Best way to break in a new engine?

[Burstofspeed]

What is everyone doing/done to break in their new engines? I've read various opinions from taking it easy to drive it like you stole it. Also should I put some miles on it first before I start engine modding? Just got my 35D and thinking of adding a Race Chip.

[cenix]

you're going to get a lot of differing opinions here or anywhere else. your owner's manual states clearly how you should break in the car and it does not indicate that you should be driving hard and racing the motor.

[Blackhawks]

I never went above 3,500rpm for the first 1,200mi. Some think I'm crazy but I've never had major issues with any car I've ever owned... So I stick to the plan that I fee has always worked for me.

[X5Jouster]

never actually had documented engine issues, only oil eating, and loud noises.

2010 MBenz GLK350 V6 40,000 MI

2010 BMW 335i(Cobb Tune)20,000 MI

2012 3.6 V6 Jeep Wrangler(Diablo Tune) 40,000 MI

2013 Audi S6(which i would buy again and tune for 600HP/TQ) 12,000 MI (Totaled)

2014 BMW x5 50i (BMS tune) 13,000 MI SO FAR!!!!

2010 Yamaha Twin Engine Jet Boat (VW 1.8 ENGINES)

Motorcycles and ATVS Suzuki and Yamaha

i have ALWAYS DRIVEN LIKE I STOLE IT. like hard, i beat on my vehicles, and

i have never had serious engine troubles/rebuilds/failures. (knock on wood)

ive hit rev limiter on every vehicle before i had 1K miles..and probably way more then once


Remember to change your oil every 5,000 miles!

[ano0oj]

I typically break in any car for 1000mi and keep it under 3500-4000rpm.
Towards the end, where I'm close to 8-900 is when I'll start driving a little harder

[MotoWPK]

Originally Posted by X5Jouster

never actually had documented engine issues, only oil eating, and loud noises.
...
i have ALWAYS DRIVEN LIKE I STOLE IT. like hard, i beat on my vehicles, and

i have never had serious engine troubles/rebuilds/failures. (knock on wood)

ive hit rev limiter on every vehicle before i had 1K miles..and probably way more then once


Remember to change your oil every 5,000 miles!

I would consider "oil eating" and "loud noises" an issue and a possible prelude to "engine troubles/rebuilds/failures" that "ALWAYS DRIVEN LIKE I STOLE IT" contribute to.

[X5Jouster]

Originally Posted by MotoWPK

I would consider "oil eating" and "loud noises" an issue and a possible prelude to "engine troubles/rebuilds/failures" that "ALWAYS DRIVEN LIKE I STOLE IT" contribute to.

Audi and BMW V8 turbo engines are known for it!!!!! not terrible oil eating but 2 quarts in between each oil change....which isnt all that terrible considering how clean my oil comes out after first oil change. (Blackstone results)

loud noises being tappy engines, which might be oil related in hot Florida...


maybe to correct myself...never had one engine issue driving it like i stole it from mile 1 - 40,000 miles

[RR-NYC]

Follow the owners manual; its simple and written by the same people that designed and built it.

After I reach about 750, I push the engine a little harder, especially with kickdowns but only on rare occasion

[r33_RGSport]

I don't believe in break-in.
Factory broke it in already before delivery.
If the engine can stand the abuse from day one, then it will stand strong for a long time.

[Kzang]

No shit! Factory revs the crap out our brand spankin new engines with stress tests before it gets loaded on the transport truck to your dealer!

[kanvas]

Best way to break in? No bursts of speed, OP

[turboawd]

i think the worst thing to do to a new engine, is extended idling. otherwise just drive it normal. or hard. lol

[5tony]

I do a progressive break in. Couple of hundred miles below 4000 RPM. Then a couple hundred below 5000, etc. Within 800 miles, full RPM. Also, avoid extended idling and cruising at the same RPM.

[leo95se]

Originally Posted by 5tony

I do a progressive break in. Couple of hundred miles below 4000 RPM. Then a couple hundred below 5000, etc. Within 800 miles, full RPM. Also, avoid extended idling and cruising at the same RPM.

Exactly. And avoid long cruise control highway type drives where you keep rom constant.
The idea is to get rings to shape to the cylinder walls with varying load.

Don't forget other items like brakes too!

[Burstofspeed]

Originally Posted by kanvas

Best way to break in? No bursts of speed, OP

I bought mine off the lot, so it already had 40 miles of test drives on it including mine so I think it's already been pushed a little hard. I don't drive too crazy and spend most of my time in Eco. As of now I do mainly mixed city/ highway driving but I do have a couple longer trips coming up, good to know about cruising at constant RPM. I would think the auto start/stop would helps to eliminate prolonged idles.

