Servicing: what it covers and why intervals differ

Servicing and the MOT are different things and are routinely confused. The MOT is a legal roadworthiness test at a point in time. A service is preventative maintenance to a schedule set by the manufacturer. A car can pass an MOT while being badly overdue a service, and a freshly serviced car can fail an MOT.

What is typically covered

Schedules differ by manufacturer, but the shape is consistent.

An interim service concentrates on consumables and safety checks: engine oil and filter, fluid levels, tyre condition and pressures, brake inspection, lights, wipers, battery.

A full service adds the items on longer cycles — air filter, cabin filter, fuel filter on some engines, spark plugs where due, more thorough brake and suspension inspection, and a longer list of checks.

Major items sit on their own intervals and are the expensive ones: cambelt or timing chain, clutch, gearbox oil, brake fluid, coolant. These are scheduled by time or distance whichever comes first, and the time limit is the one people forget.

Why intervals vary so much

Because they are set by the manufacturer against that engine, and because usage matters. Short journeys, heavy loads, towing and stop-start city driving all age oil and filters faster than motorway miles. Many schedules therefore carry a “severe use” variant with shorter intervals, and a car used entirely for short urban trips is closer to that column than the standard one.

Diesel particulate filters are the clearest example: a diesel used exclusively for short cold runs may never reach the temperature needed to regenerate its filter, and the resulting problem is a maintenance failure rather than a fault.

Service history when buying

A stamped book is evidence, not proof. What raises its value:

• Invoices, not just stamps. They record what was actually done and by whom.
• Dates and mileages that line up with the MOT history and with each other.
• Continuity. A gap of three years in the middle is worth a question, and a plausible answer usually exists.
• The major items. Whether the cambelt has been done, when, and at what mileage is frequently the single most valuable line in the file.

Main dealer history is not automatically better than an independent specialist’s — a marque specialist with itemised invoices often tells you more than a generic stamp.

General information only. This is not legal, financial or technical advice, and rules change. Each page links to the official source — confirm the current position there before acting on it. This site sells nothing and is not a dealer, garage or broker.