Q: Car stopped accelerating and started smoking while driving on the highway

Hi There, It depends on the color of the smoke you are referring to as the color of the smoke will mean a few different things. White smoke indicates that you may have an internal engine problem, such as a head gasket leaking coolant into a cylinder. Black smoke coming from the exhaust is usually an indication of a rich fuel condition. When this happens, this can be the result of many things such as faulty fuel injectors, a failing mass air flow sensor or a faulty fuel pressure regulator allowing too much fuel to be supplied to the combustion chamber to be burnt. When this happens the result is an excess amount of unburnt fuel being passed through the exhaust coming out in the form of black smoke. Blue smoke coming from your exhaust generally means that the motor is burning the engine oil. This can happen for a couple of different reasons such as worn piston rings or leaking valve guide seals. When this happens, the engine oil is burned in the combustion chamber along with the fuel which is what generates the blue smoke coming from the exhaust. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.