[HDRDTD]

Originally Posted by MrChrisLS3

Keep in mind that it's more than just the engine you're breaking in. It's the entire drive line, the transmission, the differential, drive axles, all of it. A lot of moving parts with gears.

When the 5th Gen ZL1 came out, the official break-in period was 1,500 miles. Much longer than the expected 500 mile. We couldn't get an answer from anyone including GM why the period was increased to 1,500 miles.

The one thing that came to my mind that might explain the long period was the horsepower. Remember this was back in 2011 when buying a new car with 580hp was a big deal. I believe the ZL1 was the first to come with a selection of PTM modes, of witch PTM 5 was meant to be used when on a 'well-prepped' drag strip.

It also came with Traction Control, Stability Control, etc, etc. Quite the muscle car at that time. Of course many new owners would immediately turn off on the nannies, end up wrapping it around a tree.

My guess is the long break-in period was needed for the mechanicals whether the transmission, the rear end, the engine, etc,

To me it was to let the new owner operate the car at a more sedate level until they could get a sense of the power/potential of the car before letting them stretch it's legs finally at 1,500 miles.

But again that's just my own opinion.

[s346k]

Originally Posted by Petrol Head

As the owner of a 2009 Honda Accord EX-L V6 6 speed coupe since it had 2 miles on the odometer (~175,000 now), which has essentially the same engine in his TL, I’ll just say this:

I was easy on the car for that 500 miles, but Honda’s owners manual also states to leave the factory oil in as long as possible. The engine parts are coated at the factory and they want it in the engine as long as possible. So I waited till I was at absolute zero on my oil life indicator, approx 7500 miles, to do my first oil change.

Today I can drive it hard, shift through the gears at redline, and it doesn’t burn or leak a drop of oil while still putting out every one of the factory 260 hp. Might have even gained a pony or two over the years - the engine is strong as ever. All the while giving me 24 mpg.

Just sayin.

this is a poor example. the 23 yo/300k mile engine in my jeep can have the same said about it. power, fuel economy, oil use etc. it was a state owned vehicle, which means you know they didn't follow any kind of break in upon purchase and furthermore they let prisoners maintain it from 1997-2011. the break in has no bearing on longevity and general performance. all of that is covered in the assembly of the engine itself.

[ScatPack]

Modern "break-in" periods are mainly for driveline parts. Engines really just need an initial oil change after a few hundred miles to get out any metal shavings that might has been caught in the oil filter. But I personally always break in my new cars the way I drive them. HARD. 0 miles or 1500 miles, I will drive a car to redline and beat on it. Never had a problem and I have bought a new car every two years or so over the last 15 years. Granted my cars never get past 15k miles or so, so who knows what the extended life of the engines will be.

[Petrol Head]

Originally Posted by s346k

this is a poor example. the 23 yo/300k mile engine in my jeep can have the same said about it. power, fuel economy, oil use etc. it was a state owned vehicle, which means you know they didn't follow any kind of break in upon purchase and furthermore they let prisoners maintain it from 1997-2011. the break in has no bearing on longevity and general performance. all of that is covered in the assembly of the engine itself.

You also have a motor that dates back to WWII. Simple design and proven reliability over 70+ years.

[wwiiavfan]

This is a debate as old as the hills. I’ve always had good luck with breaking them in like you are going to drive it. If you’re gonna baby it, give it a nice long gentle break in. Otherwise just drive it like ya stole it.

[ember1205]

Originally Posted by UnknownJinX

Meanwhile, the Track Preparation Manual says to change the oil at 500 miles. I did, as I was actually seeing some tiny metal speckles on the dipstick.

I don't think GM uses special break-in oil as Honda does.

Yeah, that's what kind of threw me... Same motor, but different break-in process. And only "if" you are going to track it should you add the extra oil change.

Not only have I never heard of GM using any special additives in the oil in any of their cars, that's what what kind of "sold me" on the premise that there weren't any in this engine. I opted to do the early oil change because I wanted to visibly inspect the clarity of the oil right out of the gate. I was surprised at how dark the oil was after 600 miles, but it did not appear to be carrying any contaminants. Even after the drain pan sat overnight, there wasn't anything left sitting on the top after the oil had drained away.

[s346k]

Originally Posted by Petrol Head

You also have a motor that dates back to WWII. Simple design and proven reliability over 70+ years.

an engine is an engine. if anything, the materials used in the jeep engine are far inferior to those used in modern stuff. hell, it has a flat tappet camshaft and unbalanced rotating assembly, a terrible cylinder head design prone to cracking combined with a very inadequate cooling system.

point being: it doesn't matter. sh'ts gonna break in or break.

[JamesNoBrakes]

Originally Posted by ScatPack

Never had a problem and I have bought a new car every two years or so over the last 15 years. Granted my cars never get past 15k miles or so, so who knows what the extended life of the engines will be.

Well yeah...then it becomes someone else's problem...

[Allez]

What the heck do those engineers who designed the engine know? Much better to listen to people on the internet!

[caSStro18]

Originally Posted by Allez

What the heck do those engineers who designed the engine know? Much better to listen to people on the internet!

That’s the part I don’t get. Why tell people there’s a break in period if it’s really not needed? I guess ultimately people do whatever they want with the cars they spend their money on. I guess maybe they’re (The engineers) just playing it safe. Which is what I do. Also, the new C8 won’t even allow you to drive it hard until the break in period is over. So there must be something to the whole break in thing. But, I’m not an engineer so what do I know?

[ember1205]

Break in periods are generally used to allow very small imperfections from manufacturing to "wear in" before you run the mechanical pieces at full tilt. A small particle in the groove of a piston could prevent a ring from being able to fully retract, and that could score a cylinder wall. By running things more conservatively, it can allow that imperfection to wear down so that the ring seats correctly and never causes an issue.

Manufacturing processes are better than they have ever been. Still, there exists the chance of a small imperfection that lighter use can mitigate.

Not following the procedure generally will not void your warranty, but there's no reason that we can't all play it safe and follow the procedure.

[arpad_m]

Originally Posted by samurai

On the C8 Corvette the maximum torque of the car is recuded and digital redline lower is set lower in the gauges for the first 500 miles. I trust the engineers of the cars who recommend a break in period more than some know it all on the internet.

The larger the company, the less say engineers have in what info gets published and the more it's up to the legal department. People want the truth and if they can't trust official sources any longer, they will turn elsewhere, always have, always will.

[s346k]

it takes far more than 500 miles to "break in" an engine. closer to 10k miles before it is 100%. evidenced by those who closely track performance, oil consumption etc. as mileage goes up, so does power and inversely oil use goes down. take big trucks for example, it takes 80k miles before they are "broken in". those engines don't have a restricted use parameter despite making 2k ft lb of tq and very high temperatures.

and since when did anyone trust an engineer? lol

[caSStro18]

Originally Posted by s346k

and since when did anyone trust an engineer? lol

I do! If you drive a car at all you probably trust them at least a little. Otherwise you'd always be afraid the car was going to fall apart or break down.