Engine Break-in

Patman said:
I think that the “not going over 55” rule doesn’t really apply anymore ever since overdrive transmissions became a thing a few decades ago. In the pre overdrive era you would often end up having your engine at 3000 rpm at 60mph, especially if you were running shorter gear sets like 3.73s, 4.10s etc. But these days there are cars like my Vette which has an 8 speed automatic and 2.41 gears so I can go 100 mph in 8th gear and the engine is only at 2000 rpm.
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That makes sense. My 4cyl diesels are pretty high rpms on the highway.

ecotourist said:
When I was an undergraduate student in mechanical engineering (late '60s, early '70s) one of our profs told us that a hard break-in made for a better engine. Myth?
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That has always been one of the theories. There is a motorcycle site that pushed that. I think what was established some time ago was that you really wanted coating down to force the rings to seat. Of course, lots of industrial engines aren’t run or operated that way with that opportunity…

Corollaman said:
What about the thousands of new rental cars that never receive any type of special break in? I've owned several ex rental cars that never had any mechanical issues that I'm sure were never "broken in".
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The use profile may naturally achieve that to an extent.

f355spider said:
Maybe. On Ferrari forums people often ask about break-in (there are specifics in the owners manuals) yet all new Ferraris arrive with anything from 30 to 80 or more miles as they are shaken down at the factory around Maranello by their test drivers. According to those that have seen them out driving, they are not babied and get hammered pretty good...so they kinda laugh at Ferrari's break-in recommendations. :)
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I wonder how long those engines actually go before an overhaul or major service. How many actually get any practical miles at all? I saw an F40 and F50 for auction recently, super low miles. It’s not like they’re cruising the interstates….
 
JHZR2 said:
I wonder how long those engines actually go before an overhaul or major service. How many actually get any practical miles at all? I saw an F40 and F50 for auction recently, super low miles. It’s not like they’re cruising the interstates….
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Like anything, "it depends", but there are many that accumulate a lot of miles these days. "Super cars" like the Enzo, La Ferrari, F50s, those that trade in the 7 figures are rarely driven, because they are special, and production limited to several hundred.

But, Ferrari has evolved in the past 25 years to add creature comforts and make the cars capable of being daily driven. Their cars from the 70s and 80s really weren't capable, just due to more frequent service intervals, and lack of decent AC or ergonomics. Even in the 90s, it may not have been...though I owned a 97 F355 Spider, it would have been possible. I doubt I could with my previously owned 78 308GTS or 87 328GTS.

Since around 2005 or so, Ferrari eliminated timing belts and went to chains. In 2013 they started a 7 year free maintenance program for all new cars sold. They are encouraging people to drive and enjoy the cars, and not worry about miles and maintenance.

I have friends and acquaintances with high mileage Ferraris..one has a 2013 F458 with over 135,000 miles. Others with high five figures on miles and these are all newer cars...I sold my F355 over a decade ago and it had over 60k miles at the time.
 
If you can not do a full power run by flooring the thing in a reasonable 2+ second time (not even close to slamming it to the floor) you never willbe. One hard 10 second will not build up excessive heat. Any mechanical engineer {not limiting it to a M.W.] that knows engines will understand this.

Breaks are a whole another matter.
 
Al said:
If you can not do a full power run by flooring the thing in a reasonable 2+ second time (not even close to slamming it to the floor) you never willbe. One hard 10 second will not build up excessive heat. Any mechanical engineer {not limiting it to a M.W.] that knows engines will understand this.

Breaks are a whole another matter.
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I’m not sure what that actually means.

Sure, it should be able to handle it. Sure it’s not that much excess heat given the heat capacity of all the components.

For a new engine the consideration would be more along the line of asperities in sliding surfaces and in certain bearings, which could undergo different motions and alignments under hard use, which could have other effects.

In the end it’s your machine and money, and your outcome.

And it seems that nobody really knows.

But I’ve seen more OE guidance for breaking in gently than not.
 
YES, I break in my cars, truck, motorcycles per the book! and then some. I try and do some heat cycles, keep the rpms down under 4k, NO steady speeds the first 600 miles but I load up the pistons with acceleration then deccel to load the rings.

On all my Harleys the last 30 years I do a early 100 mile factory oil dump refill with 100% Mineral dump again at 500 miles and dump again at 1K and run normal oil.
Lawn mowers dump the oil after first grass cut.
I did this in my now old then new 1997 Harley and does not use a drop of oil now 29 years later.
I also teach my kids and wife how to proper break-in a new car
 
I have two vehicles I purchased new so both broken in by me. The first is an '03 VW GTI 1.8t that I followed the factory recommendations for break in as far as engine rpms go, but I remember changing the oil at 1000 miles. At 178k now and has never consumed any measurable amount of oil between changes.

The second is a Kawasaki Z125 pro air cooled 4 speed mini motorcycle. That got a hard break in. Right out of the parking lot I had it pretty high in the rpms just to safely pull out onto the busy road the dealer was on. Lots of medium high revs and engine braking on the mix of main and backroads on the ride home. I changed the oil and filter 3 times in the first 1000 miles. The first right when I got home, once at 500, then again at 1k. It's got 15k now and runs great with no oil consumption.
 
I'd say one thing has changed between a car made ten years ago vs one made 5 years ago and more recent - the perverting effect of many-many-many gears.

My 2016 Santa Fe has a 6-speed transmission and still tries its best to keep the engine under 2000rpm, no matter what, at all times, except in sport mode where it's only slightly better. And which has to be engaged every time the engine is stopped, as it doesn't remember it (it does remember Eco mode of course. But not Sport).

The loaner I am currently driving is at borderline idle most of the time in normal traffic. Eight gears.
The Honda Pilot was frequently crucified during test in its 10-speed version (when they were starting the 10-speed and it was only available in the expensive models).

Driving in a "healthy" rpm zone for extended amounts of time im modern vehicles is a deliberate process. It doesn't come and can't come naturally. It has to be pushed for.

So for vehicles just bought and driven by people in congested suburbia, some of these engines never ever see any revving at all.
 
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