baneling

Hey all, should you still vary the RPMs in a new car for the first 3000 km or so?

nx450plus

Manual goes over break in details such as rpm

baneling

ok thanks i'll check it out.

Droid13

I think the idea is the varying minor to moderate loads will help mate moving surfaces and seat piston rings without overstressing anything. Lots of varying unsustained loads. In other words, don't get on the highway and cruise for 8 hrs as your break in.

mangust

How does one vary RPM on a car with the (e)CVT transmission?...
What about plug-in owners who ride mostly or only electric...
I think Lexus/Toyota could do a better job explaining how to manage a break-in period, if only for people who actually read the manuals

P.S. I have the 450H and went through a few long road trips early on. I found the gas engine become smoother and more refined after a few hundred miles of use.
My recommendation for the plug-in users is to go easy on riding electric only, and try to use the engine for a few hundred miles.

Randyp1234

From a 2022 350 manual.

baneling

thanks for checking.

SgtLip

And DON'T use the Cruise Control for the first 1000 miles.
That falls in line with the don't drive at consistent speed requirement. My ES300h was 500 miles but I saw the NX is 1000 miles. Not sure why the increase in distance between models but I was always told not to use cruise in a new car until broken in.

lexsc4

Bought my wife a 2024 NX350h last month. Drove 400 miles home after picking it up and did all that. I also tried to avoid pedal to the metal acceleration and while on the freeway at 70-75MPH I drove a different speed and RPMs.....No sudden stop, no towing.

Nightlight

With city/suburb driving, it’s difficult to avoid sudden stops with more people who aren’t the best drivers. I’ve had a couple for sure and one this morning. Not hard and neck snapping, but definitely with a fair amount of jerk. The rest have been fine.

Interesting enough, my SA stated that I didn’t need to worry about a break-in period and to drive as normal. I’ll have to follow up and ask on this.

baneling

yes, let us know what he/she says please. my SA didn't say anything about this topic.

Randyp1234

I think our sales guy did too. But he isn't the sharpest knife in the dishwasher.

Smooth2o

Same here. And there’s nothing in the manual about varying rpms.

Droid13

For many people, just going about your normal day is likely to be a perfectly fine break-in. But the SA doesn't really know what normal is for everyone, so they are bound to be right in most cases, but not all. If your idea of normal is hooking up a trailer and car crammed with people and stuff and go on a 12 hr drive, well, this is where a proper break-in first would be wise. Also perhaps if your idea of normal is idling for 2 hrs creeping along in heavy traffic every day. If you are just out and about in everyday city/highway traffic mix you are very likely to be just fine as long as you don't drive like my wife cooks. She ignores all those increments on the stove dial, its either on HI or off, like some people think either the gas or brake pedals need to be to the floor during normal usage.

Droid13

Do not drive at constant speed
Do not drive continuously in low gears.

Following these recommendations will involve varying RPMs. And they don't just want people sitting in the driveway revving the engine, as that isn't what is being implied when people say vary RPMs.

Why is doing both of the above not recommended in the first days (and why simply revving engine in driveway isn't a thing to achieve varying rpm)? Constant speeds, driving in low gears, or simple revving creates situations with very low engine load. That is typically just fine for every day, but you want engine loads (within reason of course) to be present during break-in. Moderate continuously changing loads help make sure microscopic high points in metal to metal contact are smoothed out and help seat piston rings to minimize loss of oil into combustion area.