Running in a new car

[charged]

Dont know if this is true but ive been told that if you run a new car in hard,the ecu programs itself for more performance

[TheOne]

you first gotta let the car break for the first 500-1000 to sometimes 2000 miles.......before running it hard.
the ecu aparently gives a bit more performance after so many miles.

[my porsche]

no, the engine and ecu wears in however you drive it for the first 500-1000 miles, so if you drive very fast, then the car will feel more comfortable to drive at those speeds, versus slower speeds

[my porsche]

but yeah, running it hard right outta the box, so to speak is bad, give it a few miles, a few hundred to get broken in, but dont drive too slow if you want it broken in at a higher rpm running rate

[my porsche]

my bad, i assumed we were talking about high performance engines, with different charecteristics, but johnny numfive was talkin to me and he said everyday cars, so scratch what i siad

[Sweeney921]

alright, why'd you make 3 posts to say those things
use the EDIT button!

[my porsche]

im terribly sorry sweeney

[Matra et Alpine]

Running in is important regardless of the intended revs and speed of the future use of the car. HOWEVER, where you may be getting a crossed line about is that it is EQUALLY BAD to run a new engine at too low revs. Engine tuners always provide a power BAND for engine load.

Running in lets the surfaces harden and small imperfections wear without excessive damage.

AFTER that ( and the time/duration ) depends on the manufacturer and components you can drive the car either gently or hard.

Some ECUs have built-in rev limiters and in VVT even torque limiters for the first miles. But it's not dependant on how you drive it. ECUs also constanly monitor and reprogram their maps based on the measurements it makes on the environment and the engine. Never heard of an ECU deciding how to let an owner drive a car based on it's run-in tho' Cant' see any reason why - is it maybe jstu that the ECU won't let the new performacne be available until it's done the appropriate run-in ? Like described above ??

[taz_rocks_miami]

What's a reasonable break in period Matra? What RPMs should we limit our shifting to till' the engine is broken in? I know it differs from car to car but are there any general "rules" we should follow?

[Matra et Alpine]

Originally Posted by taz_rocks_miami

What's a reasonable break in period Matra? What RPMs should we limit our shifting to till' the engine is broken in? I know it differs from car to car but are there any general "rules" we should follow?

I really depends on the materials the engine and components are made from.
The types of bearings, expected oil film thickness and pressures.
Types of rings and liners, numebr of rings.
The tolerances.
Traditionally a blue-printed engine with a square ring and one scraper in a steel block and high-lift cam, double springs would be 100-300 miles at 1/2 max revs, 300-500 miles at 2/3 max revs then let rip. The engine is then good for 5000 competition miles or 50000+ 'tame' miles.

Modern materials change all that. One example is Kawasaki ZX-12 engine. Was one of the most powerful and originally was 1500 miles run in and then went to 5000 miles after they foudn the cams didn't form a hardened coating till late on in the wear curve. So they had to recommend extending the run-in to get the lobes to harden up and not wear so quickly later.

So, always important to listen to manufacture and tuner on what they've built

[taz_rocks_miami]

Originally Posted by Matra et Alpine

I really depends on the materials the engine and components are made from.
The types of bearings, expected oil film thickness and pressures.
Types of rings and liners, numebr of rings.
The tolerances.
Traditionally a blue-printed engine with a square ring and one scraper in a steel block and high-lift cam, double springs would be 100-300 miles at 1/2 max revs, 300-500 miles at 2/3 max revs then let rip. The engine is then good for 5000 competition miles or 50000+ 'tame' miles.

Ok, I've driven my new cars at 1/2 revs for about 200 to 300 miles like you've said. After that I always get impatient and let her rip like you said. I've never had to tear an engine (street car) down. Guess I'm lucky.

Originally Posted by Matra et Alpine

Modern materials change all that. One example is Kawasaki ZX-12 engine. Was one of the most powerful and originally was 1500 miles run in and then went to 5000 miles after they foudn the cams didn't form a hardened coating till late on in the wear curve. So they had to recommend extending the run-in to get the lobes to harden up and not wear so quickly later.

So, always important to listen to manufacture and tuner on what they've built

Thanks Matra, I'll take your answer into account with my next car. Cheers!

[Matra et Alpine]

Originally Posted by taz_rocks_miami

Thanks Matra, I'll take your answer into account with my next car. Cheers!

You don't need to be so careful with many modern cars.
The materials and especially the rings used mean better wear rates.
Often the surfaces are treated rather than relying on 'run-in'.
Follow the manufacturers recommendation.

[jcp123]

I've always done break in like this:

Take it real easy for the first 250 miles, then after that, you can frankly rev it as hard as you want, as long as you dont do sustained revs over 4000. Change the oil at 500 miles, and again at 1000. Also, for that first 1000 miles, take care to vary your speeds, never letting the car steele into a particular speed for more than 5 minutes at a time.

[Matra et Alpine]

Originally Posted by jcp123

Change the oil at 500 miles, and again at 1000. Also, for that first 1000 miles, take care to vary your speeds, never letting the car steele into a particular speed for more than 5 minutes at a time.

Yeah, good points, jcp, I should have added that an oil change VERY early is a good idea on comp engines as you can inspect it in case any bearings are shedding badly.
Also the point on settling in to revs I missed passing on too.
Bad weekend
The engineering pricniple behind that one is that sitting at steady revs MAY be close to a harmonic for any one component so THAT component may be more stressed or receive more stress or wear. It then may be more likely NOT to have 'run in' nicely.
Good addition to the list jcp.

[crisis]

When I got my Commodore , a couple of years back now, the saleman said get in and drive normally. I wonder what he thought was normal driving for a 350 V8 six speed? Anyhow I took it fairly easy but varied the speed, easy enough in city driving. I remember when you used to see cars with signs in the back window "running in" they had to be treated with kid gloves.