New Car Break-in

Hello all,
I was finally able to purchase a new car, and I heard from people that there is a break-in period where you have to drive it at different speeds for the first 1,000 miles or so. I know this is true for older cars. But is it really necessary for cars now days?
Thank You!

Look in the car’s owner’s manual. Don’t only look in the owner’s manual for that information. Look through the entire thing. Many of the questions that you have about the car are answered in there - including this one. If it doesn’t say anything at all I’d just drive it…however you drive it.

The most important thing is to vary the engine speed, and not to drive at a constant speed for at least the first 500 miles. In other words, make believe that the cruise control does not exist, and make a conscious effort to vary your speed by a few hundred RPMs every few minutes. Essentially, that is it, but as cigroller suggested, you should DEFINITELY read the entire Owner’s Manual. Begin with the section on engine break-in, and then expand your reading over the next few days to cover the entire manual. Don’t be afraid to re-read parts of it periodically, in order to refamiliarize yourself with technical points and maintenance details.

Incidentally, Honda does not recommend early oil changes with their new cars, so forget about the old “1,000 mile oil change in order to get metal fragments out of the engine”. Apparently, Honda’s crankcases are filled with a special formulation oil that should be left in for the entire duration specified in the maintenance schedule.

After that initial oil change, feel free to change the oil more often than specified if your driving conditions warrant it. In the section devoted to the maintenance schedule, be sure to read Honda’s definition of “Severe Service”. More often than not, the way that most cars are driven actually puts them into this category, which mandates service more often than the “normal” maintenance schedule.

Besides Cigroller’s and VDC’s comments, I would check the oil level frequently during the break-in and regularly afterwards. The Owner’s manual for my wife’s 06 Toyota Sienna mentioned the possibility of oil consumption (1Qt/1000m) during the break-in period.

Ed B.

Most new cars do not require a break in any more, it’s just start and go. I think it has too do with much improved production techniques.

I bought a new car in 1995. I did not break it in properly, traveling the interstate at a constant speed under cruise control every day.

I still have that car. It has been my daily driver ever since. It has 260k miles on the odometer and it still runs strong. So don’t worry too much about babying your car with a prescribed break-in procedure. Just drive using your normal habits.

What does your owner’s manual say?

By the way, Honda typically uses a break-in oil that shouldn’t be changed early. If that’s what your owner’s manual says, I’d recommend following those instructions.

Yeah, the first thing you should do is scan the owners manual when you get home. There will be some break in precaution to not strain the engine for the first 2-500 miles and vary the speed. I couldn’t stand to leave my oil in for 5000 so talked to the dealer and changed it at 2000. There’s no problem changing it after the first couple of thousand or waiting until the first 5000. Here we go again but no way would I wait for the 7500 miles that the OLM will tell you.

Most new car’s manuals will tell you not to drive at high speeds, or for long periods at one speed for the first 500- 1000 miles. Also, you should take it easy on the brakes by not making quick stops or riding them. Not just because it’s a new car, but because they should be treated like any new brakes

The best thing to do is just use common sense. Like anything brand new you shouldn’t do anything excessive, like speeding and braking quickly.

Personally, I’ve always considered how much I’ve invested in my new car and drive it very carefully ALL THE TIME.

It pays off in the long run if you drive your car carefully and always maintain it as recommended in the vehicle’s maintenance manual.

Bing wrote:
There’s no problem changing it after the first couple of thousand or waiting until the first 5000.

Honda goes to the trouble of adding a special additive and specifically telling the owner not to change it early. I’m afraid I trust their engineers more than someone on an Internet message board on this point.

The engine is broken in within 20 miles. Any statement in the manual about operation in the first 1000 miles or so is done as kind of cautionary insurance policy to prevent people from flogging them into the pavement and possibly causing a problem. This of course would lead to a demand for a warranty repair at the car maker’s expense.

Automotive engineers say a lot of things; some of it dead on and some of it utter garbage. Auto mechanics are usually wrestling with engineering screwups or problems due to their hokum advice on a regular basis.
In fact, many mechanics would like to take a fair number of those engineers out behind the woodshed and try to extract a coherent answer as to why they recommended or designed this or that.

Is it the automotive engineers that the mechanics would like to take out to the woodshed?

