Do you need to warm up your car?

[oiprocs]

My brother says you gotta warm it up, fuel injection or not.

I think he's wrong. Somebody prove me right please.

 

[Demo24]

These days its not so much how the fuel is delivered, more that the oil is not going to be fully lubricating the engine upon start-up. So yes, it's a decent idea to at least drive carefully for a few mins once you have started it up. In colder weather just don't rev as high until things warm up.

 

[CalvinHobbes]

I try and wait 30 seconds to 1 minute after starting the car before going anywhere (longer in cold weather). After that I usually drive pretty easy until the temp gauge gets up a bit. Not sure if this is needed but that's how I do it.

 

[jlee]

My MR2, no boost until it's fully warmed up. I'll drive it (very gently) when it's cold.

My Tundra's manual says not to let the engine idle to warm up. I try to avoid running any engine hard before it has warmed up completely.

 

[franksta]

Originally posted by: DEMO24
These days its not so much how the fuel is delivered, more that the oil is not going to be fully lubricating the engine upon start-up.

Incorrect. Once you've got oil pressure and flow the oil is doing it's job.

A cold motor that is run hard will experience increased wear on the cylinder walls due to them not expanding while the piston does. The coolant is working against you in this situation.
When you reach the proper operating temperature then everything should be good to go. I usually take it easy for about 5 miles around town before any hard acceleration.

 

[desy]

In extreme cold under say 0F definately warm up a min or two, the engine might be OK but all the other fluid systems need to pump a bit.
Mildly cold is debatable
Above freezing temperatures I don't feel its necessary, most auto sources say its unecessary as well

 

[InflatableBuddha]

No. As long as you don't beat on the car while the engine is still cold, with a fuel-injected vehicle, you can start it and go. Don't accelerate hard until the temperature gauge is reading normal (warm).

In cold weather, you have to run the car for a few minutes in order to defrost and scrape the windows so you can see, but apart from that, it would be ok to start the car and drive off.

 

[rh71]

Warm it up enough that the RPM isn't above the usual 1100 at startup... usually drops to 700-800 after 30-60sec.

 

[bobross419]

Originally posted by: InflatableBuddha
No. As long as you don't beat on the car while the engine is still cold, with a fuel-injected vehicle, you can start it and go. Don't accelerate hard until the temperature gauge is reading normal (warm).

In cold weather, you have to run the car for a few minutes in order to defrost and scrape the windows so you can see, but apart from that, it would be ok to start the car and drive off.

This...

Also... idling wastes gas... 0 mpg

 

[sdifox]

depends on where you are. In cold places, you want to warm it up a bit, not just for the engine oil, but for the other crap in the engine bay.

 

[PhoKingGuy]

The VW manual says to not idle to warmup "for the sake of the environment" lol. But does recommend to drive carefully untill the engine reaches operating temperature

 

[BassBomb]

I just get out and go. Takes longer to wait for it to warm than driving it does to warm it up.

I just don't drive hard, you will realize even if you tried to drive hard you aren't getting anywhere faster.

 

[bruceb]

I agree. In very cold weather, a 2-3 minute warm up is the best idea. In summer / spring / fall, you can pretty much just start up and be off. Now on my car, I usually take a minute or so to get the radar detector up, clip the seat belt, crack the window if needed. Then I am on the way.

 

[Zenmervolt]

Yes and no.

Leave the car sit to warm up? Not necessary, though it can be nice when it's cold out and you want the interior to heat up.

However, you should give the car 10-30 seconds for oil pressure to stabilize before driving, and then go easy on the car until it has had a chance to warm up (usually 5 minutes or so). Heck, as far back as 1976 the owners manuals for my Porsche recommend starting the car and just driving gently until the engine is warm.

ZV

 

[Zenmervolt]

Originally posted by: bobross419

Originally posted by: InflatableBuddha
No. As long as you don't beat on the car while the engine is still cold, with a fuel-injected vehicle, you can start it and go. Don't accelerate hard until the temperature gauge is reading normal (warm).

In cold weather, you have to run the car for a few minutes in order to defrost and scrape the windows so you can see, but apart from that, it would be ok to start the car and drive off.

This...

Also... idling wastes gas... 0 mpg

Idling uses less than 1/2 gallon per hour for most cars. Letting the car idle for 5 minutes will have only the tiniest affect on mileage.

