Volvo Repair: 850 need block heater to start below 0 celcius, premium gasoline, oil rings

Question
1995 volvo 850, non-turbo 20 valve, 220000 km.
Here's my problem: The car has new sparkplugs, wiring, rotor and cap distributer, new rpm sensor, new temperature sensor and new fuel filter. There are NO error codes stored in the ECU...The car start with no problem when it's warm and runs OK and has never stall while driving. It will not start when it is below 0 celcius unless I connect the bloc heater for an hour or 2 depending on how cold it is outside. Also the battery is good and I use mobil one oil. I use to be using 8.3l per 100km and now I'm using around 10.5-11 per 100km...
Any help would be very much appreciated


Answer
Hello,
           You might consider changing to premium gasoline...I only use premium in all my stuff..higher octane better performance in extremes.
        Install a new coldstart valve...it gives a small blast of gas into the manifold when car is cold.
            Have your compression tested.
        test cylinders for worn oil rings.
                 Good luck,
                   Bilbo