Which bulb for a replacement H4 headlamp?

Useful information from ABD.

[Links to other items on headlamp upgrades]


H4 Osram Night Breaker Laser 150% Next Generation bulbs 12v 60/55W (pair)

H4 Philips WhiteVision Ultra 12V 60/55W bulbs (pair)
Many MGBGTV8 car owners who have a installed replacement H4 Halogen headlamps as an upgrade to improve the visibility ahead at night from the relatively poor lighting provided by the original sealed beam units will need to choose suitable bulbs. But which bulb will be the question for many? Chris Hunt Cooke has found a useful website - ABD - Automotive Brilliance, Delivered - with information that helps clarify the headlight bulb options.

ABD say the first step is to identify which technology your current headlights use - Halogen, HID Xenon or LED. This is your starting point. From there, you can consider the upgrade options for each technology. With the H4 Halogen headlamp units used for the upgrade from sealed beams the choice is between the various brands offering standard and brighter Halogen bulbs.

Bulb choices for an MGBGTV8 owner
With Halogen bulbs as a standard for replacement H4 headlamp units you have the option to upgrade to brighter Halogens, convert to LED or convert to HID Xenon. ABD have released an updated guide covering what bulbs you need, how to choose the right bulbs, highlighting the difference between Halogen, LED and Xenon bulbs and then describing what purpose each bulb has.
See the ABD Bulb Guide 2020

Brightest Halogen bulbs
While newer technologies are slowly filtering through, the majority of vehicles on the road still use Halogen bulbs for their headlights. If you have Halogen headlights the first thing you will need to know is what bulb part number you need - an H4 bulb for an MGBGTV8 with a replacement H4 headlamop unit. Currently, there are some top contenders for levels of brightness - OSRAM, Philips, RING and Twenty20 and all claim their Halogen bulbs produce up to 150% more brightness than a standard bulb. The ADB guide to the Brightest Halogen Bulbs has a comparison of the quality, longevity and value for money of those leading brands. With a classic car like an MGBGTV8 typically covering between 2,500 and 5,000 miles a year the longevity factor will be less of a concern than for an owner selecting bulbs for a "daily driven car" covering say 10,000 miles or more a year.
See the ABD Guide to Brighter Halogen Bulbs

Road legal upgrades
With up to 150% more light, the upgrades ABD reviews are by far the brightest filament bulbs that you can get right now. They are completely road legal, E marked and come with a warranty. As you are replacing Halogen with Halogen, these are the easiest to fit. The downside to having upgraded Halogen bulbs is their lifespan. Unfortunately the brighter you go, the shorter the bulbs actually last. This is due to the filament inside the bulb burning out at a faster rate.

Replacement LED bulbs are often mentioned - they last longer and are brighter, but whilst the technology adapts and improves the UK vehicle lighting regulations do not. Some regulations date back to the late 1970s meaning newer technological advances will not conform to their vehicle lighting standards or MOT test requirements.

HID Conversions kits work in the same way as OE HID headlights, but are simply designed to fit into a Halogen headlight unit. These kits contain ballast units and bulbs that plug together for a simple installation process. ABD say "the ballast units coupled with the right bulbs can bring some immense light to your vehicle with brightness up by 400%. HID conversion kits are by far the brightest options available on the market. Whilst other options may claim to be brighter these are however often unsafe for you and other road users".


ABD concludes its website article saying:

Upgraded Halogen Bulbs
- These lights are perfect for anyone worried about price or road legalities.They are a simple, no-hassle upgrade choice and provide you with a high increase in brightness.Like every other option, they still have their drawbacks.Unfortunately these bulbs just don’t last as long as LED or HID.

HID Kits
- Aside from the fact that HID kits will cause you to fail an MOT, they are the brightest bulbs on the market.If fitted correctly, they shouldn’t cause any issues.

LED Bulbs - These
bulbs have similar issues as HID kits except there is no reason for them to fail an MOT. There is nothing in the MOT guidelines that would cause a failure but they are still not road legal because they can’t be E marked. With between 150% to 300% more light than standard Halogen bulbs, and the longest life of all the technologies, these can be are a serious upgrade some owners might feel they need to consider.

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