A significant improvement can be made to the performance of the Mercedes 126 headlamps by replacing the DOT certified units with genuine European lighthouses.
Especially in the case of early (first-generation) cars 126 before 1986, the DOT-approved lights for the US market were terribly inefficient compared to Bosch headlights installed in Europe. The pun is barely excusable, but the difference in light output is almost night and day. One can only assume that this lamentable situation was the result of federal regulations drafted at the request of certain Presidents of Congress who protected the commercial interests of the companies in their districts. The rules have increased the demand for traditional sealed beam headlights at the expense of road safety.
The original H-4 "Euro" headlights are still available at Bosch but are very expensive. Fortunately, the right units used can be found both domestically and with European sellers. And there are after-sales copies of companies like Depo that seem almost as good (but are not as well done). Glass lenses can be purchased separately for damage, but internal parts are no longer sold separately.
In addition to a reflector and a superior lens design, Euro lamps offer the Mercedes owner the flexibility to easily change the light bulb. whole unit. And the performance of the lamps can be further improved with bulbs with high efficiency or surge. That said, one should be wary of imposing an excessive load on the wires at the lights. While Mercedes wiring is better than most, there comes a time when excessive heat could damage the wiring and voltage drops would hinder performance. These problems can be avoided by using relays. But for most drivers, the standard European bulb output will be more than enough.
European headlights also offer a city light – a small 4 watt bulb that can easily be wired to the existing circuit for the sides. markers, providing additional identification. And for gadget lovers, there's a vacuum-controlled height adjustment feature that can be used to adjust the lights inside the car when carrying heavy loads. Some understanding of the car's vacuum circuits is needed for this modification, but it's not difficult.