Correct headlight aim important for vehicle safety

BY Jim Kerr. Jun 10 04:00 am

Question: Is there any way to measure if headlights are putting out sufficient light to match Federal Motor Vehicle Safety Standard Requirements and Canada Motor Vehicle Safety Standards?

Answer: This is a great question, but not a simple one to answer. There are light meters available that measure the candlepower output of lights, but unless you are willing to spend several thousands of dollars, the lower-priced tools are more of a comparison tool rather than an actual candlepower number.

Even with the best tools, the position of the tool in the light beam is critical to measuring accurately. Being off even a millimetre from the brightest spot will change the readings.

A more practical way of measuring light output is to place an object in front of the vehicle on a dark night and see how far the object can be moved away and still be seen. In the past, one of the U. S. tests was to see if the object could be illuminated at a distance of 36 metres (118 feet). This isn’t very far, and under the stopping distance of most vehicles from 100 kilometres per hour. Again, this is a comparison test but does reveal how far you can see with your headlights.

The regulations concerning lighting systems haven’t kept pace with technology. Much of the regulations are from the 1980s and there are now many types of headlamps, from older sealed beams, to the modular LED systems we are now finding on new vehicles. As for regulations, a single filament type of headlamp unit is limited to a 55-watt rating on the upper beam bulb, while a dual filament lamp could have a 43-watt rating on the upper and 65-watt rating on the lower filaments.

For a different modular unit, it could be 70 watts on the upper beam and a 60-watt rating on the lower beam. The lamp units or bulbs must have a DOT identification, and in many jurisdictions, the aftermarket “blue” tinted bulbs are illegal.

Even to those in the industry, it is a complex and confusing issue.

The design of the lens and reflector plays an important part in the light produced. Recently, in the U. S., the Insurance Institute for Highway Safety (IIHS) tested the headlight output of many vehicles. The Prius V with LED headlamps came out on top, while several luxury vehicles had poor ratings.

Correct headlight aim is one of the most important considerations for nighttime driving visibility and to prevent glare for other drivers. The condition of any plastic cover or lens on the headlight modules is also important. Yellowed or scratched plastic lens can be polished with kits available from auto supply stores and can make a remarkable difference. Professional polishing by an automobile detail shop or auto body shop can often make even badly discoloured units look clear again.

Question: After a recent trip to my garage for minor work on my 2007 Honda CRV LX, I was told my next visit would cost more for “valve re-timing.” They stated my model has no automatic valve timing and similar vehicles have had to have engine replacement due to cams misfiring and damaging engine walls. I’d appreciate your comments. — Russel

Answer: The 2.4 Litre engine in your CRV does have variable camshaft timing as a feature. The camshaft sprocket is moved by oil pressure in relation to the camshaft position to advance or retard the timing of the valve sequences. This is done to improve performance and fuel economy.

From your comments, it sounds like the variable camshaft timing on your CRV is not working correctly. I would have expected this to turn on the check engine light.

Some units will make noticeable knocking sounds on start up or when cold, and this can also be traced back to variable camshaft timing units not working correctly. I haven’t seen any that have caused damage to engine cylinder walls, but they can cause rough running, stalling, knocking sounds and poor fuel economy or performance.

If you are having no driveability symptoms and the check engine light is not illuminated on the dashboard with a code for variable camshaft timing, then you do not need to have “valve re-timing” – whatever that means. Perhaps they are referring to fixing a problem with the variable cam timing.

I would suggest you talk with your garage and get a better description of the problem that makes sense before having any work done.

james.kerr@sasktel.net