Is it necessary to warm up your car in the morning?

Answer 1

It is necessary on cold, especial extremely cold days. REASON BEING: Is that it takes the oil to reach it's proper viscosity longer time than on warm days. When you do start car, don't race it or you'll be doing more damage. Let it stay at idle for about 3 - 5 minuets until you see the temperature gauge start to get to move to a hotter position, or better yet, until you have heat. Reason is that thick oil cannot easily flow though tiny holes in crankshaft, push rods not getting oil into small spacers in cylinder block, valve guides, rocker arms and oil control rings leaving a dry cylinder wall, which causing wear to cylinder bore. Sometimes in really cold places, they suggest using a lighter gauge oil.

I will give my answer which is in opposition the the above answer somewhat. In years past when cars had carburetors it was a necessity to warm the engine up before driving off because the engine simply would not run correctly until the carb got warm. Today it is a bad idea to let the car idle for more than a couple of minutes max before driving off. Reason being is that on todays modern engines with computer controlled fuel management systems it is not necessary and is in fact a waste of fuel and pollutes the atmosphere plus harms the converter. Modern fuel injection systems do not need to warm up to work properly as an old carburetor did. They work instantly and the ECU adjusts the fuel/air mixture to compensate. Modern oils of today are also a far cry from what they were decades ago. Modern Oil sticks to all parts better today than in the past. This is not the same formulation that we had decades ago. There is a thin layer of oil on all parts when you start the engine due to modern refinery processes, so you are not causing wear to that engine if you drive slowly until it reaches full operating temperatures. Modern vehicles will warm up very quickly if driven but not so fast if sitting at idle. You are also doing your catalytic converter no good by letting this very rich mixture of fuel/air enter a cold converter that does not work well when cold. Just drive away slowly, avoiding full throttle until the engine is warmed up. This is 2010 not 1955. Things have changed.I can see the above point of view. But there is still a disagreement on oil. yes there will be a very, very thin layer of oil on the cylinder walls, but even sythetic oil will settle downwards ,and on a 20 degree day will be sticky and wipe off in one piston stroke. it still ,in my opinion, takes a little bit of time for oil to thin out as it gets warm. Has enyone ever went to change oil on a 10 to 20 degree day. It barley comes out of the drain hole, unless you let it run for even a minute, can you picture this oil flowing through tiny openings. however, point is well made that idleing and driven slow for the same amount of time will do the same exact thing. Main point is ; don't reve the engine right away, or drive fast for a few miniutes. Note: in places like Alaska, they use a heating source overnight because the car may not even turn over or do it slowly, because the oil is so thick.

Ans 3 -The second answer is the correct one. Letting a modern engine idle for long periods is not good with modern oils being as 'clingy' as they are.