[Traumamoma]

Greetings all. I know, I know. There are many threads discussing this issue, but I wanted to share the opinion of a very well respected GM tuner who has worked on many of my cars including camaros and corvettes. His opinion is that if you drive the car " hard" right out of the box it will make more power down the road. He recommends ignoring the GM break in recommendations and driving the car
"Like you stole it" right from the get go if you want it to make max HP down the road. This is not some guy at a car show shooting off his mouth, but a guy who travels to the Middle East twice a year to tune and teach tuning. I bring it up because I just bought a 2017 1SS1LE and am torn between following his advice or the GM recs. Just interested if anyone out there is not following the GM recs and going all in right from the start. Regards, Peter

[Eric SS]

Tuners will almost always say to run it hard from the start. Manufacturers will tell you to follow their instructions. Being that when I purchased my car it had 180 miles on it you can probably guess how mine was broken in before I ended up buying it.

The good news is I would have broken it in the same way I used to build engines (1st Gen Chevy Small Blocks mostly) and always broke them in hard.

[Abdulisraddd]

I just hit 1k miles on my car and it has not been babied not even once

[Racerman27410]

My father and i have built many engines together and he always said you only get one chance to seat the rings in a new engine and thats by getting the engine up to temp then running it hard up the revs and then let the engine compression brake.
three or four runs through the gears was all it took.... We never had a engine use any oil and the compression numbers were always good.

JMO but I honestly think nowadays every engine that comes out of the factory is run in on a dyno before installation in the car or after the car is assembled.... in which case the rings are where they are going to be and will not change regardless of whether you run it hard or take it easy.

I think the break in miles recommendation is more to give the driver time to get used to the car before stomping down on the go pedal and potentially getting into trouble.

[datboi448]

Some say that the transmission/diff need the time to break in more than the engine due to harder metals. Some say that the transmission/diff don't need a break in and just only wear down from the get go.

Sometimes I wish I hadn't changed majors from mechanical engineering to computers...

[MotownBoy]

Lord, does this manure have to come up on every site with cool, fast cars?

Barf.

Why would anyone in their right mind not follow what the car maker says?

[ron scubadiver]

1500 miles as recommended by GM seems like a lot. Beating the crap out of a new engine seems extreme. This argument will go on forever.

[Traumamoma]

I guess GM is looking at engine longevity and the tuners engine power

[Lukemo]

Originally Posted by Traumamoma

I guess GM is looking at engine longevity

Or it's a big conspiracy and their recommended break in period is actually a well conceived plot to destroy your engine faster so that you'll have to buy another one

[JeromeS13]

Originally Posted by MotownBoy

Lord, does this manure have to come up on every site with cool, fast cars?

Barf.

Why would anyone in their right mind not follow what the car maker says?

GM also recommends performing the first oil change at 7500 miles... Who does that?

[ST1LE]

Originally Posted by MotownBoy

Lord, does this manure have to come up on every site with cool, fast cars?

Barf.

Why would anyone in their right mind not follow what the car maker says?

Probably because people in their 'right mind' know the car maker is only concerned about themselves. Does GM care if your engine has well seated seals, burning less oil, and making more power after you have already given them your money?

This is exactly the sort of thing that comes up on forums, it is literally the point. Otherwise you would have NO clue the other side of the coin, only what a selfish car manufacturer 'tells you to do'. Do what you are told all you like, doesn't make it right. Willful ignorance is still ignorance.

[ST1LE]

Originally Posted by Racerman27410

My father and i have built many engines together and he always said you only get one chance to seat the rings in a new engine and thats by getting the engine up to temp then running it hard up the revs and then let the engine compression brake.
three or four runs through the gears was all it took.... We never had a engine use any oil and the compression numbers were always good.

JMO but I honestly think nowadays every engine that comes out of the factory is run in on a dyno before installation in the car or after the car is assembled.... in which case the rings are where they are going to be and will not change regardless of whether you run it hard or take it easy.

I think the break in miles recommendation is more to give the driver time to get used to the car before stomping down on the go pedal and potentially getting into trouble.

Thank you for your insight sir!! Helping forum members that want to know.

[FLYNNZL1]

check this out:
5 Things You Should Never Do In A Brand New Car

[ctrlz]

The break-in process is basically smoothing out irregularities in metal. If the surfaces involved were made of wood, would you rather try to clean them up with a few sharp swipes with a chisel, or work them with increasingly finer grits of sandpaper?
That's how I conceptualize this process.

And I agree with the tuner's advice regarding warm-up. No engine should be worked near its limits until it is at operating temperature.