Hybrid running-in requirements

[pshawfocus]

Am awaiting the delivery date for my Yaris...hoping it's before Xmas.  Was wondering what the running in requirements are?  Used to be something like don't exceed 65mph and no use of full throttle for first 600 miles?    

[Mike J.]

Maximum revs is only around 4800 per minute, so it is never under stress. 65mph is, in general, a good motorway speed - good for mpg and it keeps you out of the HGV zone.

[YarisHybrid2016]

I kept it out of the POWER band for the first 100 miles, and max speed of 50 MPH for the first 1000 miles.

You should never give wide-open throttle to any engine that is cold, so give it 10-15 minutes to warm up first.

It's argued modern engineering doesn't require running in, but I don't agree.

How you look after parts when they're new ("bedding in"), and when they're cold, dictates longevity.

A study done many years ago by Pratt and Whitney, found more harm is done to an engine when it is cold, than in the whole of the rest of its life.

I'm intrigued what effect start/stop has on engine life. When they're in use, the car runs to maintain a minimum temperature, but I can't establish whether it harms the engine more going through start/stop cycles vs. continuous running.

One advantage to the hybrids are how they start - it appears the valves are open (no compression) while the engine is spun-up to starting RPM, then the valves are closed and fuel injected to start it, so it's not turning the engine against compression, and avoids the typical resonant vibration you feel when starting conventional cars.

[Mike J.]

8 hours ago, YarisHybrid2016 said:

One advantage to the hybrids are how they start - it appears the valves are open (no compression) while the engine is spun-up to starting RPM, then the valves are closed and fuel injected to start it, so it's not turning the engine against compression, and avoids the typical resonant vibration you feel when starting conventional cars.

I don't think the system can keep the valves open as you mention. Info on the Prius shows this picture outlining the VVT-i limits - with no overlap on starting:

What is unusual is that the engine is first spun up to around 1000rpm before fuel is 'gently' applied - this gives the smooth and quiet starting.

[Anthony Poli]

With a hybrid having a different setup for starting compared to a non hybrid, you definitely notice it is much quieter. Especially in winter, no hesitation .

I got the impression that the hybrid system, is programmed to stop you from accidentally damaging it. Like if you mash the accelerator into the floor, you can't exceed the safe limit on ice rpm or motor power.

[YarisHybrid2016]

@Mike J.: Thanks for the diagram!

Maybe during *spin-up* it goes to earliest timing, so it sets maximum overlap of intake/exhaust, offloading the engine? Obviously the valves can't be completely open because the piston would collide with the valves, but there definitely seems to be a lack of compression during this moment.

Perhaps once it reaches start RPM it goes to latest timing, then introduces the fuel?

@Anthony Poli: AFAIK there are normal operating limits and a warm-up limit (where the ICE is apparently held at idle even if gently accelerating to 40 or 50 MPH), but I've found if you put your foot down so it goes into the POWER band, even during the  first warm-up phase it will bring in the engine (though it seems to have reduced performance, the RPM certainly comes up). If you leave the POWER band, it goes back to holding idle, until either the HV Battery is low on charge, or the engine has warmed up.

You see this transition in the jump from high instantaneous MPG to low instantaneous MPG.

It doesn't seem however that if you want to use max power from cold, that it will stop you; you just get a reduction in performance as it wastes some energy generating heat to warm things up.

Have you noticed that if you put the cabin heater on a high setting, you get a loss of power even when the ICE has been running over 15 minutes and is warm?

If you get driving at a continuous speed on a flat road, then put the heater on a high setting, it requires the power needle to be higher up the scale to hold speed. When it "cuts out" because the heater is up to temperature, you get a "bump" and increase in acceleration as it is now developing more power, requiring you lift-off slightly to hold speed.

I think when the engine is cold and you put your foot down, it drives like it is warming the heater (reduced power) as it is wasting energy to heat things up.

[Anthony Poli]

Maybe I am just a miser and for my morning commute I try to avoid using the heater apart from clearing the windows. I usually use the heater once the ice has stopped.


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[FROSTYBALLS]

The running in, or breaking in, period is detailed in the full owners manual, which one may download from  https://www.toyota.co.uk/tme#/my-toyota/eManual - see page 205.

Extract copied below:

"Breaking in your new Toyota

To  extend  the life of  the vehicle,  observing  the following precautions  is  recommended:

● For the first 300 km  (200 miles): Avoid sudden stops.

● For the first 1600 km  (1000 miles): • Do not drive at extremely  high speeds. • Avoid sudden acceleration. • Do not drive at a constant speed for  extended periods."

Edited November 14, 2017 by FROSTYBALLS

[pshawfocus]

Thanks for the replies.  I know from my two previous Prii that Toyota hybrids are super smooth and the ICE doesn't start using a conventional starter motor; that coupled with the CVT (one of the best gearbox tyres ever invested IMHO) / hybrid synergy is the appeal - so very linear irrespective of the speed.  I can't recall I ever noticed a drop off of power when I had my heater on, but I guess if either car was very cold I was always gentle during the first 0.5 mile or so, until fluids had gone around. As I'm getting my new Yaris around Xmas I will be extra careful for the first few hundred miles in the lower temperatures.   

[Anthony Poli]

So the Xmas itself won't be as exciting then 

 

[YarisHybrid2016]

You'll probably only notice the slight power drop with heater usage after the car has a few thousand miles on it and you're used to driving it. I notice it because I tend to drive the same roads at the same speeds, so when the power needle is suddenly slightly higher up the scale to hold speed, I notice it. Switching off the heater when I first noticed it proved it, as the car was no longer providing additional heat, so went back to just moving the car, requiring less power.

You'll also find it is VERY sluggish when you first get it. Mine was very tight for the first couple of thousand, but progressively improved. I was passed by everything when I took it home from the dealer as it just didn't accelerate, and I wasn't going to force it to. It was clearly slower than the demonstrator I had driven previously.

Enjoy it! :D

[YarisHybrid2016]

6 hours ago, Anthony Poli said:

Maybe I am just a miser and for my morning commute I try to avoid using the heater apart from clearing the windows. I usually use the heater once the ice has stopped.

I blast the heater on HI if it is frosty to clear the windows, then I turn it down again. I try and run it as low as I can comfortably, though I find in the winter periods I need to run the heater as everything mists up quickly if I don't (particularly at night - daytime doesn't seem so bad - I guess because of the sun). I find it needs to be 19-21 to stop it misting (if it is due to the cold temps).

[Anthony Poli]

1 hour ago, YarisHybrid2016 said:

I blast the heater on HI if it is frosty to clear the windows, then I turn it down again. I try and run it as low as I can comfortably, though I find in the winter periods I need to run the heater as everything mists up quickly if I don't (particularly at night - daytime doesn't seem so bad - I guess because of the sun). I find it needs to be 19-21 to stop it misting (if it is due to the cold temps).

I have mine at 21-22, since the other half doesn't like to be too cold in summer 

 

[YarisHybrid2016]

If OAT is > +5 deg. C then in daytime I run it on LO. 

At night I run it at +16 so it just takes the edge off the coldness of the air (but the car seems to mist up, too, even though the AC is on - weird).