Breaking in new 250- Myth vs Fact

[MoneyMan]

Buying LC 250-dealor is 1500 miles from where it will be garaged. Got to drive it back home. How does everybody break in their new LC?
1. Don’t use cruise first 500 miles at a constant speed?
2. Alternate acceleration during first 500 miles?
3. Drive it like you intend to drive it after it has 1 mile on odometer?

 

[westla4x4]

I think at this point the engine tolerances are tight enough to not need a full on "break-in". I just drove with a real light foot for the first 1k miles and did an oil change. Oil still looked brand new, but I'm neurotic. Prob would be fine to just drive 10k miles on that original oil which is what my dealer recommended.

 

[Jetboy]

The basic idea of how traditional engine wear in was done was to make sure that you had enough cylinder pressure to push the piston rings firmly against the cylinder walls to wear down the ridges, but not overheat anything and the function was to essentially finish machining the plateau in the cylinder wall and wear harden the ring surface.

In today's world there's very little if any of that needed in a new engine. The image below is a high resolution example of what a cylinder wall should look like. The top is the inside of the cylinder wall and has an obvious plateau where the rings of the piston will slide against to seal the combustion chamber. The deeper valleys shown are also critical to proper operation. Those are where oil will be deposited and retained to lubricate the cylinder walls. You do not want the cylinder walls to be polished. The engine would fail quickly with cylinder walls that are too smooth. Historically the profile below would have a lot more peaks above the plateau that the rings would need to knock down during the break in. That was called "seating the rings" which is a bit of a misnomer because you're really not seating the rings in the piston grooves like the name implies - you were wear machining/polishing the cylinder walls to set the plateau.

From what I've read about modern engine manufacturing - the only thing you really should avoid is long periods of idle during the first few hundred miles and ideally also avoid very short drives (like test drives?) because the short drives tend to over-fuel and fuel wash the cylinder walls that could result in excessive initial wear and a failure to crate that initial plateau. But - again, most current engines should be machined very close to the final desired wall texture profile before the first crank.

Hope that helps explain a little bit of the reason for breaking in and why it's not as important now as it was in the past.

I personally just follow exactly what the MFG tells me to. They have more information than I could ever hope to. I do usually change the oil before the recommended 10k change. Usually i would change at about 1,000 miles.

All of the other bearings and gears are also wearing in - the trans gears, differentials, etc. All of those I'd want to take it a bit easy on for the first few hundred miles to let them wear in a bit. Ring and pinions and trans gears in particular.

Good luck!

 

[ryanjl]

The science backs up the notion of doing an oil change at 1k miles or less.



Beyond that, I'm changing oil every 5k miles. With the turbo on this engine also being lubricated by the same oil, no way I'm stretching that interval to 10k miles. I don't care if it's a Toyota. A lot of problems that have developed in modern engines are linked to the the modern extended oil change intervals. Those intervals have a lot more to do with marketing and sales than they do with engineering and mechanics.

 

[185]

first 100 miles is where it gets broken in. Dont overthink the style of driving, just drive it like you normally do.

Dumping the factory fill engine oil is personal preference up until the manual guidelines depending on driving style. Most of us longevity freaks will probably do 500-1k dump the oil, and then switch to a severe duty schedule of 5k/6 months.

Unless your journey is on flat land the entire way, cruise control is actually a pretty good at varying rpms. The issue however, is toyota programming is pretty bad on extended steep inclines so be aware.

 

[stridertexas]

Break in and service intervals given by the manufacturer are determined to fit the statistical likelihood for repairs against their warranties. Not for the perceived longevity a customer wishes to get out of a vehicle.

I dumped oil at 1,200 and will do 5k intervals too. No towing early also. My synthetic oil change was $98 at the dealer : )

 

[TheLCProject]

Break in and service intervals given by the manufacturer are determined to fit the statistical likelihood for repairs against their warranties. Not for the perceived longevity a customer wishes to get out of a vehicle.

I dumped oil at 1,200 and will do 5k intervals too. No towing early also. My synthetic oil change was $98 at the dealer : )

Yup - Precisely. I've done oil analysis on my wife's CR-V at 2,500 and 5,000 miles. The oil was gross looking at 2,500 and I'm glad I did it early (Honda suggests 7,500 miles...) and also bummed I didn't think about getting it done earlier (at 500 or 1,000).

 

[vraa]

I just passed 1000 miles and there is no oil service light yet, I'm going to continue to wait until the service light comes on.

 

[TheLCProject]

I just passed 1000 miles and there is no oil service light yet, I'm going to continue to wait until the service light comes on.

Lexus knows best, right? /sarcasm

Take it in and get the oil changed. Give them a cup and ask them to save a sample for you. Especially since you might be out, as of now, on the formal engine recall. If wear-in contaminants don't drop off precipitously you'd want to know and have it documented.

Or you can trust Toyota/Lexus to do you right.