ZV

 

[Pacfanweb]

Variations of this debate have been on here several times.

Here's my take, and this is coming from over 20 years in the auto repair business, lots of schooling on it, etc. Plus, a long conversation with a Ford engineer about this very topic:

Disclaimer: I'm talking your average mild climates, not Alaska or Minnesota in the dead of winter.

You do not need to warm up your engine at all. You have oil pressure and oil is flowing to every part of the engine by the time it fires up and you physically remove your had from the ignition key. It's that fast.

Today's engines have much tighter tolerances. Why? Because the metallurgy is so much better. They have tighter clearances, because the metals don't expand as much.

Yes, that means that there isn't as much expansion....which means that warming up your engine really isn't doing much. You don't have .005-.007" piston-to-wall clearances anymore. (that's a lot, for you that don't know) Older engines with forged pistons still have that much, because they expand, a lot. That's it. Newer pistons don't. They are TIGHT. There is not much in the way of piston slap.

That's why all these awesome new oils help come into play. They are so "watery", even at low temperatures, that not only does it allow the tighter clearances, but they don't "get better at lubricating" when the oil is warm, either.

That used to be part of the reason to warm your engine....the oil didn't flow as well years and years ago.
So, you had oil that got really thick when cold, and engines that had lots of expansion as they warmed.
Both of these are greatly reduced.

Again, I'd still recommend you warm it a couple of minutes if you live in North Dakota. But you probably have a block heater if you live there, anyway.

Anywhere with a mild climate, fire it up and drive away. You're just wasting gas sitting there.

 

[Arkaign]

I would assume that 5w20 would be easier to pump than 5w30? My car recommends 5w20 (stock oil is Ford SynBlend 5w20), but I had an oil change will full-syn 5w30. Hope I'm not hurting the motor with this stuff.

 

[lurk3r]

My starter's still spinning when I put it in gear. I do use synthetic oil to make up for the abuse I put her thru though.

 

[DivideBYZero]

I drive immediately, but watch my oil temp and only give it full beans when it's up to normal running temp.

When I had a turbo car I did exactly this but also kept off boost until running temp. I normally stay under 3k rpm during warm up.

 

[LTC8K6]

I would assume that 5w20 would be easier to pump than 5w30? My car recommends 5w20 (stock oil is Ford SynBlend 5w20), but I had an oil change will full-syn 5w30. Hope I'm not hurting the motor with this stuff.

No. There's more to it than this, but basically the first number is cold viscosity and second number is hot viscosity. They are both 5W so they pump close to the same when cold. The 30 is slightly thicker when hot, so you are losing a bit of fuel economy.

Again, it's really more complicated than that, but you should really use what the mfg recommends.

 

[HardcoreRobot]

my car shifts really poorly when it is cold, so i usually let it warm up for a minute or two
edit - i mean, when it is cold outside. summertime no probs

 

[MovingTarget]

Well, fuel injection does help a lot along with other engine improvements we've had over the years. However, I would never just immedeately start driving a car from a cold start. Nobody immediately goes from turning the key to going straight into drive in one motion. I'd let my FI car idle for a little under a minute if it is really cold out, but wouldn't do any hard acceleration until it reached operating temp. My carb'ed car I let idle for a few minutes, as it runs rough otherwise when it is cold out.

 

[foghorn67]

Not in most climates. The combustion chambers are cold and even with smart computers and fuel injection, that fuel is washing oil down the cylinder walls. The best way to combat this is to put the car under load. A car idling even with a thermostat will take forever to warm up. Just wait a few seconds and drive lightly until at least the coolant temp is up to normal. Drive like normal when the coolant temp is up, but don't drive hard until a little bit after this since coolant temp does not equal engine temp.
For harsher climates, it takes time anyway to defrost windows and scrape ice off the windshields, and do what pops told you.

 

[DanTMWTMP]

i leave as soon as my car's idle rpm goes down (About 20-30 seconds). After that, I leave, drive easy until the temp guage goes up.

 

[LTC8K6]

Yep, quickest way to warm it up is to drive it. Idling it takes forever.

Driving it also warms up the other fluids as well at the same time. Tranny and diffs too.

Just take it easy until it's warmed up.

If you can't see because of snow or ice, that's what ice scrapers and deicer are for.