Standard 2.2w tungsten screw, 12v LED and wide-angle LED screw, 4w tungsten bayonet, and 6w halogen bayonet bulbs compared.

Standard and LED bulbs shining onto a board, showing the very much whiter light of the LEDs

Side-by-side comparison of a single Maplin oval high-brightness, wide-angle white LED with a standard 12v 2.2w incandescent bulb. Although whiter and more intense than the incandescent here, in the fuel gauge it was noticeably less bright, so much so it wasn't worth a photo.

The following images are as I see them when driving and so are not intended to be bright enough to clearly read them, they just show the comparison between standard and LED bulbs.

Fuel gauge with incandescent (left), standard LED (centre) and wide-angle LED (right) bulbs. Very little difference in legibility between the three, although the LED bulbs give a whiter glow.

Tach with incandescent (left), standard LED (centre) and wide-angle LED (right) bulbs. Both LEDs give a significant improvement in legibility over the incandescent, with the standard LED again being noticeably better than the wide-angle. To me the whiter light of the LEDs also gives a more attractive appearance over the yellow of the incandescent.