Can you still maintain your SE rankings even if you don't update your site?

Generally speaking, the more updated and content rich websites have a higher chance or maintaining or improving their PR. However in small circumstances , quality backlink rules....

 

I think it depends on what you start with. I know some sites that have changed very few things and are still rocking as far as PR goes, while others are constantly changing things and making the PR lower and lower each time.

 

in terms of SEO, backlinks is king. Content update is only needed to make Google crawl your site more often.

 

It has been proven beyond doubt that search engines like fresh content. Though you could sustain your ranking without adding fresh content for sometime, it would not be possible for eternity. On the contrary, just adding fresh content won't give you high rankings as the effort would have to be backed by on-page and off-page initiatives.

 

I think updating your content is very important because google crawled your new content every now and then. It will help your PR to get higher.

 

Competition is too high if you are not updating your website then Google is not going to cache new content. Content is the king.

 

I think you should update your content where it makes sense to, but don't expect an SEO boost just because of it.

 

Backlink is not equivalent to content and good & unique content is surely the king but for that king to be seated in his chair, he has to climb the ladder called backlinks; in other words, backlinks help the contents to climb up in serp but they themselves are not powerful enough to make the site top, imo