or fuel, and are not adjusted for mileage, fuel or use. Failure and advisory item names are DVSA’s own wording. No figure is shown for fewer than 500 tests; an item is shown only if it appears on at least 50 tests and 1% of the base. Pass rates describe a group of cars, not one car: a well-kept example can pass and a neglected one can fail. This page is general information, not advice about any particular vehicle; always have a used car inspected before you buy. SortedCars is not affiliated with or endorsed by DVSA. You can check any car’s MOT history free on the official service: gov.uk/check-mot-history. Contains public sector information licensed under the Open Government Licence v3.0.