On or around Wed, 22 Oct 2003 08:33:17 +0000 (UTC), "Olly R" enlightened us thusly:
only if it's down about -37°C. At all normal UK temperatures the gas will vapourise. What can happen is that moisture in th air can freeze in the vapouriser causing it to jam, hence the heating using engine coolant - the process of evaporation of gas creates a lot of cold. It's also essential rather than just a good idea to run at least 25% antifreeze all year, as it's possible on cold mornings for the internal water passages in the vapouriser to freeze up before the coolant gets warm enough to prevent this, otherwise.
they all should do this. It's simply not true that you *have* to start on petrol - anyone that says you do or that the vehicle "won't" start from cold on gas is either misinformed or the system is out of kilter. In fact, I've tended to find that they start easier in the cold on gas - the gas doesn't condense out of the mixture in the manifold like petrol does
Mine runs gas-only and starts in pretty much any weather. However, on a dual-fuel system it's a very good idea to start it at least once a day (if used daily) on petrol to make sure the petrol system gets some exercise. When i was running the Sierra, which is dual fuel, I used to be in the habit of starting on petrol first thing every morning, and thereafter starting on gas.