You can just start driving with todays fuel injected cars and they warm up faster. The auto transmission is programed to shift early, just like how a manual driver would when the engine is still cold.

 

...The auto transmission is programed to shift early, just like how a manual driver would when the engine is still cold.

Correct me if I am wrong. Atleast today morning after a real cold start (car had not been used for couple of days), I drove right away and when cold I thought it stayed longer in a certain gear before up-shifting.

Also, does a colder engine need more fuel initially than a warmed up engine? I am tempted to think so since the AVG mpg number dropped quicker than I expected in the first quarter mile or so.

 

Wow. My AT has never shifted above 2.5k rpm after a cold start, even at -30C (-22F) cold starts...its fairly easy to do as I don't press the pedal down so far and just let it take me down the road for a 1/2 mile or so.

I can tell you that until you engine fuel map moves from open loop to closed loop and you drive above 3K RPM...it is going to guzzle the fuel...

 

...

I can tell you that until you engine fuel map moves from open loop to closed loop and you drive above 3K RPM...it is going to guzzle the fuel...

??

At what rpm is it shifting above 3k? Cars do run rich on cold start to heat up the cat converter quickly for emissions.

That would mean that if you want to try to squeeze out every last drop of mpg, it is better to let the engine warm up for a few minutes.

 

All depends on how cold it is for the cold start you are referring to. Personally anything above about 30F I let it run just for a min or two to get the oil flowing, anything in the singles I will let it run 5-10 min. But below zero, I will plug in the block heater, let it run for the same 5-10 min, but sometimes longer if clearing snow off the car or scraping glass is needed. Then after starting to drive, always take it as easy as possible til things get warmed up.

 

No need to warm up a modern car. I fire mine up on cold mornings and let it idle for 15-20 minutes so it's warm when I get in though.

 

This has been talked about every winter in many threads. There is no benefit in letting a car idle to warm up, just the opposite in fact. You should start the car & begin driving easy. The car will warm up much faster with a small load on the engine & burn off any condensation better. When idling it doesn't get warm enough to burn off the condensation until you start driving anyway so just start the car & drive easy. All you are doing when letting it idle is wasting gas. If you use the proper 0w-20 synthetic oil it will flow just fine even at very cold temps. Again, the key is to just drive easy until the temp comes up to normal operating range but remember that oil temp takes much longer to reach proper operating temp so wait a while before driving it hard in really cold temps. Also if you live in a really cold area I would always use a warmer for the engine oil or block heater. :thumbsup:

 

...The car will warm up much faster with a small load on the engine & burn off any condensation better. When idling it doesn't get warm enough ...

I do not live in a extreme cold area. I totally agree with above and based on my attempt trying to warm at idle, I am inclined towards not warming it up on a cold start but just driving gently...

At least in my case the current pursuit was to minimize the fuel consumed and for that scenario, idling at cold only dropped the avg mpg reading by a few points but not raising the temperature much whereas driving it away heats it up quite quickly...

 

I don't mind wasting gas. I also don't care if it's good for the car or not. I will be warm.

On hot days I start my car in the morning and leave it running all day long so it will remain cool. When calling on a client, I just lock the doors with the remote!

I also once left a Honda civic running for 5 days while in Colorado because it was freezing cold and I wanted it warm when I got in!

I don't get many green awards.

 

I guess you don't. :lol: To me it's just not a big deal. The car is warm in a matter of 3-5 minutes & cool in the same time. Not worth it to me to just throw money away. I can afford to, but I choose not to. I just have issues with giving more money to oil companies than needed. :ugh3:

 

Rotfl

 

I'm not trying in any way to be confrontational with anyone here but yes you should absolutely let your car warm up. It has nothing to do with the fuel injection either. As oil gets colder it gets thicker and the viscosity properties are greatly diminished. I've read a pretty in depth study on this matter so that is why I'm responding on it. Firing the engine and then putting it in drive 15 to 30 seconds later on a cold engine is not a good thing. It will increase engine wear and it will result in diminished fuel mileage. In point of fact you should let your car warm up some even during the warm weather months because just sitting in the oil pan even at room temperature the oil will lose some of its viscosity. The colder it gets, the longer you need to let your engine idle before putting a load on it. For instance, this morning when I started my Tacoma it was 26 degrees F. I let the truck idle for at least five to six minutes before putting a load on the engine to ensure the oil has completely warmed up and thinned out to its optimal properties for engine protection. I do the same in my Corolla. During the warm months when I start my car for the first time in a day or the first time in several hours I still let it idle for 1 to 2 minutes to get the oil thinned out properly. I agree that modern cars are a lot more efficient about this but oil viscosity still has its physical limitations based on ambient temperature, even synthetic oil. Again I only offer this up because of an in depth study that I read regarding this very issue. Letting your engine warm up on cold mornings is a very good idea.

