I had SS bulbs in my leased 2001 Sport Trac for a year before I gave it back to Ford and bought my 2003 Sport Trac late in the model year I removed te bulbs and put the OEM's back in, and put the old SS bulbs into my new 2003 Sport Trac. I traded it in last January after 4.5 years and never had a bulb burn out. So my SS bulbs had over 5 years on them.
Maybe I just got lucky and got the pic of the litter when I bought my SSs? I also recall that my wife drove the truck much more than I did and we did not drive it a lot at night so that might account for the SS bulbs lasting so long.
I'm sure we all have read the instructions that say not to touch the glass part of the halogen bulb and if you do to wipe it off with a clean cloth. I was told that it is possible that the bulbs may have been been contaminiated before leaving the factory and it is always best to clean them even if you never touched them.
I know a lot of people have complained about the short life of the SS bulbs, and I just wonder if that might be due to touching the bulbs and then just wiping them off with a cloth or paper towel, which is not really removing all of the contaminates.
A trick I learned in Europe many years ago where they have used haogen headlight bulbs for about 40 years. I insert the bulb into the socket with gloved hands, then clean the bulb with an alcohol wipe and dry with a clean paper towel. I use a fresh alcohol wipe and paper towel for each bulb so I am not contaminating the second bulb with any dirt cleaned off the first bulb. It may sound a bit anal, but it did work for me
...Rich