Mondrian

Problem with all the wisdom in either camp is lack of scientific testing (evidence), so all we really have is conventional wisdom & pseudo-science.

It is true that modern high performance engines are precision-built to much stricter tolerances than the engines of past decades which reduces the need for a long break-in period. However Motoman's logic is faulty in that his pool of evidence is based on the 300 odd engines he has tested majority of which were air-cooled motorcycle and snowmobile engines that are smaller & low cost which expand and contract more. Therefore it is highly unlikely that you would yield the same benefit (2-10% increase in power output according to him) out of a modern high performance car engine that has microfinished bores, high-tension rings, and precision-build tolerances resulting in excellent ring sealing from new. Of course power & economy will improve but that's due to the usual diminishing of friction in all moving parts.

For the record professional motor racing is a totally different ball game where engines are tuned for higher performances and accepting a lower life span, it's just not possible or feasible to run in the engine after each rebuilt.

I like to stick to middle of the road safe practices, avoid high revs & constant speeds for the first 1000-2000 miles depending on your self control - think of it as foreplay, it will make the eventual opening of valves that much more pleasurable, that's unless you are 18 in which case you could go down the road of wham bam thank you mam motoman route.

Cheekymonkeyman

+1 this is my approach.... Although I am saving Sport Plus mode as an 1800 mile treat (yes I am a Sport Plus virgin - 1200 miles so far )

I have a sympathy for all things mechanical... And helps me feel I am breaking it in gently... But that doesn't make it right necessarily

I'm afraid you won't get a definitive answer on this because there are many factors at play .... Some of which are in your control... And some of which aren't... (Tolerances, conformity Etc)

For me it was more about what helped my conscience than what helped my car... That's something I AM in control of

John's 991

In my opinion, I doubt that the car really needs much of a break in period. However, as I plan to keep mine for at least 5-10 years I broke it in per the manual, then took it to the track and really broke it in. There certainly can't be any harm in doing it, and the only thing you might lose is a bit of patience as 4k to 6k RPM is a lot of fun!

Harold1898

What is break in? It's a Porsche, drive the thing. I have never worried about "breaking in" since I visited the Kawasaki factory 35 years ago. Every engine is max revved for 4 hours then when they sell the motorbike they tell you to be soft and gentle for the first 1000 kms. I reckon it is a way out of spurious warranty claims from folk who race the thing straight out of the box.

enzom

As did mine. Drove it like it was meant to be driven right off the dealer lot. She has been strong since. If I waited for 2000 miles to go by, it would have been a 7 month wait on a 27 month lease.

LexVan

Days of past. Not anymore.

I have always followed the manual. Keep revs below 4,000 for the first 2,000 miles. Don't lug the engine. Vary the RPM's on long trips.

I always do an early oil change at the 1/2 way mark (1,000 miles)......another easy going 1,000 miles.......then let 'er rip.

Works for me. Not too hard to do.

chuck911

That's a good question. If every engine was run at full output, even just for several minutes of dyno testing, it would sure help a lot. If you take the time to read through my links (and there's a LOT more backing this up than just those two- they just happen to be the two best I'm aware of) then it should be apparent that the earliest few minutes and hours are much more important by far than anything that happens thereafter. Like the guy says in the airplane article, if the rings aren't seated at 10 hours, "it just isn't going to happen." (But I should probably not refer to him as a "guy" when according to the article he's Executive Director of the Cessna Pilot's Association and a 14,000 hr ATP rated pilot and A&P mechanic with inspection authorization.) Anyway, the answer is no, they aren't dyno'd at the factory. Well, not all of them anyway. Porsche does still pull and test a few, but good luck finding out how many or how they're run.

The dyno and testing questions do bring up a good point. Because if the factory truly honestly believes that hard early use is harmful, then aren't they damaging the engines they dyno or pull for testing? Hmm.

Porsche has rev-limiters to prevent engine damage. They have warning lights and instruments and codes up the kazoo alerting the driver to every relevant operating parameter. The car is so wired with safety shutoffs and warnings that you could spend a month searching RL trying to catalog the scores of codes that have sent owners scurrying back to the dealer. Yet somehow in all of that Porsche remains unable to so much as make a light flash if you exceed the fairy tale factory rev limit during the make believe break-in period. As Alice might well say, "curiouser and curiouser."

MJBird993

This thread is typical of what has become of Rennlist.

Forgive me for saying this OP, but did you even try to to read the manual that came with the car?

Mumbles

The only person who would care about breaking in an engine is one who has purchased the car, not leased the car.

Team Plutonium

I will never understand why people disregard the manual and ask random (anonymous) folks on a forum.

Duke I

Another question Chuck, in the narrative on the airplane engine break in, it seems to me that after the high-load interval of take off, the flight RPM (and load) would be fairly constant (whether in the first 30 min or second 2 hour flight). So applying this to a car engine break in, does this not suggest that it would be better to ramp up quickly to higher and a more constant RPM/load, then maintaining for good while? In contrast, the other link suggests repetitively ramping up and down RPMs and load. I'm trying to reconcile the two links.

clangpap

There are many threads on this and the opinions could not be more polarized. As I was picking up mine at the factory, I thought they should know what they were talking about, so I asked there.

I think his biggest point was not to just go for short drives in stop-and-go traffic, put on some real highway miles when you take it out, and vary the RPMs. He told me not to be afraid of hurting the car and to have fun, just show a little restraint over the first 500 km - I was there in the first day. I have to admit that was one of the big reasons for doing the ED, I knew I would have the opportunity to do long drives and have more fun in 2 weeks than I could in NA in six months.

chuck911

Back in the, uh, 1950's BF Skinner ran a series of experiments in which animals received either neutral, reinforcing or punishing responses to a particular behavior. While many people might think the best way of encouraging a behavior is with lots of nice fat juicy reinforcing rewards, it turns out the best and fastest method involves rewards randomly varied in both frequency and magnitude. Gambling, for example.

Or questions on an internet forum. More often than not they'll get answers that can vary from helpfully reinforcing to neutral to downright punishing. Every once in a while they get me and hit the jackpot. Like this one here, for example. More than makes up for the punishment of the last three before Dukes. And there you go.

perretar

Yes.

chuck911

There's less here to reconcile than it seems. While its all about engine load, there are also some very real-world limits on what we're able to do. The plane can fly all day at whatever throttle is set. The car though has to travel on a road. So sure it would be great to be able to load the car like the plane, but where you gonna find the road? A 991 is so aero it needs only a small percentage of its 400 hp to cruise at over 100 mph. It can climb even a steep 5% grade at over a hundred with just part throttle. So with the car there really is no choice but hard acceleration followed by braking, repeat, repeat, repeat. Which is why not all that long ago I recommended Stelvio. Some probably thought in jest. Nothing could be further from the truth.