I own a Saab 95. I runs but at high way speeds it will not stay at a steady pace. When you accelerate it hestates or stalls then there is a rush of speed. If you try to keep a constant speed it will start to hesitate unless you accelerate. This started to happen when I changed the radiator but really cant see the connection. Since the problem has started. I have checked the oil just in case a bad head gasket but oil looked good. Has a new fuel filter. Air filter is pretty new. Changed out the crank shaftspeed sensor. It has a turbo but have not noticed any air leaks to this system. I really like the car and would like to keep it. It doesnt burn oil so think there is still like in it even though it has a lot of miles. Would like some advice as too what else it might be.