Double consumption at maximum speed

Servus people, I drive a 96-er Honda Civic Mb1 with 83KW and have the following problem. If I’m on the highway with my Civic and want to go at top speed then it takes forever until it has reached 180 km/h. At the 192km/h registered. And then it stops at 180 or goes back to 170 km/h. But that’s not the only thing that increases consumption. Yesterday for example I drove about 80 km full throttle and have a verbuch of about 14-15 Lit But they can’t help me either and thought that the valves might have to be adjusted. The engine only has 120 Tkm down. I really don’t know any more. Please help me if you know anything…