My 1997 328is auto has 47K miles. When I am driving down the highway going 65 mph and I press down my gas pedel the tach quickly runs up to about 3000 then with in a second drops to around 2700 and seems to grab for torc. It is not a down shit way to smoth. It is not slipping when it shifts threw the gears, but what would cause this drop? I think it might be normal, but why would the tach not just keep climbing? Chico