Engine Break-In for Hybrid Vehicle

[The Critic]

There is a lot of discussion about varying speeds (thereby, load) on a new engine for proper break-in.

On hybrid drivetrains, the vehicle's software will vary the gas and electric motor outputs to deliver the appropriate power needed for the situation. There is no guarantee that varying speeds (while driving) will always vary the engine rpm's.

So how does one "properly" break-in a new hybrid powertrain?

 

[Danh]

Just breaking in a new CRV hybrid and wondering the same thing. Honda’s break-in suggestions are the same as for its conventional vehicles: avoid full throttle acceleration for the first 600 miles.

On Honda hybrids at least, there is a speed where the engine is mechanically linked to the drive axles and performs like a non-hybrid. I suppose driving in this mode (I.e. 45mph +) and varying speeds would allow some traditional break-in opportunities. Even so, by the time the odometer ticks over the 600 miles threshold, how much long and at what revs and load the ICE will have operated is a mystery. Glad break-in isn’t such a big deal anymore.

 

[DirectRejection]

Toyota dealership told me to just drive...no break in.

The Lexus dealership told me the same in 2019.

2024 Corolla Cross Hybrid.
2019 UX 250h.
Both M20A-FXS engines.

 

[The Critic]

Toyota dealership told me to just drive...no break in.

That's what they always say, but both conventional wisdom and the owners manual indicate otherwise.

 

[DirectRejection]

That's what they always say, but both conventional wisdom and the owners manual indicate otherwise.

Yessir. I did vary my driving @ break in.
TGMO 0W16 >> HPL PP 0W8 @ ~400 vehicle miles. I did try flooring it here and there...no tach...lot a good that did SMH.

Point taken The Critic !

 

[Torrid]

I don't know much about breaking in hybrids, mostly because some of them operate much different than others, but I always figured any break in process would end up fairly drawn out if you don't have many longer drives. I can't get a standard ICE vehicle to get the oil to operating temperature putting 2 miles here in there in town even on a warm day, so I can't imagine it wouldn't be much worse for the average hybrid.

 

[spasm3]

Not familiar with hybrid drivetrains, but is there a way you could draw the battery down, then drive it, so it runs on the engine most of the time? Then some full throttle from a dead stop runs, but letting off well before redline?

 

[Propflux01]

I don't think they worry too much about it because the operation taken over by the electric motor will negate any extra wear occurring when a cold engine starts under load after the battery gives it to the I/C portion during the vehicle's expected lifetime.

 

[Torrid]

Not familiar with hybrid drivetrains, but is there a way you could draw the battery down, then drive it, so it runs on the engine most of the time? Then some full throttle from a dead stop runs, but letting off well before redline?

There are cars that you could possibly do this with using different settings for street and track, but I don't think there would be many standard use hybrids that would make this easy. A lot of this is to preserve the battery since extremely low states and high states of charge aren't good for overall battery health.

 

[wpod]

Engines can not help but to break in. I worked on fleet vehicles and all lasted a long time with what ever break in they received.

 

[ragtoplvr]

the traveling carnival guys always have their diesel supplemental power plant. It runs 1200 RPM or nothing. They last many 10's of thousands of hours. They start them, let them run about 30 to 60 seconds and then put them on line. They do not have a heavy load until evening. They will break in just fine. Uber drivers in Vegas do not worry about breakin. I rode in a 300K mile prius that was still perfect.

 

[fdcg27]

There are cars that you could possibly do this with using different settings for street and track, but I don't think there would be many standard use hybrids that would make this easy. A lot of this is to preserve the battery since extremely low states and high states of charge aren't good for overall battery health.

The hybrid's computer will not allow either very high or very low states of charge, unlike with an EV, since controlling state of charge is easy with a big onboard ICE generator and limiting state of charge to a narrow range extends battery pack life.
How could one run the battery as low as the car allows?
Easy, select power on and crank up the AC in the driveway and leave it there for a while. This will deplete the main battery as much as the car's control system will allow after a while and it will remain in EV mode for a surprising amount of time just running the AC and fans.
I concluded quickly when I began driving my HAH that I had little control over the ICE engine, so I gave up on the notion of being able to control break-in running conditions.

 

[meep]

I think a key point is just to go easy on it at first until things have a chance to set in and then increase the romping as it wears in. Ours does have a “auto stick” which doesn’t so much set a ratio as much as it sets an rpm bias. Engine favors a higher somewhat variable ratio in the lower “gears.”

 

[KrisZ]

I don’t buy this “take it easy” break in. Once everything is up to the operating temperature, I go full throttle, just not from the stop or the first gear because that puts the highest amount of torque on the drivetrain, which also needs to break in.

Also, don’t Toyota hybrids have a pretty low redline RPM anyways? It’s a low stressed engine, no need to baby it IMO.

 

[JHZR2]

Ive always taken break in to be more of a drive gently perspective than anything. That and don’t stay at one engine speed for long times (not really an issue with hybrids).

So I’d do just thst, go easy, let it all get working together.

The one thing I woukd be considerate of is allowing some high vacuum closed throttle coasting. Hybrids will regen, so to force this you likely need some long hills that you can start at high battery SOC, so it fills completely and then forces the engine on. What kind of a car? My Honda will do this, I’ve done it a few times on purpose….