AC White Paper: Air-Cooled Porsche 118/115 TTG Driving Lights


Hella 118/115 Through-the-Grille Driving (and Fog) Lights

Through-the-Grille 118 driving lights were first offered as a factory option for MY1968 (SWB) and continued through the LWB era (1969-973). They cleverly mounted through special horn grilles with openings cut out. And Porsche provided threaded holes on the interior for the mounting of the brackets.

Hella 118/115 Driving/Fog Lights

There are three original version of what are commonly called Hella 118 driving lights that are used for the through-the-grille (TTG) application (and fog lights) on the LWB Porsche 911’s. Two of them were versions of the RoW (Euro) model, one for Italy and one for everywhere else. And the third was for the U.S. Both RoW versions used halogen bulbs but they were not permitted in the U.S. due to DOT regulations and a tungsten bulb was used there. Today the Euro versions are typically referred to as “118’s” and the U.S. versions as “115’s”.

Note: Much of this information was gleaned from past posts in the Early 911S Registry. Many thanks to: 70SATMan, D. Miller, Soterick, 66S, Allen Henderson, VintageExcellen, kenikh (ah, the good old days)


Euro 118 Driving/Fog Lights

Hella 118's (lenses are 118mm in diameter) and use halogen bulbs, H3’s in most places and H1’s in Italy. They are commonly used in the TTG application as driving lights where they use clear lenses with vertical lines, and are also be used as fog lights where they use fluted lenses. Driving lights are always clear while fog lights can be clear or amber

OEM Porsche factory 118’s had an extra rivet on the back of the lights, so-called "5 rivet" lights, with the fifth rivet providing a way to secure the H3 bulb hot lead. 118's have a thinner bezel so that about 118mm of the lens is exposed.

Euro 118 Details

  • TN5 reflectors
  • Hella 4571 118mm lenses
  • 118mm reflectors
  • Halogen H3 bulbs
  • 5 rivets (extra rivet secured the H3 bulb hot wire)
  • After market assemblies are 4 rivet with no internal ground spade
  • Large grommets
  • Extra internal ground spade
  • Driving lights use clear lenses with vertical lines and are always always white (the exception is France with amber)
  • Fog lights use clear or fluted lenses and can be white or amber (the color is added by a coating on the the reflector)
Original 5-rivet Euro 118 Driving Lights (note the H1's)


Original 5-rivet Euro 118 Driving Lights

These are for 914's (note the different mount) but it's a great illustration of how the fifth rivet was used for the H3 bulb hot wire.

Again, these are for a 914 (black vs. chrome housings) but show the 5-rivet configuration.


 Rare and unusual amber driving lights for France


Original 118 Euro (H3 bulb) Fog Light Configuration

 Euro Italian 118

  • H1 bulbs that mount from the side (the H1 bulb is too long to mount in the middle)
  • Hella 4571 118mm lenses
  • 118mm reflectors
  • 4 rivets as one is not needed to secure the H3 hot lead
  • Enlarged grommet hole for a 2 wire harness
  • 2 internal ground spades
  • Aftermarket version
    • one ground wire inside and a
    • grommet sized for the one hot lead

Italy 118: H1 bulb mounted on the side instead of in the center

Four rivets vs. five for RoW due to H1 bulb instead of H3 bulb. Large grommets for two wires.



 U.S. 115 Driving/Fog Light Details

Hella 115's are fitted with tungsten bulb fog lights for the U.S. market. The exposed lens diameter is 115mm vs. 118mm diameter for the 118's. Housings for 115's and 118's virtually the same. The 115's have a slightly wider bezel than the 118's, making the exposed lens 115mm as mentioned.

These can be used as TTG driving lights or fog lights. When used as driving lights the lenses are clear with vertical lines. As fog lights the lenses can be clear or amber (yellow) which is determined by the color of the reflector (not the lens).

  • Housings same size as 118’s
  • Driving lights use 118 reflectors
  • Fogs use TN4 reflectors
  • Exposed lens has 115mm diameter and these are often referred to as “115’s”.
  • Larger bezel than the 118’s
  • TN4 lenses (TN1-TN2 lenses are 115mm and interchange with TN4 lenses)
  • Tungsten 45w bulbs
  • 911's use chrome bodies, 914's use black bodies
  • Driving lights use clear lenses with vertical lines and are always white
  • Fog lights (usually referred to as "TN4's") use clear or fluted lenses and can be white or amber (the color is added by the reflector, not the lens)
Driving light on a 1970 911T

 Items common to 118’s and 115’s

  • Chrome housings (basically the same)
  • Bezel holding bracket/screw
  • Swivels


In the pecking order of Hella 118’s, 5-rivet originals are very hard to find but all are comparatively rare. There have been many reproductions made over the years continuing to today.The ranking goes something like this:

  • 5-rivet 118’s (very valuable)
  • 4-rivet 118’s (Italy)
  • 115’s (always 4-rivet)
  • Reproductions

For those interested in originality there are a couple of things to watch for. There are many reproductions, many very well done, and at times they are presented as NOS. Also, it’s common to see bastardized assemblies used disparate parts.

Mounting Brackets

SWB and LWB cars used different mounting brackets. The best way to describe it is with pictures, SWB on the left, LWB on the right:


Option Codes

  • 1968 MY US cars, but only H-3 versions were available:
    - 9420 -- driving light (not available on 912) – Oddly equipped with H3 bulbs
    - 9421 -- fog light with yellow reflector

There is no accompanying tungsten bulb light unit (i.e. U.S.) in the 1965-1968 parts catalog

  • Euro (RoW) - M 431 : Additional long range driving lights, yellow, above bumper
    - U.S. - M 432 : Quartz-iodine long range lamps, white. Above bumper. (Through-the-grille driving lights)
    - Euro - M 433 : Halogen fog lights, white, above bumper
    - Euro - M 434 : Halogen fog lights, yellow, above bumper

Part Numbers

911.631.121.01 Driving light, H3, white, Euro
911.632.202.00 Fog light, H3, white, Euro

911.631.121.10 Driving light, H3, yellow lens, France
911.631.202.10 Fog light, H3, yellow lens, France

911.631.211.00 Driving light,amber, Italy (H-1)
911.632.213.00 Fog light white Italy (H-1)

Glass lens:

901.631.211.00 Driving lights

901.631.202.00 Fog lights, clear

901.631.202.10 Fog lights, amber