Narrowed Down Problem - Need help with Interface Constructor

A class which implements an interface must implement its members as public (not protected) members and the names of the implemented members must be exactly the same as in the interface:

You should create a base class and not interface on this case.
Hope this helps.

    public enum EngineTypes
    {
        InternalCombustionEngines = 0,
        DieselEngines,
        HybridVehicleEngines,
        EletricEngine
    }


    public enum FuelTypes
    {
        Gasoline = 0,
        Ethanol,
        Methanol,
        Eletric
    }


    public enum VehicleType
    {
        SmallCar = 0,
        MidSize,
        SUV,
        PickupTruck,
        Truck,
        Motocycle
    }


    public class Vehicle
     {
        public int MaxSpeed { get; set; }
        public double ReliabilityFactor { get; set; }
        public string Manufacturer { get; set; }
        public VehicleType CarType { get; set; }
        public int FuelEfficiency { get; private set; }
        public FuelTypes Fuel {get;set;}
        public EngineTypes Engine { get; set; }


        public void CalculateFuelEfficiency()
        {
            if (Fuel == FuelTypes.Gasoline)
            {
                switch (Engine)
                {
                    case EngineTypes.InternalCombustionEngines:
                        if (CarType == VehicleType.SmallCar)
                        {
                            FuelEfficiency = 34;
                        }
                        break;
                    case EngineTypes.DieselEngines:
                        break;
                    case EngineTypes.HybridVehicleEngines:
                        break;
                    case EngineTypes.EletricEngine:
                        break;
                    default:
                        break;
                }
            }
        }        
    }


    public class SmallCar : Vehicle
    {


        public const double LifeSpan = 5;


        public SmallCar()
        {
            Fuel = FuelTypes.Gasoline;
            Engine = EngineTypes.InternalCombustionEngines;
            MaxSpeed = -1;
            ReliabilityFactor = -1;
            Manufacturer = string.Empty;
            CarType = VehicleType.SmallCar;
        }
    }    


class Program
    {
        static void Main(string[] args)
        {
                       var civic = new SmallCar        }
    }