Those of us who live in a four-season climate are used to the idea of allowing our vehicles to warm up on a cold winter's day. But with the technology in today's automobiles, is this still something we should be doing? The simple answer is no. For the most part, letting your vehicle idle for long periods of time in the cold is not only bad for the environment, but can cause serious damage to your engine and emission system.
In the past, most vehicles employed a carburetor to deliver fuel to the engine. Today, almost all cars, trucks and SUVs on the road use some form of electronic fuel injection. In a cold engine, the computer management system tells the fuel injectors to stay open longer allowing more fuel to flow into the engine in part to keep the engine running cool. Trying to warm up the engine at slightly above idle speed is actually doing the reverse and inviting additional problems.
Cold engines produce a much higher level of unburned hydrocarbons as fuel needs heat to burn efficiently. Even the best catalytic converter is unable to process 100 per cent while running at maximum temperature, so allowing the engine to idle for extended periods of time can start to clog the system.
In addition, spark plugs may also become plugged or dirty due to inefficient fuel burning. Older vehicles required regular maintenance, calling for spark plugs to be changed every 30,000 km. Today, almost all engines employ an electronic ignition system that requires spark plugs to be changed at intervals in the range of 100,000 km. An engine at idle for extensive periods of time could dramatically shorten the life of your plugs, causing you to spend hard-earned money on unnecessary service and maintenance.
A better approach is to start your vehicle and let it run for up to one minute before driving away. This will allow fluids to begin flowing through the engine and then warm up to efficient temperatures under normal driving conditions.
Should the temperature outside dip below freezing, allow a maximum of four to five minutes of idle time before driving away. This should be just enough time to clean off any snow or ice that may have accumulated on the windows. While you may not be warm as toast on the way into work or school, you will benefit by saving money at the pump and garage and by driving a vehicle that runs cleaner and more efficient for many years to come.
yes I warm up my car every morning or when my car is sitting for a long time (ie dinner or movie)
usually wait until the temp light is out!!
b/c my 2 cars have temp light when cold is BLUE I usually wait until that goes out b4 I drive away!!!
allowing ur car to idle until its warm isn't always the best since ertain parts will never heat up by just idling.
the best compromise is to start ur car, give it a second for the idle to stabilize, then drive gently until its warm.
US EPA said "little warmup" rather than "no warmup", and the best way to warm up is to drive it!
COLD TEMPERATURES: Emission control systems take longer to warm up and
become fully operational in cold weather. However, idling will not help. Modern
vehicles need little warmup; they’re most efficient when being driven. Idling for long
periods in cold weather can actually cause excessive engine wear.
I have a ScanGauge, and when it is dead cold, the readings overall are higher than usual. I usually wait until the readings are at normal before I drive.. usually 2-5 min idling..
The engine runs at higher RPM during idle in cold days anyways until the temp reaches normal.
Warm up the car is for the lube to reach the shaft and some other important part of the engine. Not mainly for the fuel.
Warm the car is needed when it's cold, simple. But not like 10 minutes crap, that's just plain stupid and common sense.
If a statement like "The new cars now do not need warm up." is just wrong.
Warm until idle drop like 1 or 2 minutes or until the idle drops.
There are expensive cars that comes with auto warm up even when you turn off your car, then those are ok. (not talking about the remote start thing)
發表於 2010-12-29 09:48
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