Be careful switching 168 with 194. Yes, they look identical, but the 168 is aboit 30% brighter and meant to be used in something like a turn signal, where it cycles. The 168 can melt fixtures if you use it in something that's constantly lit.
Like Advintage said , its brighter, and that extra heat can be a problem. I ended up switching money for Led's because it's easy to match that white color, and there's no heat issue.
If you change them, make sure the bulb is in the socket, PERFECTLY. if it falls off, I side the bikes light, it's not a lot of fun to fish back out. It's do-able, with a small magnetic tool, but still a nightmare.
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