Its probably a .279, and not a 2.79. And to answer your question, a high number like that and an additional charge or resisting will enhance your sentence and get you more time, most likely.
High blows carry enhanced statutory penalties, like higher fines, mandatory jail time, etc. The resisting charge may not be much to worry about at this point, it may even be dropped in a negotiated resolution.
You need to hire a criminal defense attorney that has experience challenging the Intoxilyzer. The logs for these machines can be found online and through discovery and will show their readings before and after you blew, maintenance, certification, and when the control gas was last changed. Additionally, there are other challenges relating to the machine itself, how it works, the effects of breath alcohol, radio interference, and other features.
Other than line of possible defense work, there are the standard approaches that need to be evaluated - why were you stopped? Was there a video? Was the officer a certified DRE?
You face enhanced penalties and resisting charge and need a solid defense for sure. Do some research get yourself represented by someone with some solid experience in this area. It may not come cheap, but nether will the alternative. Good luck.
You could very well be right. If you are talking about the preliminary breath test, and it is not clear that you are based on the phrasing of your question, many pbts are flawed when it comes to detecting "mouth alcohol." I use that phrase th refer to any interfering substance in your mouth including alcohol. An interferent will cause an artificially high result. The manufacturers of most pbts explain this to their police agencies right in the manufacturer's manual. Contact a DUI specialist right away.