The A23 counts in engine hours rather than miles
London Road through Norbury is both the high street and a red route, which is why it moves the way it does. Buses pulling in and out, traffic lights, loading restrictions and the queue building towards Thornton Heath Pond mean a two-mile trip can occupy twenty minutes of engine running. Oil does not care about distance. It ages through heat cycles and running time, so a Norbury car can use up its oil at twice the rate of an identical car doing the same mileage on open roads.
That shows up clearly on cars with a variable oil interval. The counter works from temperature, load and how long the engine runs, and drivers who spend their week on the A23 often find it falling much faster than the odometer implies. Away from the main road the picture does not improve much: the 20mph streets around the Norbury Cottage Garden Estate and the links across to Pollards Hill are narrow, parked on both sides and full of very short journeys.
If you have recently bought a car with no paperwork, this is the job that gives you a known starting point. We change the oil and filter, record the date, mileage, grade and filter number on your invoice, and from then on you can judge consumption and intervals against something real. If there is a particulate filter in the exhaust, the refill is a low-ash grade that carries your engine's approval rather than whatever is closest on viscosity.
The run down takes you past Thornton Heath Pond and the Lombard roundabout, then west across Mitcham Common on the A236 before a left turn onto the A237 brings you into Hackbridge. It is a straightforward drive outside peak hours and a slow one during them, so it pays to book mid-morning. You will have a written price before we lift a spanner.