How we source our data

A wrong bulb means a wasted trip to the parts store, so we hold every answer on this site to the same simple rules.

1. The owner’s manual comes first

Most of our bulb sizes come straight from the carmaker’s owner’s manual for that exact model year. Each one links to the page it came from, so you can check it yourself. Where the carmaker no longer hosts an old manual, we use an unchanged archived copy of the carmaker’s own file.

2. Two sources when the manual is silent

Some manuals don’t list bulb sizes. For those years we only show a bulb when two independent sources agree on it, for example a bulb maker’s vehicle application catalogue and the carmaker’s own parts catalogue. We test each of these rules against vehicles whose manual does list the bulb, and only use rules that match the manual at least 95% of the time. These answers carry a “Two sources” label.

3. No guessing

If we can’t confirm a year, we mark it as not verified instead of filling it in from a neighbouring year. When a year has different bulbs depending on trim or headlight type, we list each one with its condition.

Before you buy

Bulb sizes can change mid-year or between trims. The quickest check is the size printed on the base of the old bulb. If you spot a mistake, we want to hear about it.