991Dreamer

This is all very entertaining but let's please not forget about those of us who look to the forum for advice and guideance from people more knowledgeable. As a soon to be new 991 owner I can't help but think, after reading what's been posted on the subject, "WTF AM I SUPPOSE TO DO?" I want to do what's best for my new engine to ensure a long productive life and I get the whole lawyer thing with the Porsche recommendations, but crap.
Am I wrong in seeing that the argument seems to be what Porsche says to do versus what people who have at least some empirical evidence that points to running your new engine hard say to do? Or is it just a matter of let's all agree to disagree?

rpilot

The Porsche Manual is your best friend. Period. Don't worry about the rest. You are not going to track the car like you said, and you don't have race to win in the first 2K miles. I don't see a problem here, unless you want to create one for yourself.

John 996 TT Cab

Over the past 40 years of Porsche ownership I've been lucky enough to be in the position to break in 9 Porsche engines in new cars. My cars, according to the Porsche service technicians always have performed as if they had 10 to 20 more hp than most.

For my new 991S Cab X51 my plans are for the first 4-500 miles I plan on keeping to the recommended 4200 rpm or close to that. For the next and up to the 2000 miles the car will experience short bursts up to 5000 rpm for about 500 miles, then 5500 rpm for another 500 miles and then 6000 rpm for the last 500 miles of breakin time. These will be short accelration bursts and not continuous driving.

At no time will the engine be allowed to "lug".

I would expect my rpm while driving will be between 2500 and the above noted rpm numbers until the 2000 miles are reached.

Mike in CA

Can't blame you in the least, Gary......

Mike in CA

A quick search around "break-in" will reveal that there are dozens of threads and hundreds of pages on this subject with all of the information and POV's you could possibly want. If you read through those threads you may conclude, as I have, that the "empirical evidence" is often unscientific and anecdotal and there is plenty of reasoned argument from people with strong engineering backgrounds, like our fellow poster simsgw, who support Porsche's recommendations, or some version of them.

After going through these arguments multiple times some of us are loathe to wade through them again in another thread with no end, hence the horse beating idiom. Enough said, by me at least.

My turn to apologize, Gary.....

ScorpionT

Yes, some people dont want to follow the manual and would prefer to drive their cars out of the box. Some do and just enjoy it, while others want to find others who have technical explanations for doing the same. I have a step in the first group, but I continue to run engines in fairly hard because personal experience shows me it works and following the break in procedures isnt really necessary.

If you are referring to me as the "mate of a mate" you arent seeing the entire picture. The engine builders I trust all have 10+ years working with race engines, and average 1-2 engines per week, top to bottom assembly. No Porsche engineer has time to design parts as well as hand assemble that many engines in the same time frame, no doubt about it. When it comes to physically machining and assembling an engine I put my faith in guys who have built 1500+hp engines for race teams, I dont leave it up to an engineer who designs parts (yes, engineers design individual parts and small systems, not 1 engineer designing and engine from the bottom up).

Rather than blaming this on conspiracy theories, why dont you offer up some evidence and experience to back up your thoughts. "Porsche knows best" isnt much to stand on in a technical arena.

Thats why I give solid information on my experiences. I dont care what others do, Im just saying what I have done and what works and what doesnt. If someone drives like a grandmother for 5000 miles it makes no difference to me. I offer technical advice, take it or leave it.

I always drive more aggressively than that, but you arent babying it very much which can account for the noticeable power you have compared with most others. Proof is in the pudding.

rpilot

Groaaaaaaan.... oh wait, there is nothing on TV tonight.

greenpdk

When do you do your first oil change?

John 996 TT Cab

I have always done my first change relatively early. Normally at about 1/3 of the recommended time. For the 991 I will change the oil around 2500-3000 miles at most. I don't put a lot of miles on (my commute is 1 mile each way). I do have a trip planned in mid May and as long as I'm over the 2000 break in distance I will change the oil before that trip.

