Does having a sitemap submitted through Google Webmaster Tools increase your ranking within Google? In short, through the testing that we’ve done, we haven’t found this to be the case. There doesn’t appear to be any correlation between better rankings and sitemap submission.
So if you ever hear someone mention that using XML sitemaps boosts rankings, pay no attention to them because they don’t know what they’re talking about 🙂
What submitting an XML sitemap is good for is getting your site indexed. It makes it easier for Google to know exactly what pages you have on your site and what you’d like indexed.