OK, Chicago and NJ, that makes sense. I would like to move south myself. I've seen enough snow and cold. I'm sure your cold days don't last long.

 

With all due respect to Labnerd you live in Texas. You probably don't deal with cold weather like some of us do.

My advise to the OP is it to take a bottle of the oil you use in your truck and subject it to -30 degrees C or -22 degrees F overnight then try and pour it out of the bottle. If you still want to fire up your truck and pull away in 30 seconds feel free. I will warm mine up 5 or 10 minutes in extreme cold.

 

With all due respect, the experience and knowledge that you bring to this discussion is that you've poured oil in your vehicle on a cold day, and you think that trumps labnerd. Now that's bold. I enjoy reading his comments because of his extensive knowledge.

I've never poured a bottle of oil below -20. Tried it once, and decided it was too cold to wait that long for the oil to pour out. I put the cap back on the bottle an drove home. I know, when it's that cold, you can tip the bottle upside down for a matter of seconds, and not spill a drop of oil.

You get a lot of wild opinions stated as fact in these forums. One says our engine will be toast in 15 seconds without oil, and the next says some oils can take up to 25 minutes to reach all areas of the engine. Which is right? Are they both in error?

While I'm no expert on the subject, I think I understand what happens, and why it varies quite a bit. I've seen a video of an engine that ran for almost an hour without oil, and I've seen some stop in seconds. Oil does two things, suspends metal parts, and cools the engine. When you drain the oil, you don't get all the oil out, it's sticks to all surfaces, coating them in a thin layer of oil. That may be all the oil the engine needs, after all, that is how a two cycle gets lubricated, just a thin layer of oil is all it gets.

It's all about film strength. When you drain the oil, you still have film strength, and colder oil is has more film strength, so think of how hard it would be for two engine parts to squeeze the oil out from between them at -30. The problem with draining the oil is that you lose the ability to cool those parts, and as they heat up, that thin layer of oil loses film strength, which results in heat causing friction. That being the case, it's reasonable that a cold engine will run longer after draining out the oil than a warm engine, and and engine without oil will idle longer than it will run under load or WOT. That being the case, if you drain the oil on a cold engine and then turn the key, it may idle for an hour, while on the other hand, busting the oil pan while pulling a trailer up hill on a hot day could be a disaster seconds after the oil gauge goes red. We can also say that when you start an engine at -30, film strength is not the biggest problem that engine faces.

 

I am not trying to trump anyone as you put it. I assumed this forum was for stating ones opinion or experiences. I stated mine based on 25 years or so of twisting wrenches on my own and my friends vehicles. I also live in a cold climate and have done so all my life. You rarely see anyone start their car and pull away in 30 seconds in extreme cold around here. We must all be wrong.

 

Interesting discussion here, a real good read. Even still, when it's below 20 degrees or so in the morning, damn right, I'm warming my car,truck,whatever up every time. I've done so for years and I'll continue to keep doing so. I think this subject is a bit over analyzed, but that's just me. I don't deny the fact that it's not needed for the vehicle, but it damn sure is needed for me on a cold morning! lol

 

Rather its right, wrong or indifferent I will continue to start my cars and let them warm up on colds mornings if one of two things happen. One being I have ice on the windshield or two my children are getting in the car.

 

This has been interesting, good to here different opinions from everyone.

 

I have had to start and drive my truck in -45c (-50f) without the wind, no block heater or anything. It turned over so slow I thought it wasn't gonna start. My power steering pump whined for about an hour and normally it will only whine below -25f. Yes I let my vehicle warm up in the winter nobody on here can convince me otherwise. There is no way letting your vehicle warm up for 5 minutes in the morning is gonna hurt anything. In the summer I wait till the idle drops below 1000rpm

 

I guess parking my truck in a garage makes a difference in my 'warm up' procedure..

Sucks to be you if you are in a sub zero degree temp zone.... I'd let it warm up too if that was my case....

Mitch

 

Hypereutectic pistons. Today's engineering wonder. They hardley expand when warmed up, unlike forged pistons that need a good amount of time to expand. These trucks are mention to be started and driven. They aren't supercars with delicate internals that needto be warmed up before driving. Fords engineers were looking at the average joe who needs to get in his or her truck and go. Oil pressure peaks around 30-45 seconds of engine start. So ur pretty good after that. Just listen to your engine when u start it as soon as the computer idles down u have oil pressure. Just don't bring it up to peak rpm and it will be fine till it warms up.

 

Can most of us agree on this? There is no harm in driving off after a 30 second warmup, but if you want to do a 5 minute warmup for driver/passenger comfort you really aren't hurting anything as long as you actually DRIVE the thing often enough to burn off the fuel dilution in the oil?

 

Yup.

 

No. You assume that the fuel stays separate from the oil and burns off as the engine heats up. It does not. Think a minute glc, I know you are fairly sharp about engines and oil. Both oil and gas are hydrocarbons from the same base source. When mixed together, they stay mixed together. You'll burn off the aromatics in the fuel after several hours of driving after one cold startup and letting it idle but you'll never burn off all of the fuel hydrocarbons. That's why you'll see the fuel in oil analysis. It's for this same reason that you'll find that an oil is said to shear out of range during the winter months. It's not necessarily shearing but dilution depending on how much fuel has actually gotten dumped into the oil vs actual shearing. And remember the specs on a 945 or 930 oil while thinking about this. And remember the old days of using a heavier oil when towing? It wasn't that the engine built more heat and needed it. You used it because the carbs were notorious for dumping fuel into the combustion chamber where not all of it was burnt and you ended up with loads of gas in the oil reducing actual viscosity. It did not burn off like you think otherwise, we would not have seen folks changing motor oil at 3000 miles. The days of carbs are gone but the 3000 mile oil change lives on which is a waste.

A lot of you posted opinions and your certainly welcome to an opinion but I posted facts. It's your engine, your money, drive it how you like but the original poster asked a question and I answered it with facts, not an opinion. And I could give you even more facts about the forces causing varnish and sludge that are more prevalent in a slow to warm engine than a quickly warmed engine. But no one seems interested in facts anymore.

 

No Labnerd, I always like reading posts from you cause you always seem to state facts. Also from you GLC. I'm enjoying reading this thread so far. I was always taught to let it idle before taking off but ever since I started this thread I've been letting the idle drop then I go. I never go about 2000 RPMs so I guess I'm ok anyways.

 

Consider this, I'm thinking "out loud" here. your commute to work is approximately 15 mins each way. If you let it warm up that extra 5 mins before you jump in and go would you not help it burn off condensation that accumulates inside the engine.

Also Wouldn't the fuel dilution help in the fight against engine sludge because the gas breaks down the oil?