The Mercedes-Benz R320 front fog light uses H11 or H7 bulb sizes, while the rear fog light requires a P21W bulb size. The replacement chart covers 2007 to 2009 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz R320 front fog light uses two different bulb types across its model years: the H7 for 2007-2008 and the H11 for 2009. These two bulb types are not interchangeable, as they use different bases, making year-specific fitment verification necessary before replacement.
The H7 bulb, used in the R320 front fog lights for 2007-2008, is a single-filament halogen bulb operating at 12V and 55W. It uses a PX26d base and meets ECE standards, with approval also extended to the US and Japan.
The H11 bulb, fitted to the 2009 R320 front fog light, is likewise a single-filament halogen bulb rated at 12V and 55W. However, it uses a PGJ19-2 base, which is physically distinct from the PX26d base of the H7.
Although the H7 and H11 share identical voltage and wattage ratings of 12V and 55W, their base types differ. This means electrical compatibility does not translate to physical fitment compatibility between the two bulb types.
The P21W bulb is used in the R320 rear fog light across all three model years covered: 2007, 2008, and 2009. This consistent fitment means a single bulb type serves the rear fog light position throughout the entire specification range.
The P21W is a single-filament signalling bulb rated at 12V and 21W. It uses a BA15s bayonet base, which is a single-contact bayonet fitting commonly associated with signalling and auxiliary lighting applications.
At 21W, the P21W operates at significantly lower wattage than the H7 and H11 halogen bulbs used in the front fog lights. This reflects the different functional role of rear fog lighting compared to forward-projecting fog illumination.
All three bulb types specified for the R320, the H7, H11, and P21W, conform to ECE standards, indicating suitability for European and worldwide markets. The H7 and H11 carry additional approval for the US market, while the H7 is also approved in Japan.