New Car Break-In Recommendations: Manufacturer vs "Engine Builder"

Summary

In this video, the host discusses the break-in process for new cars and engines, highlighting two main schools of thought: following manufacturer guidelines to avoid high RPMs and heavy loads, or the 'engine builder' approach, which advocates for high RPMs and heavy loads to seat piston rings properly. The host leans towards the manufacturer's recommendations, citing most new car owners' normal driving habits and the adequacy of cylinder pressures at moderate RPMs. Personal break-in practices include avoiding idling, short trips, and lugging the engine, as well as varying engine speeds and loads to promote proper bearing wear and piston ring seating.

Takeaways

• 🚗 The video discusses the break-in process for new cars and engines, highlighting two main schools of thought.
• ⚙️ Manufacturers generally advise against 'racing the engine' and exceeding certain RPM limits during the first thousand miles to avoid excessive wear on engine components.
• 🛠️ The 'engine builder' perspective suggests that high RPMs and heavy loads are necessary to properly seat piston rings against cylinder walls.
• 🔧 The presenter leans towards the manufacturer's recommendations, arguing that most new cars are not pushed to extremes and still perform well.
• 💡 It's suggested that cylinder pressures can be high enough for proper break-in without extreme driving, as evidenced by the presenter's Subaru WRX experience.
• 🚫 The presenter avoids idling and short trips to ensure the engine reaches 'closed loop' operation, which is more efficient and beneficial for break-in.
• ♻️ The idea of using conventional oils for break-in due to higher friction is being challenged, as most new cars come with synthetic oils.
• 🛑 The presenter avoids using cruise control during break-in to vary engine speed and load, promoting a more natural break-in process.
• 🏞️ Engine braking is encouraged by the presenter as a way to help piston rings seat without exceeding RPM limits.
• 🚫 'Lugging' the engine, or running it at low RPMs under load, is discouraged as it can be detrimental to the break-in process.

Q & A

What are the two main schools of thought regarding engine break-in mentioned in the script?

The two main schools of thought regarding engine break-in are the manufacturer's recommendations and the engine builder's mindset.

What does the manufacturer typically recommend for new car or engine break-in?

Manufacturers typically recommend avoiding racing the engine, putting the engine under full load, and exceeding an arbitrary RPM limit for the first thousand miles or so.

What is the reasoning behind the manufacturer's break-in recommendations?

The reasoning is to avoid excessive wear on the bearing surfaces and gears, as new parts might have sharp edges and not fit together well initially.

What does the engine builder's mindset advocate for engine break-in?

The engine builder's mindset advocates racing the engine and putting it under heavy load to allow piston rings to seat properly against the cylinder walls.

What is the speaker's personal opinion on new car and engine break-in?

The speaker leans more towards the manufacturer's school of thought, believing that cylinder pressures can get high enough without racing the engine.

What specific practices does the speaker recommend when breaking in a new car or engine?

The speaker recommends avoiding idling, not taking short trips, allowing the engine revs to hang out high without exceeding RPM limits, and not using cruise control.

Why does the speaker avoid idling when breaking in a new car or engine?

Avoiding idling reduces the load on the engine, prevents the engine from running in a rich state for a long time, and allows the oil to reach its operating temperature.

What is 'closed loop' in the context of engine operation, and why is it important during break-in?

Closed loop is when fuel-injected engines operate at their designed stoichiometric ratio once they reach operating temperature. It's important during break-in to ensure proper fuel mixture and oil coating on cylinder walls.

Why does the speaker avoid lugging the engine during break-in?

Lugging the engine, or having the RPM too low under load, can cause strain and is not beneficial for the piston rings or bearing surfaces during the break-in period.

What is the speaker's view on using synthetic oils for engine break-in?

The speaker suggests that the notion that conventional oils are better for break-in is becoming outdated, as most new cars come with synthetic oil and there's no widespread evidence of synthetic oil being detrimental to the break-in process.

What is the speaker's approach to varying engine load and RPM during break-in?

The speaker varies the engine load and RPM by not using cruise control, changing gears, and allowing engine braking to ensure the engine experiences different harmonics and loads.

Outlines

00:00

🚗 New Car and Engine Break-In Basics

The paragraph discusses the two main schools of thought on engine and new car break-in. The first approach, recommended by manufacturers, advises against racing the engine or exceeding a certain RPM limit for the first thousand miles to prevent excessive wear on bearing surfaces and gears. The second approach, often associated with engine builders, suggests that heavy loads and high RPMs are necessary to properly seat piston rings against cylinder walls. The narrator leans towards the manufacturer's advice, citing that most new cars are not pushed to the limits and still perform well, implying that the break-in process recommended by manufacturers is sufficient.