 

I'm not sure what you've been looking at but it's the opposite of every article & study that I've read over the past many years. Letting it warm up will put more wear on the engine since oil pressure is very low & takes longer to warm the oil at idle. Even common sense works if you think about it. The key is not putting a heavy load on a colder engine, just a nice light throttle. The engine warms quicker which brings everything up to ideal operating temp which will save you gas, not use more. :ugh3: Idling a car does nothing but waste gas since the car is not moving & always uses a lot more gas until warmed up, just as LeanBurn said too. You need to look at the ability of 0w-20 synthetic oil to flow at very cold temps, it's amazing at how cold it can be and still flow great & protects a cold engine from start up. To me using a good 0w-20 synthetic oil is key to engine start up protection at any temp.

 

1) Oil is thinner when cold(as in 0winter-20) so it flows to all parts of the engine faster
2) The mixture is enriched because gas doesn't atomize as well when cold so you need more for a smooth burn.
3) The transmission keeps the rpms high to warm up the transmission fluid. Warming up the oil is a side effect.
4) High idle on start is used to get the catalyst to light-off.
5) The engine is open loop until a certain temperature. It is running really rich(2) which drenches the o2 sensor in fuel making for a poor reading. After that it moves between open and closed loop based on load.

You should start driving about 30 seconds after starting to give the fluids a chance to get through the engine.

 

1) Oil is thinner when cold(as in 0winter-20) so it flows to all parts of the engine faster
2) The mixture is enriched because gas doesn't atomize as well when cold so you need more for a smooth burn.
3) The transmission keeps the rpms high to warm up the transmission fluid. Warming up the oil is a side effect.
4) High idle on start is used to get the catalyst to light-off.
5) The engine is open loop until a certain temperature. It is running really rich(2) which drenches the o2 sensor in fuel making for a poor reading. After that it moves between open and closed loop based on load.

You should start driving about 30 seconds after starting to give the fluids a chance to get through the engine.

sorry, thats wrong information.

a sae0 @30F is much thicker than a sae20 @200F

we use multigrade because a sae20 @30F is way too thick, and a sae0 @200F is way too thin, etc.

a colder thicker oil pumps at higher pressure and protects less than an oil that is hotter and flowing more at lower pressure. i suggest some reading over at BITOG. a car is meant to work best at operating temperatures, which is not dead cold.

 

Much of what has been presented as fact in this thread has been opinion (obviously not all). I still say you will do no harm starting a car and driving off in it under almost all circumstances.

A little common sense goes a long way here though.

If it's -22 F I'm sure you are going to want to warm it up so you don't freeze your ass off and you can see out at least some of the windows.

 

I use a block heater timed to turn on 3 hours before departure out of my garage...and I have a heated seat cover...so my buns are toasty as soon as I get 1/2 block from my house. I idle about 5 seconds at that temperature before pulling out of the driveway.

 

OP so you don't have to wait and warm the car up. You can purchase a Viper 2way pager alarm system. Some models have an auto start feature. Start the car while your in the house or while walking to your car. The system is designed to only run for a minute, so its ready by the time you get there. It has security features while the car is running. You have an automatic, an auto start really will be convenient for you.

 

if yours is running only for a minute then you should smack the person who installed it. default for my viper is like 10 minutes although i've done as much as 30 minutes with the starter.

as for warm up. i usually just start the car, adjust myself in the car, find a good radio station and im off.

i have a remote starter and i don't use it for warming up the engine but for warming up or cooling down the car. it will defrost my windows, warm up the cabin and have everything ready for me to go. its a comfort thing.

 

I have a Prius. I hit the power button and go. The engine eventually comes on and it warms itself up.

I warmed up my older Toyotas for 2-5 min, but it mainly had to do with poor driveability. They were carbureted and didn't like the cold weather. Back then I parked my car outside in the element. Of course, this was in Colorado.

As I replaced them with newer fuel injected Toyotas, I start the engine and wait maybe 10-15 seconds and then gently go. I have a garage now, so the car never gets extremely cold either. Also helps that Western Washington doesn't get as cold as Colorado.

 

I think you answered you're own question. If it was bad for the engine you wouldn't have made it this far.

The main advantage of synthetic is that it breaks down slower. You can get the same performance out of it but you have to change it more frequently.

 

I was being a bit tongue-in-cheek. There is no evidence about whether this will make your engine last longer or not.

 

OK... everybody said their piece here. Let's end it now.