Should You Warm Up Your Car Before Driving It?

The owners manual from my Land Rover Discovery, and the one from the Range Rover states the same thing. Wait for the idle speed to drop and off you go, keep your foot light until the needle moves on the instrument panel. Worries about engine wear? Change to synthetic oils.

Click and Clack recommend a warm-up period of "no more than a minute or two".

After that you're just wasting gas.

Do drive conservatively for the first few minutes, too. That's my recommendation.

My rule is to never pull away before the engine has started.

The concept of warming it up is complete hogwash...the engine is still running, the pistons are going up and down, the oil is circulating, it doesn't much care if it's connected to the wheels via the gearbox.
Ok I s'pose I'll reluctantly concede that if you immediately tried to drag a loaded skip uphill, it may put a slightly greater strain on the engine... but even then it's the first few seconds turning over with no oil pressure which would cause more harm.

Yes it's bollocks a fallacy in terms of engine care...different if you need to generate some warm air for your paws or to defrost/demist the windscreen.
It's a car for pity's sake ..it's there for your convenience not vice versa..stop petting and cleaning the damn thing...rant over.

Del

Your words are the voice of my heart...

In virtually every "modern" (i.e., post-1950) automotive engine, the oil is circulating throughout the engine within three to four seconds at the very most. (barring 50-weight oil in that old Studebaker up in Nome..)

Start it, put it in gear, and drive off. Easy the first mile or so, as suggested. Just have the oil recommended by the manufacturer, relative to your locale, in the engine and you'll be fine.

It depends on the car. Cars 10 years or older might benefit from a little warm up. I think anything younger you can just start and go, as long as you don't gun it. Also, I wouldn't define a day as "cold" for your car (thus requiring warming up) unless the temperature is below 25 Farenheit.

Current advice is no warm-up.

Since the 80's cars have been using thinner oil, which pumps faster at lower temps.

Most cars will use a 5w-30 at the heaviest, with some at 0w-20.

If you start the car, then fasten the belts, you should be ready to go.

Idling prolongs the warm-up, resulting in more condensation in the oil, as well as more fuel dilution, also in the oil. The cats also will not light up at idle either.

You also use a significant amount of fuel during a warm-up.

I'm in Wisconsin, and I haven't been warming up, even in a '77 Olds at -10F.

Though I went to 5w-40 synthetic.

Greetings.

If I remember correctly 90% of engine wear is in the first 10 seconds of operation.

Therefore either have an electric oil pump installed to bring the oil up to pressure in the whole system before starting or let the engine run for about 30 seconds so that oil gets to all the engine. Don't rev up a newly started engine.

Use a good synthetic oil in everything (engine, transmission, transfer case, differentials, and lubing). I use AMSOIL and don't sell it.

Some commercial equipment won't start until the oil pressure comes up to full pressure with an electric oil pump. This is an engineered design to prolong equipment life.

Agree w/ all said to date.

In addition to pumping up pressure before starting, pre-heating the contents of the sump & the engine + coolant can work wonders. Operating dimensions at startup, & reduced condensation, right from time zero.

Using waste heat from an inefficient mode of operation is rather poor.

Another reason to change over to synthetic lube (oil). Most folks don't care what the end result is of no warm up. Time is money. Fuel injection has made this easy and engine wear is traded away (never by a used car) without a thought. At least the new lubes will hold down (remember the commercial) engine wear at startup.

The days of letting the engine warm up went away with the sophisticated fuel injection systems being used today.

Remember always having to screw with the choke, flooding every now and then, etc

I guess these probably guys here now that have never had to rebuild a carburetor on the kitchen table???

Back in the 70's and early 80's, I had a side business rebuilding and setting up carburetors for mussel cars, (mostly Holly double pumpers). Talk about a useless skill today!

I had one of these:

Ya, with the 302

Setting up a Holly, through the entire RPM range, was more of a black art than science.

I still get a call once in a while to set one up, but no thank-you.

Fuel injection is light years ahead of any carburetor.

So many people have remote starters today. Push the button, the car is waiting for you all warmed up, with the heater cranking. It's all about having heat when you jump in.

Reallllll nice. It didnt like cold starts did it???

Some one told me long time ago, that rather than idling for a long time to get the engine warmed-up, it is better to start driving at a low speed (After allowing to idle for about 30 seconds so that the cylinder walls and crank bearings are coated with oil). Increase your speed as the engine gets warmed up.

You should start your engine and rev it to about 2000 rpm to splash oil onto the cylinder walls to provide lubrication to the rings and as soon as the oil pressure is up drive off with moderate acceleration.

People warm cars up so they don't have to get in a cold car or scrape the frost off the windshield.

This is ones own opinion, open for interpretation and there are many of these. Regardless of the oil, the engines simply would not run well until they had warmed up due to the lack of proper mixture or fuel injection.

There are other posters that say rev the engine to X RPM's. This is already programed into the equipment these days.

You can over engineer or over think it all you like, but with an open mind you will see it all changed with fuel injection.

As soon as the oil pressure is up to normal in any weather , you should drive of, treating the engine as if it is brand new.....do not let it idle, do not let it rev high, do not let it labour.[Losts of good reasons!]