05:01

🛠️ Personal Break-In Practices and Myths

In this paragraph, the narrator shares personal break-in practices, emphasizing avoiding idling, taking short trips, and maintaining a closed-loop fuel system for optimal operation. They also discuss the importance of allowing the engine oil to reach its operating temperature and varying engine RPMs to prevent prolonged exposure to specific harmonics. The paragraph debunks the myth that conventional oils are better for break-in than synthetic oils, suggesting that the widespread use of synthetic oils in new cars indicates their suitability for the break-in process. The narrator invites discussion on differing opinions and is open to new ideas on the subject.

10:03

📚 Engine Break-In Lore and Modern Practices

The final paragraph touches on the lore that conventional oils were once believed to be better for engine break-in due to higher friction, which was thought to benefit piston rings and bearing surfaces. However, this belief is being challenged as synthetic oils are now standard in new cars, suggesting that they are also effective for break-in. The narrator acknowledges the ongoing debate and the variety of opinions on engine break-in, indicating that there is no definitive scientific consensus. They express a willingness to share any issues that may arise with their new car as a result of following the manufacturer's break-in recommendations, emphasizing a commitment to providing accurate information.

Keywords

💡Engine Break-in

Engine break-in refers to the process of gradually and carefully using a new engine to allow its components to wear in and seat properly. In the video, the speaker discusses the two main schools of thought regarding engine break-in, emphasizing the importance of following certain practices during the initial phase of engine life to ensure longevity and optimal performance. The script mentions avoiding high RPMs and heavy loads during this period to prevent excessive wear on new engine parts.

💡RPM (Revolutions Per Minute)

RPM is a measure of the number of rotations in one minute made by an engine's crankshaft. It is a critical parameter in engine operation, with the video highlighting the manufacturer's recommendation to avoid exceeding a certain RPM limit during the break-in period of a new engine. For instance, the Subaru WRX mentioned in the script advises not to exceed 4000 RPM for the first thousand miles.

💡Piston Rings

Piston rings are circular components that fit into grooves around a piston. They are crucial for sealing the combustion chamber and controlling oil consumption. The video discusses the importance of seating these rings properly against the cylinder walls during the break-in period to prevent excessive oil burning or blow-by. The script contrasts the manufacturer's approach with the 'engine builder' mindset, which advocates for higher RPMs and loads to achieve this seating.

💡Boost

Boost refers to the increased pressure inside an engine's combustion chamber, which results from forced induction, typically via a turbocharger or supercharger. The video mentions that even when keeping RPMs within the recommended limits, the speaker's Subaru WRX can reach high levels of boost, indicating that cylinder pressures can be sufficiently high for proper engine operation and piston ring seating without redlining the engine.

💡Closed Loop

Closed loop is a term used to describe the state of a fuel-injected engine when it operates at its designed temperature and uses feedback from oxygen sensors to adjust the air-fuel mixture. The video explains that reaching closed-loop operation is important during the break-in period to ensure the engine runs at its optimal air-fuel ratio, which is crucial for proper piston ring seating and overall engine health.

💡Fuel Dilution

Fuel dilution occurs when excess fuel mixes with the engine oil, which can lead to reduced lubrication and potential engine damage. The video script mentions avoiding short trips to prevent the engine from running in a rich state for extended periods, which can cause fuel dilution and inhibit the proper seating of piston rings.

💡Engine Braking

Engine braking is the use of an engine to slow down a vehicle by disengaging the transmission and allowing the engine's compression to resist motion. The video suggests allowing the engine to brake when decelerating as a beneficial practice during the break-in period, which can help with piston ring seating without exceeding the manufacturer's RPM limits.

💡Lugging

Lugging an engine refers to operating it at a low RPM while under load, which can cause excessive stress and potentially damage the engine. The video advises against lugging, especially during the break-in period, recommending downshifting to keep the RPMs higher when accelerating or going uphill to prevent undue stress on the engine.

💡Cruise Control

Cruise control is a system that automatically maintains a vehicle's speed without the need for the driver to keep their foot on the accelerator. The video script mentions avoiding the use of cruise control during the break-in period to prevent the engine from running at a constant speed and RPM, which could inhibit the proper break-in of engine components.

💡Synthetic Oil

Synthetic oil is a type of engine oil that is chemically engineered rather than being derived from crude oil. The video discusses a shift away from the belief that conventional oils are better for break-in due to higher friction. The script points out that most new cars come with synthetic oil, suggesting that if synthetic oil were detrimental to break-in, manufacturers would likely recommend changing it after the first thousand miles.

Highlights

Discussing new car and engine break-in, with an emphasis on overlapping aspects.

