why does your car create more emmisions and wear on the moving parts when its cold?

Answer 1

Emissions are higher because the catalytic converter that gets rid of emissions only works when it is hot and you cold engine has not yet made it hot.

Wear is worse because the lubricating film of oil that separates moving parts is not yet in place while the engine is starting.

Answer 2

Because it is cold and petrol vapour condenses on cold surfaces and liquid petrol washes oil off cylinder walls causing wear and dilutes engine oil causing wear wherever the oil goes.
To compenste for the fuel which condenses the engine must be fed excess petrol when cold, which causes extra emissions.
The petrol in the oil boils out with and condensed water when the engine is hot, but if your engine does not get hot you need 3 or 6 month oil changes to avoid excess wear. Cold running will also rot your exhaust real quick.
This is avoidable by not doing cold starts, leaving the engine ticking over all night is wasteful, but Kenlowe do a mains powred heater, Hot Start or something which with a timer means yur engine need never start from cold from home, unless you have a power cut, and it demists from the moment you start up, I cant use one as I park in the street but I would use 1 if I had a Car Port ofr Garage.

Answer 3

The wear is caused by the lubricating oil taking some time to reach every part of the engine, and also taking some time to reach the temperature at which it performs best.

The increased emissions are caused by a number of factors:
The catalytic converter in the exhaust system of modern cars, that converts un-burnt hydrocarbons, carbon monoxide and oxides of nitrogen to water, carbon-dioxide and nitrogen only works at high temperatures, and takes some time to warm up.
The fuel doesn't atomise properly in a cold engine, so doesn't burn as efficiently.
The fuel can condense onto the cold surfaces within the engine, again meaning it doesn't burn as efficiently.
In a diesel engine, the air near the edges of the combustion chamber may remain cold due to the proximity of the cold engine components, preventing fuel from burning in those areas.

The atomising issue is more of a concern in diesel engines than petrol engines (but is still a slight concern in petrol engines).

The condensing issue is not as much of a problem in direct-injection engines (petrol or diesel).

Answer 4

well dear, when the engine is cold - the oil is 'thicker' (less viscous) and does not run freely into all the small channels inside the engine. Also, there is residual water vapour in the combustion chambers and exhaust system - this is obvious as white smoke from the exhaust pipe. Once the engine reaches it's optimum operation temperature the oil runs more freely and the exhaust fumes are clear.

Answer 5

Poor lubrication (oil is more viscous at low temp, thus does not go in all crannies and moves slowly) is the wear, Low temp is the issue with emmissions, as the air fule ratio need to be "rich" when an engine is cold to prevent stalling and the catalyst operates only at high temperature.

Answer 6

engine dameage is caused on a cold engine due to the oil not at operating heat also the oil has had time to drain to the bottom of the engine. as for emmisions....pass....as long as you have white smoke not blue everything is ok.

Answer 7

Engine wear happens when the car is started. Use a good oil 5w-30. to help with lubrication. It is a thinner oil and works better in cold temps.

Answer 8

as I understand (and not totally for sure, brother is a mechanic) there is an optimal temperature for the engine to operate and the engine and its radiatior is in constant battle to maintain the combustion temperature.

Answer 9

It works harder to get started and stay started.