Make Light of Winter

Bulb test
28 Nov, 2007 12:04pm

Which headlight bulb provides the best visibility and safety? We assess 30 lamps in the UK’s biggest test...

Give yourself a better chance of staying safe this winter by upgrading your car’s headlights. Around £30 will buy you a pair of state-of-the-art bulbs which can dramatically improve your night vision, as well as reduce the risk of a collision. All the latest electronic in-car safety features – such as anti-lock braking, traction control and stability programmes – will count for little if you can’t see where you are going.

It’s important to fit the right bulb because, as our test shows again this year, buying anything but the top names is a lottery. Some cheap units produced worrying degrees of glare for oncoming drivers, as well as very low levels of light on the road and major differences between lamps. Getting the headlights aligned as you fit new bulbs is essential.

For this year’s test, we concentrated on the single-filament H7 – the most popular halogen bulb in Europe. Performance versions have been around for some time, offering 30, 50 and 60 per cent more light 75 metres in front of the car. But the past 12 months have seen the arrival of 80 and 90 per cent versions. Do they work? We test the leading standard, plus 30, plus 50 and higher (we list them as 50 plus) and blue bulbs, as well as one designed for off-road use, to deliver our verdict.

The test
Philips’ 75-metre light tunnel at its plant in Aachen, Germany, allowed us to measure beams accurately, and see the patterns displayed on a simulated road. We assessed pairs of each bulb, and adjusted our Volvo V70 test car’s headlamp each time until there was no glare for oncoming drivers.

Our beam rating is a combination of the light at 50 and 75 metres in front of the car, and an average of readings from two bulbs. Build geometry and light output were also measured against EC regulations. Prices are for a pair of bulbs, and were taken into account only where there were big differences, as costs can vary wildly. We have listed our sources as a guide.

Light show: best vs worst

Seeing clearly

On the road, the difference between the best and the worst bulbs was enormous. Adjusted to prevent glare, the Classic Professional barely reached 40 metres, with a mass of distracting light just in front of the car.

Peripheral vision was a little over six metres either side of the driver.
Our Best Buy, the Philips X-treme Power, illuminated the road over 90 metres away with a 20-metre-wide beam and a bigger spread of usable light ahead of the test Volvo. That’s easily the difference between having a collision and avoiding one.

Feeling blue?
While one section of our test is devoted to ‘blue’ bulbs, the best deliver white beams and headlights. These products were created around seven years ago to imitate the then new gas-discharge xenon or HID systems which were appearing on top-of-the-range models from BMW and Mercedes, giving off super-bright beams and adding a blue tinge to the headlights.

Most halogen imitations use the latest technology to boost light output. And they need it, as the colour change from yellow is achieved by coatings or filters which rob light from the beam. In poor-quality units, the result is low levels of light and a kaleidoscope of colours around the edges. In this test, ‘blue’ bulbs performed mid-way between the plus 50 and plus 30 untreated samples.


Head and shoulders above the rest in this test was the Philips X-treme Power, which put in a performance no rival bulb could come near.

However, if you want to spend less than £30, go for the Philips Premium. And for those who prefer the white look, the best is from Narva. Just bear in mind the trendy blue coating has an adverse effect on bulb performance.

The standard entries from Bosch and Halfords get our vote. But most of the build and beam issues were in this class, and it’s well worth upgrading to a plus 30 or 50 plus unit to ensure decent quality.

1 Bosch Premium
2 Halfords Value Twin Pack

Plus 30
1 Philips Premium
2 Bosch Xenon Power

50 plus
1 Philips X-treme Power
2 Philips Vision Plus

1 Narva Range Power Blue
2 Philips BlueVision