When I'm driving my car it runs good at town speed but ,on the hwy it acts funny. When I reach 45 and up and let off the gas my rpm drops out and acts like it's in nuetral. But when I give it gas it won't pull untill it hits 2500 rpm
It sounds like what you are experiencing is transmission related. I would want to check the automatic transmission fluid (ATF) level and condition. It may be low on fluid.
You may smell burnt fluid if the trans has been slipping. If you can feel, and hear, the engines rev up but no forward motion until higher rpm, that is definitely due to a transmission problem.
If you’d like a second opinion, contact a certified mechanic who can diagnose your driving symptoms and service your transmission fluid if necessary.