Manufacturers recommend avoiding high RPM and full load during the first thousand miles to prevent excessive wear on engine components.

Specific manufacturer advice: Subaru WRX advises not exceeding 4000 RPM during the initial break-in period.

For vehicles used for towing, manufacturers also advise against towing during the first thousand miles.

The rationale behind manufacturer recommendations is to allow new engine parts to wear together gently.

Engine builder philosophy suggests high RPM and heavy load to seat piston rings properly against cylinder walls.

The presenter leans towards the manufacturer's break-in approach, citing the majority of new car owners' driving habits.

Avoiding idling is recommended to prevent fuel dilution and ensure proper piston ring fitment.

The importance of reaching closed-loop operation for proper engine function and piston ring seating.

Engine braking is encouraged to aid in piston ring seating without exceeding RPM limits.

Avoiding lugging the engine by downshifting to maintain appropriate RPM under load.

Cruise control should not be used during the break-in period to vary engine speed and load.

Varying engine harmonics is beneficial for bearing wear during the break-in period.

The presenter shares personal break-in practices, including avoiding synthetic oils for traditional break-in methods.

Modern cars often come with synthetic oil, indicating a shift in break-in oil preferences.

The presenter expresses openness to differing opinions and invites discussion on engine break-in practices.

Acknowledgment that the science of engine break-in may never be fully settled due to varying opinions and practices.