John 996 TT Cab

I change the oil in my 996TT once a year even though I only drive it about 3000 miles per year. On an ongoing basis I would expect to change oil on the 991S at least every 6000 miles at max notwithstanding Porsche says longer.

DrJay

I plan on doing a nice smoky 4 wheel drift at redline straight off the dealers lot when I get my 4S. Will that be good for the engine?











;-)

simsgw

Best possible attitude is reaching for the corn. I never argue politics, religion, or break-in policy because people invest their self-worth in their views and really don't want "an answer" because they already chose one. I've been listening to emotional debates on all three for nearly seven decades now.

What puzzles me is how "engine break-in" ever got shuffled into the deck with those other two. Fascinating. And the content hasn't changed since they were discussing the '57 Ford!

Gary

jmct

SB - I am thinking about this same topic for my March C4S Cab delivery, so I decided to read several of the threads on this, and looked at both extremes of the arguments (follow the manual vs. conspiracy theory). Below are two excerpts that made the most sense to me and that I will generally follow/consider. My firsthand engine experience is that I assembled a Ford V8 from the engine-block onward and did a lot of work on my '68 911 including replacing the clutch, so I'm familiar with the various terms and have a good sense for the issues:

1.
Last year I had the pleasure of meeting Andreas Preuninger, head of GT car development at Porsche. This was at the 997 RS 4.0 litre preview in the UK.
A few of us asked about running in. He said the following:
- For the first couple of hundred miles drive the car gently; no high revs and don't let the engine labour. The main thing here is bedding in tyres and brakes.
- Up to around 500 miles, vary engine load and speed. Use perhaps 2/3rd of the rev range (when warm of course). No full throttle.
- Between 500 and 1,000 miles start to use more of the revs, and larger (occasional full) throttle openings. (I tend to up my rev limit 1,000 rpm per 100 miles.)
- Beyond 1,000 miles drive the car as you wish.
He confirmed that most GT engines develop their full potential around 10,000 miles - most 3.8 RS engines were over 460hp (10 up on OEM figures) at this mileage.
I've pretty much used AP's technique for years now - most notably on a 996 GT3 Gen 2 that has now done 60,000 miles, half on track. The engine uses no oil, and still develops 430 hp (it has a Manthey map and exhaust).

2.
When we do our engine test, the metals inside the engine never reach the temperatures they would when driven on the street since the test session is fairly short. In other words, the bearings, pistons and cylinders never get a chance to thermally expand to their maximum. Therefore, there is little wear on the moving components. But when you drive a car on the street, the engine parts expand considerably more because of the heat being generated from the engine running for an extended period of time. No matter how tight the tolerances are, there is always a slight amount of expansion in the material. The moving parts can wear quickly if exposed to excessive heat and not always in a uniform way. We also constantly vary the speed and allow the engine to run at both high and low RPM’s”.
“Porsche wants the engine to break-in slowly, which means it needs to maintain a lower operating temperature (below 4,000 RPM) and to allow all parts to adjust (wear-in) within their own thermal expansion parameters. This is also the reason why Porsche wants the owner to vary the RPM throughout the break-in period; therefore the engine doesn’t get use to one operating temperature range”.
“Porsche has been using Mobil 1 Oil since the early 90’s. With its superior lubricating properties, it takes many miles of driving (without getting the engine too hot) before the components actually seat (or break-in). Porsche’s own tests reveal that after 2,000 miles have been driven, all of the moving parts have had a chance to wear into their adjacent surfaces and then an increase in engine RPM is permissible.”

simsgw

Because I get paid for my knowledge that I worked hard to acquire. I don't waste time arguing with people who already chose an answer based on their buddies. It's that simple.

People have asked politely in the past and I've answered at length. But I don't argue without a fee changing hands.

Gary

ScorpionT

You said nothing about conspiracy theories, nor use the argument "Porsche knows best".

My argument is based on personal experience, and I am always open to new ideas rather than being afraid of change. I want to learn new things everyday, and that why I said if someone can offer technical information as a basis for their argument, I am happy to listen.