Adaptive cruise control and Break-In period

[Toyo67]

What you think it is dangerous to use Adaptive Cruise control  during Break In Engine  by Hybrid Car.

[Cyker]

It's fine, no problem. Engine doesn't really need breaking in, just don't rag it too much.

I took my non-Cross Yaris on a 2 hour hoon after I picked it up to get a feel for it and test out all the functions, including the radar cruse control and auto-steering!

[Primus1]

You don’t really need to run in cars nowadays, engine tolerances and oils are much more advanced from days gone by,

[Toyo67]

My son bought a new Yaris Cross a couple of weeks ago and drove 300 miles from another city. He used adaptive cruise control the whole time with the new car. 

[Cyker]

It's the best thing ever for long boring motorway journeys!  

Makes them much less fatiguing and tedious.

[YarisHybrid2016]

The part of the official run-in guidance that I don't like is "don't drive at constant speed". Well...unless I'm sat on the motorway for hours in the middle of the night, I find that pretty impossible to achieve.

I tend to drive a mix of city and country for the first couple of hundred miles, as it is stop/go traffic with some good 50 MPH stretches. After that, I just drive it normally, while avoiding WOT until I get to 500 miles, then I only do that for a few seconds once it is properly up to temperature.

The major thing is:

Don't go WOT when cold

Don't push it hard when cold

Don't sit on the motorway for the first 300 miles at a constant speed.

From what I've understood of engine run-in, most of it is done before you even get the car! What you're doing is bedding the piston rings to the bore, and all the bearing surfaces to each other, so varying the load is a good thing in the beginning.

[Cyker]

Yeah, it basically boils down to just driving normally and not overly cautiously or like a maniac!  

[Toyo67]

The new engine does not like constant speed, but adaptive cruise control changes number of revolutions  on the highway. 

[MikeSh]

For most cars, manual or DCT/DSG auto the engine rpm at (eg) 70 will be constant. For the Toyota hybrids, and CVTs generally, that isn't the case as the rpm varies with load regardless of the speed being the same. Motorways aren't flat.

So what you should 'do' depends of whether you are running in the engine or gearbox (or wheel bearings or tyres).

With modern manufacturing standards I wouldn't worry at all unless there is specific manufacturer advice, not just dude on the internet stuff.

[MardyMarvin]

16 hours ago, YarisHybrid2016 said:

Don't sit on the motorway for the first 300 miles at a constant speed.

wouldn't that be nice to be able to do a constant speed on a motorway during normal hours 😆

[APS]

16 hours ago, YarisHybrid2016 said:

What you're doing is bedding the piston rings to the bore

That's it. Not bearing surfaces. 

As others have said, it's a bit of a non-issue. Some town driving for the first hour or so is probably a good thing. 

[Toyo67]

The problem is that sometimes you have to buy a new car in a city 300 miles from home.  

[bathtub tom]

7 hours ago, MardyMarvin said:

wouldn't that be nice to be able to do a constant speed on a motorway during normal hours 😆

Easy round here, there's a 50MPH limit on the M1 for miles due to carriageway works.

[Slartybartfast]

Straight from the horses mouth, figuratively. Remember that everything is new, brakes, tyres, suspension etc.. It's not just for bedding the piston rings into their respective bores.

" Breaking in your new Toyota
To extend the life of the vehicle, observing the following precautions is rec-
ommended:
Except hybrid vehicle
 For the first 300 km (186 miles):
Avoid sudden stops.
 For the first 800 km (500 miles):
Do not tow a trailer.
 For the first 1000 km (621 miles):
• Do not drive at extremely high speeds.
• Avoid sudden acceleration.
• Do not drive continuously in low gears.
• Do not drive at a constant speed for extended periods.
Hybrid vehicle
 For the first 300 km (186 miles):
Avoid sudden stops.
 For the first 1600 km (994 miles):
• Do not drive at extremely high speeds.
• Avoid sudden acceleration.
• Do not drive at a constant speed for extended periods"

Rather than do all that, I would just smash a window to break in!

[Toyo67]

The CVS gearbox changes engine rpm even at a constant speed. I turned on Carista live and the rpm of the engine is never at the same parameters.