The best bulbs have Philips or Osram on the baseplate. The former has the edge, as subsidiary Narva supplied Halfords' Brilliance. But the results were close whether you want blue, +30, +50, H1 or H7.

To find out, we return to the big-selling H7 single-filament bulb found in many new cars with separate dip and main beam lights. And for the first time we also look at H1 – the original halogen ...

After around four years, Osram is replacing its LED retrofit lamps, which can be used instead of H7 bulbs. The next generation of H7 LEDs, which are already road-approved for many vehicles, offers ...