We have a debate going at work; settle the argument for me…
I was taught in high school engine shop (about 15 years ago) that the absolute worst thing you can do to your engine is start it. There is no oil in the top end (valves) and the pistons, as it all drains into the oil pan. My shop teacher said, “I don’t push my engine until it’s fairly warmed up, it saves wear and tear.” He went on to say that the oil, while formulated to stay thin when cold, still isn’t as thin as it should be until operating temperature. Also, there are alot of metal parts that aren’t in tolerance until the metal parts warm up and expand (the pushrod/valve connection, and the piston/cylinder walls, for example). Therefore, I don’t let my rpm’s get too high until my engine warms up pretty good.
My buddies argue that modern engines don’t need to be warmed up and you can just fire them up and go! New engines and oils are just fine to rev high before they are up to operating temps.
This makes for an interesting drive home from work. While I oooooze out of the parking lot (because my engine isn’t warm yet), these guys are flooring it to get out of the parking lot ASAP! Needless to say, they get ticked when they get behind me. I just figure that I’m taking care of my investment.
You both are. The wear and tear on the engine does happen, but to such a degree that it doesn’t make much of a difference in the overall life of the engine. It won’t die an early death if you rip on out of the parking lot with the rest of the gang.
Modern engines and modern engine oils that we have now make it such that even if you do not allow time for the engine to warm up before putting it under load, it’s likely still to last for the “effective life” of the car quite well. Yes, it goes against the grain to push a cold engine, and I never do myself.
An older car, even when new, would accumulate more long-term damage quickly. I wish I could find a study done by the SAE that I had here, where they found that cars “driven hard”, but well-maintained with oil changes and tuneups at the recommended intervals, had no statistically significant difference in engine wear at 40,000 and at 80,000 miles.
However, IIRC, they did see a noticeable difference in wear and engine performance with the engines when they took them to 120,000 miles.
The conclusions you can draw from my anecdote, which I have no cite to back up (until I can locate the study…I’ll look at work for it), is that if your car is a “100,000 mile and trade it in” car, don’t worry so much as long as it is well-maintained. If it is a “drive it 'till it drops” car, then do worry about it.
I don’t know where you live, but if you get even mildly cold winters you should definitely give the engine time to warm. If you get insane, Nordic-Hell subzero winters, get a block heater.
You will most certainly get more life out of your car if you treat it properly, and that includes making sure your lubricant has time to heat up, lose some maple-syrup viscosity, and get where it needs to go.
Yes, the worst wear tends to be during cold engine start-up and warm-up. While the mileage figures mentioned by Anthracite may be correct, bear in mind that with modern cars it is shocking if an engine doesn’t make it to 100,000 miles. The overwhelming majority will easily hit 150-200k with reasonable care and maintenance.
The cars of yesteryear had carburetors, which were often tempermental when cold, and usually HAD to be warmed up some so as not to stall or run like dog turds. Modern cars, which have fuel injection, are drivable essentially immediately after starting, even in cold weather, due to the relative precision of electronic control systems (the “computer”). The general recommendation I hear is to not warm them up before driving, but drive right off, going GENTLY until they’re at least somewhat warmed up. This is usually followed with a statement about how it wastes fuel to let the engine run without accomplishing any travel.
My opinion is, screw the fuel issue, I’m not going to suffer and shiver in a cold car if I can avoid it. Whenever possible, I warm the car up to get some heat. However, I’m not concerned about driving with a cold engine so long as it’s driven GENTLY. Those who drive a cold engine vigorously are shortening its life. I think your buddies are confusing drivability with longevity.
I’m an auto repair professional with nearly 30 years experience.
There are a few aftermarket devices for sale that pre-pressurizes the lubrication system in your engine (electric oil pumps, oil
reservoir with compressed air, etc.). Use one of these and your engine will last FOREVER.
if you are paranoid about engine wear on starting, use a third party product like Slick 50 or Nulon.
These are added when you change oil and are circulated with a running engine for about half an hour. What they do is deposit a microthin film of Teflon to all surfaces that the oil contacts, thus reducing friction and wear. Hence there is some protection in place when the engine is stone cold and all the oil is in the sump.
One application is supposed to good for about 80000 kilometres.
I think it’s important to distinguish start up from warmup .
I heard that 90% of wear happens during startup, because the fluids have drained back into their reservoirs. The first few cranks are metal on metal (almost).
But that all changes in just a couple of seconds. Yes, cold oil is less effective than warm oil (to a point), but it will still work as a barrier between moving parts like it’s supposed to on all but the coldest days.
