Do you keep foot on gas pedal when starting cold car?

It may be different between cars but I generally find after starting the engine, give it a slow rev. before letting it idle. revving a cold car will use a fair bit of fuel. It's not so much about keeping foot on the gas when you start, just don't push the car in it's first few minutes as it's heating up (as you are driving), just drive efficiently.

this is just the case with my 1991 940 GL. hope it helped.

Al Sez;

You should not need to "give it some gass" with a fuel injected engine.

On the other hand I have lived for 30 years where it never gets below freezing. Practical experience in say Alaska may prove me wrong.