Factory Fog Light Bulb?

What bulb is in the factory fog light (01 Yukon XL)? It's not listed in the owners manual. Has anyone upgraded/replaced with a brighter wattage bulb because the factory bulbs don't put out much light! Thanks in advance.

It is an 880. Don't waste your time and money on something like Silverstars in those lights. They are recessed too far into the valance so the design does not put out light to the sides. A design like the Denali should take advantage of the Silverstars but it was a waste on my Yukon. I don't know the wattage of the 880's but it can't be much. I was VERY disappointed. :shakehead

Hi mitchss,
the fog lights in my 01 YXL were dim too.
They had gotten water in them and that damaged the reflectors.
I replaced them with new OEM ones at about $45 apiece, they came with the bulb.
They put out plenty of light now.
I would not increase the wattage, as the lamp housings are made of plastic and the higher temperature may cause problems.

You can really improve your lighting by replacing your headlamps with the projector style ones from the Denali's. I think that mine were $260 for the pair, aftermarket. You will have to cut a groove in the low beam connector to fit the high beam bulbs used there.
The difference is quite great.
Take care, Eggert Johnson :bananasmi