Transcripts

hey guys today i'm talking about new car

break-in

as well as engine braking so these two

topics they're

overlapping and as i'm doing this i'm

driving my 2021

subaru wrx and i'm first going to go

over the two

main schools of thought regarding engine

break-in

and new car break-in and i'm going to

tell you the reasoning behind them

and later on i'll give you my own

personal thoughts on the best way to

break in

a new car and or a new engine so

starting with what the manufacturers say

so uh

the specific variations um

are not so important but all

manufacturers pretty much

say that while the car is new or the

engine is new you want to avoid

quote unquote racing the engine you want

to avoid putting the engine under a full

load

and you'll also want to avoid

exceeding an arbitrary rpm limit for the

first

thousand miles or so specifically on the

subaru wrx

as you can see this one it's got a

hundred and eighty thousand miles so i'm

doing the break in now

subaru says to not exceed 4000 rpm

during the first thousand miles unless

in cases of emergency

uh now manufacturers of trucks or other

vehicles that do

towing they will also tell you in

addition to not exceeding a certain rpm

they will tell you to not uh

tow anything for the first thousand

miles or so

and even beyond that when you first

toast something they will tell you to

pull over after the first 10 or 15

minutes

and allow for the differential to cool

down

now the reason why all these

manufacturers have the same

general recommendations the idea behind

that is to avoid

uh excessive wear on the bearing

surfaces

and the uh basically the surfaces on the

bearings that

uh rub up against one another

and it also helps with the gears so the

differential all the gears that mesh

together

as well as in the transmission now the

idea is that

the bearings and the gears being so new

they might have sharp edges

and they might not fit together as well

when they're brand new so you want to

avoid

putting a lot of power through them

until the surfaces have worn together

so that's the general philosophy behind

the manufacturer recommendations

regarding break-in now another popular

school of thought regarding engine

break-in

is what i can call the engine builder

mindset and generally speaking this

mindset is that

you have to race the engine you have to

put the engine under a heavy load

for a prolonged period of time you want

to keep the rpms high

and the school of thought behind this is

that

only by doing these things can you

increase the cylinder

pressures high enough to allow for the

piston rings to seat properly against

the cylinder walls

and proponents of the what i call the

engine breaker school of thought

they'll tell you that unless you do

those things on your new engine or your

new car

you'll end up with an engine that is

burning excessive oil

or has excessive blow by due to the

piston rings not seating properly

uh so those are the two main schools of

thought now i'm gonna give

my input on uh what i think about new

car and new engine breaking in

and i'm gonna try to keep it brief

because i can go on and on about the

subject pretty much all day

but i'll tell you that i lean more

towards the manufacturer school of

thought

and i'll tell you why for one

if the engine breaker if the engine

builders if their

methodology was correct then we would

see

a lot more cars on the road that are

burning oil

because i can tell you right now most

people that buy new cars

they're not running them balls to the

wall they're not

uh hitting the rev limiter they're not

putting them under a heavy load

um and as it stands you know most people

are buying new cars and they're just

driving them normally

uh so i think there is something to the

manufacturer recommendations

you know i think cylinder pressures get

high enough

without racing the engine or putting it

under a full load

you know even at 4000 rpm you can see

my car has reached over nine pounds of

boost

from me driving it in this manner so

even with me keeping the rpms down

i'm still hitting a lot of boost and my

cylinder pressures they're going to be

high you know they might not be as high

as if i was redlining the car

doing wide open throttle up a hill uh

but you know

i'm confident that my piston rings are

not going to have any issues that they

wouldn't otherwise have

things that i do specifically when i'm

breaking in a car or a motor

i avoid idling so once i get the vehicle

running

i'm driving it i'm not letting it idle

i'm not letting it warm up

i'm avoiding sitting at a red light

and uh in the case that i do have to sit

at a red light for a long period of time

i'll turn off my air conditioning if i

have it on

this will reduce the load on the engine

while it's at idle

so that's one thing i do i also avoid

taking a lot of short trips

what i want to do is i want to start the

car start driving it i want the coolant

temperature to get up there

so that the motor reaches what's called

closed

loop so closed loop is something that

fuel injected engines

do once they're reaching their operating

temperature

so under closed loop that's when the

stoichiometric ratio

is um closer to the 14.7 that we all

learned in the textbook

during open loop when the engine is

warming up your engine is going to be

running

a bit richer and so if you keep doing

short trips

not allowing the engine to reach closed

loop then you're basically running the

engine

in a rich state for a long period of

time

this can lead to fuel dilution

an engine running rich it can also

inhibit the

oil coating on the cylinder walls which

will allow for the proper

piston ring fitment

so yeah i wanted to go into closed loop

and stay there

um running it for a longer period of

time will also allow the oil to reach

its operating temperature

and uh this is something that takes

longer than the coolant the coolant will

get to its operating temperature

much sooner than the oil will so yeah

run the engine uh run the car for a

while i don't do the short trips

and one thing that i have taken from the

engine builder philosophy

is without exceeding the rpm limit

i will allow the engine revs to hang out

high

i will allow the car to engine brake

whenever possible

so sometimes when i do wish to

decelerate i'll shift it into a higher

gear to allow that engine breaking

action to occur

and i believe that this is beneficial

for the piston rings

uh one other thing that i do and this is

something i do in general

whether i'm breaking in a motor or not

is i

avoid lugging the engine so lugging the

engine

is basically what you can call having

the rpm

of the motor too low while you're

putting a load on the engine

so if i need some power i'll downshift

i don't want my engine to be revving at

1800 rpm

when i'm trying to accelerate especially

if i'm going up a hill

so i try to keep the rpms higher another

thing i do

when driving when braking in a new car

or a new

engine is i will not use the cruise

control

so i want the speed of the engine to

constantly vary

provided i don't exceed the manufacturer

recommended

rpm limit

so i don't allow the car to just

you know be sitting in fifth gear at you

know

2800 rpm for minutes and minutes so i

want to always be switching to different

gears

i'm varying the load i'm varying the rpm

and i the idea behind this is

you want to vary the harmonics of the

engine

when the engine is uh you know when the

engine is spinning at a certain rpm

there's a harmonic associated with that

and if you allow the engine to hang out

at the same rpm and the same load

for a long period of time the theory is

you're hanging out in that specific

harmonic for too long

and you're inhibiting the proper bearing

wherein

so as you may have guessed there's a lot

of

juju to this this is a topic that people

have been arguing about

pretty much as long as engines have been

around and

uh i suspect that the science will never

be settled

pretty much anyone you speak to will

have a different opinion on

engine break-in and it's a bit like it's

a bit like

oil everyone has different thoughts on

what kind of oils to use

but i just thought i'd share my thoughts

on the new car and the new engine

break-in

and i'm interested to hear about what

you guys have to say

what your thoughts are regarding new

engines new cars

how they should be properly broken in

one thing i will share with you as well

for a long period of time

there was sort of i'll call it lore

so the lore was that conventional oils

were better for break-in as compared to

synthetic oils

because the conventional oils allow for

more friction

which can be beneficial for the uh

piston rings and the bearing surfaces so

that used to be the

that used to be lore people are kind of

moving away from that now

pretty much any new car you buy is going

to come out of the box with

fully synthetic fluid and so if

full synthetic fluid was so detrimental

for the break-in process

i'm pretty sure manufacturers would be

shipping their cars with conventional

oil

with the advice to change that oil after

the first thousand miles or so

there are many other myths regarding

engine break-in

don't really have time to go over all of

the ones that i've heard but

i'd like to hear about it in the

discussions below

so yeah i appreciate you guys watching i

want to hear about

any differing opinions that you guys

have always open to new ideas

and of course you know with this car i'm

driving right now being new

if it develops a problem burning oil

after i've done the manufacturer

recommended break-in

i'll definitely share that with you guys

you know i want to

put good information out there that's

accurate so yeah

thanks for watching