If you really want your engine to last for ever......Add about 250ml of engine oil or 500ml of diesel to a normal tank-full of petrol...this is neccessary if you do short trips....on the long run, the engine should get enough piston ring lub through the engine beathing system from oil-gassing.[Engine starts easier, even uses less gas!][Common sence

This little amoumt of oil will do no harm to the catalitic exhaust system and the exhaust system will last 3x longer.

At 315,000 plus miles I wait for the oil pressure to come up and I go. Car manufactures have their own motivations and parts sales are one of their biggest incomes so I take a lot of what they say with a grain of salt.

The extra fuel/ RPMs are either time out or sensor dependant. You probably can't get 100% power right off the start until the brain box/computer finishes its start up loop.

During the startup loop, emissions are not a priority of the manufacture.

As for wear: valves, cams, rings are film oiled. unless the engine has set for a prolonged time the film will be sufficient for startup and a little more; The main bearings and cam bearings need more than a residual film to handle the pressures involved with high torque and high RPM. Once oil pressure is up they are fine.

One counter point is if you get a dry lobe on a cam you wear a very thin hardened surface in very little time. Many a cam is lost from rebuilding and not pre oiling the engine before startup.

Brad

U V -- All good points except on the oil draining issue.

I've taken apart stock engines with empty crankcases that haven't run in 20 or 30 years and there was still enough oil in the bearing clearances, cam lobes and even the cylinder walls to provide good enough lubrication to start up. The problems I see that are that often they need a little help building compression with a bit of oil in each cylinder, but not so much that it makes a mess of the spark plugs.

The other point is that if such an engine is a valuable high performance engine with heavy valve spring loadings I'd want to pull the oil pan, check the insides, put some prelube grease on the cam lobes and a give a few hand turns of the crank watching the valve action for signs of distress.

Ed Weldon

Very true Ed,

The thing I find is most modern engines fall under a high performance of the 70's, at least in part. Valve loading and RPM was much lower in the early 80's and before. Materials have made large improvements in output and design tolerances.

I have changed worn tappets in a 67 strait 6 with out to much worry about the cam. Something I would have to do some serious checking before attempting in a new engine.

On the other hand modern oils have much better properties. The cheap ones would need to be changed right away if they sat in an engine for a long time. The Additive package would be a coating in the pan and the base viscosity index is not very good. The additives will still settle out of the better oils over time but base oil is a much better lubricant.

Brad

I seem to remember there were some GM engines back in the 60's and 70's, mostly V8 small blocks that had problems with cam wear. IIRC the 30-30 Duntov cams of the "60's" were not in that category.

Ed Weldon

Ed,

Are you aware if the '67 283 V8 small block fell into that category? I have one that I'll be rebuilding this spring.

G'day frankd20, you've received some good advice hear, take it. The only thing I can add is remember your oil pressure is at its lowest at idle. Gentle driving will bring this up to normal and will warm you car up quicker too.

RRV

Get a house with a garage. Problem solved.

One thing for sure, the greeniest thing to do to heat up your engine when it is very cold (-20°C and lower) is to use an electric block heater for about an hour before starting the engine.

Electricity does not magically appear at the wall socket. It is either produced hydroelectrically by flooding a whole lot of wildlife habitat or by nuclear with a great deal of radioactive waste or by coal-fired plants. No need to discuss the harmful effects to the planet with coal-fired is there?

Yes, please plug your car in at night this is very green and helpful for the environment.

UFG

So I guess you have a "green" garage that keeps your stuff warm then????

Quote Tim: "So I guess you have a "green" garage that keeps your stuff warm then????"

YES!! HOT IDEA! 12x24x10 reinforced concrete box garage inside a manure pile. Just make sure the car windows stay closed.

That's not a bad smell, Son. That's the smell of money.

Ed Weldon

Let me know when you get snow in Mexico and then you can make fun of me.

LOL fair enough... But I wasnt always so lucky, many of nasty winters in Baltimore

One important safety consideration has been missing in all the discussions I've read about whether it is best to warm up a car in cold weather. Years ago, my father-in-law started his car after working 2nd shift on a cold winter evening (-15 to -20 F). He let it warm up a few minutes, then pulled onto the highway. As he went up a steep winding hill with deep ditches, the windshield suddenly frosted over. The frost inside the air ducts suddenly melted and the moisture was immediately deposited onto the inside of the sub-freezing windshield. He couldn't see a thing and went down the deep ditch, totaled the car, broke his neck, and nearly died. He eventually recovered.

I live on a highway with a posted speed limit of 55 mph, so traffic usually travels 60-70 mph. When I pull onto the highway, unless it's early Sunday morning or after midnight, I usually have to step on the accelerator hard to keep from being hit. I have also had my windshield suddenly frost over when the temperature outside was cold, -10 to -30 F, if I didn't let the vehicle warm up adequately first.

For the vast majority of modern vehicles in most circumstances, it is probably not necessary to warm up the vehicle to prevent damage. But in certain circumstances, like temperatures below -10 or -15 F and having to pull out directly onto a busy highway, warming up the vehicle can prevent catastrophic results, including total destruction of the vehicle and severe injury, or even death.

So it appears to me the overall best thing to do, (If you live in a very cold climate). Would be to install a block heater and keep your vehicle protected in a garage if you can...

1. Obvious mechanical reasons.
2. Comfort (quick heat).
3. Safety, sort of goes hand in hand with 1 & 2.