7506 vs 1156: What’s the Difference?

7506 and 1156 refer to two different types of tail light bulbs sold by Osram Sylvania. The main difference between these two bulbs is that the 1156 bulb has a higher wattage rating.

If you’re replacing a burnt-out tail light bulb or switching out your existing bulbs for ones of a different color, it’s important to use replacement bulbs that are compatible with your car’s requirements. In this article, we’ll go over the differences between 7506 and 1156 bulbs, and we’ll share with you some additional information you might need if you’re thinking of swapping out your tail lights.

7506 and 1156 Comparison

So, how do these two bulbs actually compare to each other? As we’ve mentioned, the only real difference is the watts that each bulb requires to work.

The 7506 is a 21-watt bulb, while the 1156 is a 27-watt bulb (technically 26.9 watts, but close enough). The 7506 bulbs also use a nickel base, while the 1156 bulbs use a brass one. Other than that, these two bulbs are functionally the same. 

However, while they are very similar, they can’t necessarily be used in the same way. We’ll go into more details in the next section. 

Are These Bulbs Interchangeable?

In short, almost but not quite. It depends on what kind of bulbs you originally had and what you’re trying to replace them with.

Basically, what you need to know is that you can use a low-wattage bulb in a high-wattage socket, but not the other way around. Therefore, you can use a 7506 bulb in a 1156 socket, but a 1156 bulb can’t go into a 7506 socket.

If you try to put a 1156 bulb in a 7506 socket, you’ll probably run into some issues. In particular, your car might start giving you false “bulb out” warnings, your turn signals might display unusual behavior like blinking a lot faster than normal, and eventually, the connection pin in the socket will get burned out and your tail lights will stop working entirely.

How to Change Your Tail Lights

Changing your tail lights is a pretty simple and straightforward process. Here are the steps necessary to correctly replace your tail light bulbs:

  1. First, put on a pair of nitrile or latex gloves before handling your new light bulbs, in particular if you’re replacing your original bulbs with halogen ones. This is because the salt and oil on your skin can actually damage the bulb, significantly decreasing its life and potentially causing it to shatter in time.
  2. Open your trunk/tailgate, and remove the panel covering the tail light assembly. Some vehicles may require you to physically remove the whole assembly to change the tail lights, which you can do with a screwdriver.
  3. Once you’ve exposed the tail light assembly, you can unscrew the bulb sockets from the assembly. Remove the bulbs from the sockets.
  4. Install the new bulbs into the sockets, and screw the sockets back into the bulb assembly.
  5. Reattach the bulb assembly if you have removed it; otherwise, just replace the panel leading to the assembly.

Tail Light Types Info

There are presently several different kinds of lights that exist for automotive use. Let’s quickly look at each of these types and see what makes them different.


Incandescent bulbs are the most basic lightbulbs out there. They contain one or more filaments, which heat up and produce light when a current runs through them. The bulb is filled with a gas, usually argon, that prevents the filament from burning out prematurely.


LEDs (light-emitting diodes) are much more energy-efficient than incandescent lights and also operate at much cooler temperatures. Instead of a traditional filament, LEDs work by running a current through a diode. 


Halogen bulbs are a type of incandescent bulb, but instead of argon, these bulbs are filled with halogen gas. In an argon bulb, the filament deposits soot on the inside of the bulb over time, causing it to glow more dimly. The halogen prevents this soot buildup from occurring, which helps the bulb stay brighter for longer.

Halogen bulbs also burn a lot hotter than argon bulbs, and thus need to be made from harder glass than argon bulbs in order to resist the heat.


Xenon bulbs are also filled with gas (namely xenon) but work differently compared to incandescent and halogen bulbs. Instead of using a filament, xenon bulbs use a current that passes between two electrodes, which causes the gas inside them to glow.


While the 7506 and 1156 bulbs are pretty similar overall, there are certain key differences between the two that limit how each of them can be used. The main thing to remember is that 7506 bulbs require fewer watts than 1156 bulbs.

If you have a car that takes 1156 bulbs, you can usually substitute them for 7506 bulbs, but not the other way around. In other words, you can only use a bulb that uses the same or less wattage than the socket it’s designed for. This is an important detail to know if you’re thinking about substituting one kind of bulb with another similar kind of bulb.