In many places I’ve worked, the engineers want to communicate the simple facts, but upper management and the bean counters force them to modify the message.

In the same manner as I would refer to an architect or structural engineer vs a carpenter regarding the required structural integrity of a beam, I would trust the engineers who designed the car over someone trained to service/fix them. Two completely different skill sets and level of expertise…

This question will continue to be asked Ad Infinitum Ad Nauseum…and no one will ever agree with the all the answers.

But look at it as though you were a new machine…how would you want to be treated until you could get a micro-polish on all your rotating assys? Run Hard…Balls to the walls…? Or gently or at least thoughtfully broken in till all the parts get to “know each other”? There is more than enough evidence to support the gentler method than supports the former…and that’s a fact

I am of the Kinder Gentler method meself…prob because I have actually tried to machine parts before…BY HAND…on a mill…gives you a whole new window on Tolerance…

Ever see the surface of a crank journal under a microscope Prior to assembly compared to one that has been spun 5000 miles? Quite a difference…AND all the contact surfaces perfectly match the rotating assy at that point…there are no more differences they are all “mated up”…its kinda cool


I wouldn’t drive a car like I stole it but just drive it the way you’d normally drive it – unless you normally drive a car like you stole it. Varying the speeds is often what the manual suggests so just stick to what the designers suggest in the manual.

Years ago they required cars to stay under 50 for the first 500, along with an oil change at 500 miles. Those days are gone.

Common sense prevails in “breaking in” a car. Normal city driving is good while avoiding jackrabbit takeoffs. Agree that the rings should be well seated in about 1000 miles.

The things to avoid according to most manuals are heavy loading on the engine (trailer towing), and driving at one speed for an extended period. Toyota recommends avoiding these, but also accelerating fast every now and then to cause a very slight amount of wear to seat the rings properly.

I’ve done all the above with my Toyota and after 5 years have never had to add any oil between the 5000 mile changes.

Mr. Wakaflaka218,

As was said, new engine break-in is not nearly as critical as it was in the past. The reason for this is because modern machine tools, cutting bits and cutting lubricants have advanced to where the surface finishes inside your new engine, especially for the cylinder bores, pistons and piston rings are close to what they will be after break-in.

There may also be some additional surface treatment methods used to get what is wanted by designers, a new engine that is as insensitive as possible under widely varying treatment among new car owners who may have widely varying opinions on break-in in spite of lack of experience designing and testing engines along with the refusal by some to read or obey the owner’s manual.

Actually, I agree with Joe Mario about bean counters and the marketing department overriding the engineers.
The example that always comes to my mind is the Ford TFI module problem and ensuing class action lawsuit.
It was revealed in memos that the engineers felt these modules were problematic due to heat failure but management, faced with the choice of going full speed ahead or writing off who knows how many man hours of engineering, baskets of cash, and a re-engineering job, chose the go with the former.

I do think engineers create bad designs and make bad recommendations though. Early Subaru shifter shaft seal problems and brake caliper yoke design led to beau coup problems.

If the bean counters and marketers are the ones making the recommendations then listening to the people who actually manufactured the car is not the wisest thing to do.
An engineer who is constantly having his designs overruled and revamped and which in turn causes mechanical problems, or even personal injury, should resign his position and engineer somewhere else.

There are more things than the engine that need to “break-in” on a new vehicle. The transmission along with the entire driveline break in as well. However, I do agree that this probably occurs within the first twenty miles. In the old days, we used to worry about the piston rings seating properly. I remember back in 1953 when Buick introduced a new V-8 engines, Buick had some oil consumption complaints. Apparently, those engines in some cases took 4000 miles before the rings seated and the oil consumption diminished. Buick did make a running change to a piston ring that did not require as long a period of time to break in. However, once these engines were broken in, they seemed to run forever.
I have thought about small engines. I’ve never broken in a lawnmower engine. I just fill the crankcase with oil, pour in some gasoline and start mowing.

Triedaq, when was the last time you had to put the hammer down on that lawnmower to merge onto your lawn? Been towing any campers with it? Curious, do you tend to start it and go because you can’t wait for the heat to kick in when it’s 20 below? :slight_smile: Small engines tend to run under a particular set of conditions and fairly light loads and they tend to come up to operating temp pretty quickly…

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