[r33_RGSport]

Oh come on guys, the manufacturing technoogy is not in the stone age anymore.
The machining process and material quality etc are much2 better.
The reason you need a break in period 30-40 years ago is because you need to let the engine to smooth out the edges properly. That's why you need to change the oil for the first 1000 miles to get out those shaving and flashes that got grind off during break-in period.
Even 20 years ago, we don't even need to break-in anymore. All my friend's break-in engine's oil are clean, no grime or metal shaving in the oil.
But, for the 80's car, that was different story, even after 40k miles, you still see metal shaving or grimes in the oil.
Even an engine warm up, I don't do it for the same reason, plus the tecnology in new oils. Just don't punch it before the engine warmed up though.
The truth, when I drive a car that has been properly broken in, I felt the engine having a hard time to go fast. Doesn't feel as light and quick going across the RPM range.

[r33_RGSport]

Oh, to add, once e you start your engine, it idles at about 1000 rpm, which is 16.7revolution per second.
And when you drive normaly, it bring about 3000rpm / 50 cycle per second.
That is alot and fast already.
Do you think going even faster than 50 cycle per second will matter much?

[FamilyMan]

I've read about this topic since 2002 with my first BMW. I'm not an expert on this topic but there seems to be a couple thoughts I can't quite reconcile.

1. At the factory they do test the engine as others have stated. However, that occurs in a controlled environment and performed at discrete intervals. Does this then mean that the engine can be driven hard upon delivery? I'm not 100% convinced.

2. When reading mechanical experts on this topic who have kept their BMWs for over 200k miles there are some who believe that evidence exists to support a hard break-in along with Old School Maintenance keeps a BMW engine performing strong for hundreds of thousands of miles. Also, by driving it hard right out of the gates this makes the car perform faster (not sure why this would be the case).

As we all know this topic brings very strong opinions and we all are enthusiastic about our cars and want the best ownership experience, but it continues to be a topic without a clear answer (at least for me)

Following the owners manual would not harm your engine so that sounds like the least risky way to go.

Personally I land somewhere in between the two views.

I know things like brakes, tires, and engine components need time to settle in. But I enjoy spirited driving so I'll enjoy it say within 6,000 rpms from time to time.

I kept my 2 previous BMWs with about 75k miles and never had an engine or transmission issues.

Good luck and just make sure to enjoy the ride!

[Alan l.]

I vary my rpms during break in. I believe in the hard break in to some degree but I wouldn't go and beat the crap out of my car right off the showroom floor or even daily driving.

Obviously no hard driving until the engine is fully warm for at least 10mins.

Kept the RPM's below 4K for 95% of my driving with an occasional trip past that every now and then to ease it in so to speak. Key for me is to prevent hard transmission kick down during break in because you aren't just breaking in the motor for the first 1200 miles. All of the mechanical parts, seals are all going through the same thing.

What I've noticed with my past BMW's is that driving it hard usually makes everything feel smoother/better afterwards. The car idles smoother, the manual gearbox goes into gear more slick.

Alan

[MotoWPK]

Initial test runs at the factory are for very short periods of time, limiting the additional thermal loading that occurs due to localized contact points that exist until contact surfaces wear in. While manufacturing development over the years has reduced this, it still exists and is the reason manufacturers recommend moderate engine load during a break in period.

Another application that is some times referred to as evidence of the best way to break in an engine is racing, where engines are used at maximum output immediately. In racing there isn't time for a gradual break in and racing engines are required to last many tens of thousands or hundreds of thousands of miles.

You can always take the advice found by contributors to an internet forum, or the advice of the those who designed, developed, manufactured and warrant the engine, and whose reputation depends on those engines' reliability and longevity. Your choice.

[stewy604]

Just "drive it." In breaking in new cars, especially those that I had purchased (not leased), I've always done the following for at least the first 5,000 kms:

-avoided high rpms (tried to keep it below 3,500-4,000)
-for forced induction engines, avoided high boost levels
-avoided extended cruising at constant speed/rpm (road trips)

With all that said, I've had friends do none of the following, and literally bag on the car since day 1 without issues long term.

[Kzang]

Originally Posted by MotoWPK

You can always take the advice found by contributors to an internet forum, or the advice of the those who designed, developed, manufactured and warrant the engine, and whose reputation depends on those engines' reliability and longevity. Your choice.

Good advise!
What is interesting here is that the same argument is made about oil change intervals as well