Typically,
motorists will only replace a headlight bulb that has burned out or
is failing. However, replacing just one failed bulb can result in an
unbalanced or unpredictable headlight beam, which presents a
potential safety risk. From the driver’s perspective, the road
ahead will not be properly lit, and the driver will not get the full
benefit of the vehicle’s headlights as the car maker originally
intended.
From
the oncoming driver’s perspective, an uneven headlamp beam can
create an equally risky safety issue. The oncoming car will be harder
to see and difficult to position on the road. It could also be
confused with a single headlight vehicle such as a motorcycle.
Replacing
important auto parts in pairs is a common sense idea. Professional
automotive technicians and driving safety advocates alike
consistently recommend that tires, brakes, shocks, and wiper blades
should be replaced in pairs to make sure the vehicle is properly
balanced and functioning safely. Lighting is no different and equally
as important to driver safety.
Why
replace headlight bulbs when they get old?
Many
drivers will only replace a bulb that has completely failed, but for
maximum driving safety, an aging bulb should replaced before it burns
out. The filament of any halogen headlight bulb ages with use, time,
and exposure to the elements. As a result, the bulb’s light output
deteriorates. At the end of their typical service life, headlight
bulbs project less light, and that reduces the driver’s nighttime
visibility.
For
example, a new headlight bulb that can typically project a 240-foot
beam will only be able to deliver a 160-foot beam after three years.
That’s potentially a whopping 33% percent less light and a critical
safety concern.
Changing
bulbs in pairs also makes good sense from an efficiency point of
view. You only have to go to the shop once and you reduce the risk of
the other headlight bulb failing while you’re on the road.