How to find the Hash tag with more reach?

[Autoschieber]

Hi,

every week I want to post one of the Audi cars on twitter  http://www.kfz.net/autobilder/audi/

so this week my tweet would be:

Alfa Romeo 156 Fotos http://bitly.com/alfaromeo156 #carpics

**Question: **I used the hashtag "#carpics" to get some reach. Is there a tool on the internet where I can see how often hashtags are used? eg. should I choose #carpics or #autopics  ?

[OlegKorneitchouk]

http://hashtags.org/ - Give trends for the more popular hashtags. In your case, I just popped both into search (can do it on Twitter too) and just see which has been getting more results (in this case, I'd go with #carpics)

If someone knows of a better service (maybe checks synonyms, related terms, etc) to choose the best hashtags possible, I'd also be interested.