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.