Can I sue a car dealer for giving me false information on a car that I bought from them?

It's hard to answer your question without more detail, but if the car dealer made a false representation of fact on which you reasonably relied to your detriment, you could sue it for fraud.  However, there are a lot of other rules which may be relevant.  For example, if the dealer orally told you that the car had 20,000 miles on it, but the  paperwork accurately reflected that it had 40,000 miles, you are probably out of luck.