1999 Porsche 911: MOT pass rate and reliability

83.9% of 1999 Porsche 911s pass the MOT first time, measured across 1,164 DVSA tests on that model year alone. The average one had covered 94,453 miles.

How the 1999 compares

  • Against all Porsche 911s (89.6%, 46,586 tests): -5.7 points
  • Against all 1999 cars (68.6%): +15.3 points
  • National first-time pass rate, all cars and years: 77%

Every Porsche 911 model year

Pass rates fall as cars age, so the only fair comparison for a 1999 car is other cars of the same age. The full run for the Porsche 911:

Year Pass rate Tests Avg mileage
1990 90.6% 661 95,821
1991 91% 299 87,068
1992 94.2% 206 79,636
1993 90.9% 242 89,137
1994 89.2% 508 93,087
1995 88% 632 83,064
1996 90.3% 904 80,192
1997 89.5% 695 77,804
1998 84.5% 1,005 98,231
1999 83.9% 1,164 94,453
2000 83.6% 906 91,648
2001 85% 1,428 88,109
2002 83% 2,303 84,660
2003 83.5% 2,540 80,519
2004 85.6% 2,342 74,046
2005 86.8% 2,763 72,694
2006 87% 2,740 69,021
2007 88.1% 2,403 61,232
2008 90.1% 1,777 59,099
2009 90.6% 1,340 60,181
2010 91.6% 1,559 50,251
2011 92.8% 1,128 45,573
2012 92.1% 1,439 49,273
2013 93.9% 1,252 44,103
2014 94.4% 1,568 35,287
2015 95.3% 1,721 32,534
2016 96% 1,709 29,046
2017 94.9% 1,870 25,320
2018 95.1% 2,150 19,109
2019 95.6% 2,021 20,001
2020 96.5% 695 17,073

What this means if you are buying a 1999 911

The 1999 is a weaker year for this model, passing 5.7 points less often than the Porsche 911 average. Some of that is simply age, so compare it against the 1999 figure for all cars above rather than against newer examples. Check the exact car with the free MOT history checker before you buy, and run its VIN and mileage through our free VIN decoder and clocking check.

What a 27-year-old car fails on

A 1999 car is 27 years old now, and age drives the failure mix more than the badge does. Across all cars tested, these are the categories that actually cause failures:

  • Lights and electrical: 10.36% of all cars tested
  • Suspension: 8.65% of all cars tested
  • Tyres: 6.23% of all cars tested
  • Brakes: 6.1% of all cars tested
  • Visibility: wipers, washers, glass: 4.65% of all cars tested
  • Body, chassis and structure: 3.18% of all cars tested

That is above average, the point where suspension bushes, drop links and exhaust corrosion start showing up as advisories before they become failures. On a 1999 Porsche 911 the average at test was 94,453 miles, so treat anything far above that as a car that has worked harder than its peers, and anything far below as one worth checking for the faults that come from standing still.

The strongest year for this model is 2020 at 96.5%, and the weakest in our data is 2002 at 83%. That 13.5 point spread across the model's life is why comparing a 1999 car against a newer one tells you very little.

Nearby model years

All Porsche 911 MOT data · Every model