So I just start, and drive away as soon as the engine is at a smooth idle, except when I want the heat to crank for a while for my comfort. And that’s what my owner’s manual recommends.
It would make more sense to measure the lifespan of engines in expected starts rather then expected miles.
I doubt this. Motor oil has the inate quality of wetting and clinging to dry surfaces. In addition, additive chemicals augment these inate qualities. Before a new engine is started all surfaces are coated with lubricant and that lubricant stays there during the life of the engine.
I can’t find a cite for it, but many years ago the Post Office Department conducted a test. Vehicles were chosen at random. Half of them placarded that they must be warmed up before driving and half just started and went. At the end of the test there was no statistically significant difference in maintenance required during the test or in life of the engines between overhauls.
And, of course, if most of the wear occurs during start-up then all engines wear equally. They are all started cold most of the time.
Unfortunatley these additives don’t work. From the U.S. Federal Trade Commission site, QUAKER STATE SUBSIDIARIES SETTLE FTC CHARGES AGAINST SLICK 50. I couldn’t find anything on Nulon on the net, but that may have more to do with its being an Aussie product. Apparently it’s a teflon-based product, same as Slick-50.
I remember reading about that study, too. And the Click and Clack guys (I think their site is www.cartalk.com) recently said that modern cars do not have to be warmed up before being driven, but to drive them slowly until they are warmed up. Whether you’re warmed up and whether that’s important to you, is another story.
I’ve got to second cornflakes here. Most aftermarket oil additives are pointless at best and potentially harmful at worst. No confirmed, independent study has shown any benefit from these additives whatsoever. In fact, some studies have shown that the potential exists for the small particles of PTFE to clump and clog the oil passages in the engine. This would lead to increased engine wear.
Here is a link to an articles that sums up the arguements against additives nicely: http://www.dieselsite.com/prodrev/snakeoil.htm
The main thing to consider here is that the only entities who claim any benefit from these additives are the same ones who are trying to sell them to you.
Well, that depends on how you warm the car up. I live in Minnesota and when I leave work there a several people sitting in a freezing car waiting for it to warm up. They claim they want to be warm driving home (Huh?). A car will warm up faster while you are driving and you will be well on your way home when heat starts coming out. These people that just sit there are freezing their @#% off and they still haven’t started for home.
Swede Hollow, you’re right, if someone’s going to be in the car anyway, they might as well be driving it. I let in run in the garage or driveway, temperature control to maximum heat, heater fan on low, while I’m comfortable inside the house.
Whenever I do this, the car is LOCKED and within my sight and/or hearing, so I would know if someone tried to steal it. It always amazes me to hear of cars stolen while being warmed up outside–and NOT LOCKED!. You gotta wonder if these folks ever even thought about the cost of a set of keys ($3-5) compared to the expense and aggravation of having a car stolen.
For what it’s worth, I ALWAYS carry a second set of car and house keys. If you’ve ever dropped keys in deep snow, or absent-mindedly locked keys in the car, you can appreciate the benefits of this. Of course, my being a guy, these keys are on my person, not in a purse that’s likely to be locked in the car next to the keys that are in the ignition.
Oil additives like Slick 50 and Duralube etc. are complete and utter bullsh*t. They should be called ‘Engine Wear-Outer’ or ‘Motor Blowup-er’.
Instead of ‘coating the metal surfaces with teflon’ what they end up doing is clogging the oil passages with teflon and starving parts of the engine of oil causing premature wear.
For a while DuPont actually refused to sell teflon to the company that makes Slick 50 because they knew it was not a good thing to put in motor oil and felt it would give them a bad reputation (Teflon™ is a DuPont trademark). A judge later ruled that it was illegal for them to do this (restraint of trade or something).
I didn’t say anything about super-slick oils, or after-market additives or other market gimicks. Ordinary motor oils contain wetting agents and additives to improve the “cling” quality in addition to chemicals to counter the buildup of acids and other contaminating products of combustion. Motor oil isn’t just petroleum and hasn’t been for a long, long time.
Most cars today may be driven safely almost immediately upon start up. In fact, driving them is the preferred way to warm them up. At idle most warm up too slowly.
That said. It is best to keep the RPM well under the warm maximum while the engine is still cold.
Some of the BMWs available today move the redline down on the TACH when the engine is cold. As the engine warms up, the redline gradually moves up to it normal point.
Don’t have that nifty trick on your car? Good rule of thumb. If the engine is very cold, don’t exceed half the indicated redline rpm. Once the engine temp gauge is off the bottom peg, you may use up to 2/3 max rpm. Once the engine is at normal temp, use it all (if you are so inclined).