Why is the Hybrid engine so gutless?

[Sampleman]

I have an XP13 Yaris Hybrid, and the Toyota specs say that this car has a "System Power Output" of 101 hp. Its maximum torque is 270 Nm - so far, so good.

However, I just compared the spec sheets of the two 1.5 liter engines which were sold in this car. The one which is integrated into the Hybrid drive is a four cylinder inline engine with 1,497 cc engine displacement and a compression ratio of 13.5 to one. It is called VVT-i. It reaches its maximum power output of 72 hp at 4,800 rpm and it gives a maximum torque of 111 Nm.

If you do not want to buy the Hybrid, you can get the 1.5 liter VVT-iE engine. It is also an inline four, it has the same engine displacement and the same compression ratio. Both engines have the same service intervals and need the same oil quality: 0W20. I think that both engines more or less are the same in terms of engine size, crankshafts, bore and travel of the cylinders. Both have variable valve timing (VVT).

But the VVT-iE engine is far stronger than the VVT-i engine. It delivers 111 hp instead of 72 hp and 132 Nm of torque instead of 111 Nm. Obviously the VVT-iE engine can toggle between Otto cycle and Atkinson-Miller cycle, and it revs up to 6,000 rpm. As far as I know, the VVT-I chosen for the Hybrid version stays in Atkinson Miller cycle the whole time and it revs up to 4,800 rpm.

So, my question is, how could Toyota squeeze almost 40 hp and additional 21 Nm out of the same engine without using dirty tricks? And why didn't they use the VVT-iE engine also for the Hybrid version?

[FROSTYBALLS]

The 1.5 non-hybrid engine (NR series) wasn't available until 2017. Back in 2016 when your car was new the larger non-hybrid engine was the 1.33, and the later 1.5 non-hybrid was a re-work of the 1.33.

Service intervals - these are common across the majority of the Toyota range (1 year/10,000 miles for the UK and 1 year/15,000km for Europe).

As regards the recommended engine oil, 0W-20 was standardised across the petrol engines from approx 2009/2010 with the introduction of Toyota's Optimal Drive improvements - previously it was for hybrids only.

From 2019/2020, for newer models such as the Corolla, Rav4 hybrids, and the latest Aygos, the recommended engine oil is 0W-16. The recommended engine oil for the new 2020 Yaris (1.5 3 cylinder engine) is 0W-8.

[flash22]

Gutless not really, the hybrid is tuned very differently for economy

same basic engine but the cam's are different and the ECU is tuned

 

The simple reason the hybrid is detuned, is emissions also the lower end torque is dealt with by the electric motor

Edit. Another thought 1NZ-FXE doesn't need extra power as it does not have an Aux belt so in has no load on it from the alternator, A/C or water pump it also doesn't have a traditional starter motor so no need for a ring gear

 

You don't buy a hybrid for its speed/power

[donkeychomp]

Unless it's a Rimac...😁

[bathtub tom]

6 hours ago, flash22 said:

Gutless not really, the hybrid is tuned very differently for economy

same basic engine but the cam's are different and the ECU is tuned

The simple reason the hybrid is detuned, is emissions also the lower end torque is dealt with by the electric motor

 

I could never understand how the hybrid could be so much more economical than the petrol when it has to lug around a heavy Battery and using the engine to charge the traction Battery which then discharges into a motor is hardly efficient. Regenerative braking couldn't account for it. Thanks to flash22 I think I'm beginning to see the light.

So if a hybrid and a petrol were both driven flat out until the hybrid's Battery was discharged, then the petrol would have better performance?

[Sampleman]

I could never understand how the hybrid could be so much more economical than the petrol when it has to lug around a heavy battery and using the engine to charge the traction battery which then discharges into a motor is hardly efficient. Regenerative braking couldn't account for it. Thanks to flash22 I think I'm beginning to see the light.
So if a hybrid and a petrol were both driven flat out until the hybrid's battery was discharged, then the petrol would have better performance?

The additional weight of the electric drive often is vastly overestimated. The Hybrid Battery in my Yaris weights 31 kg, not several hundred kilos like in an EV. The power split device, which acts as a transmission, is lighter than the Multidrive CVT gearbox of the 1.5 VVT-iE. The 12 Volt Battery is smaller and lighter, and the engine neither has a starter nor an alternator. If I remember the specs right, a Yaris Hybrid is even lighter than a Yaris 1.5 VVT-iE with automatic transmission..

The Battery is only charged when the engine has to warm up or during deceleration.

If you compare both cars, the 1.5 VVT-iE is faster. The Hybrid reaches some 103 mph, the gas only car is about 10 mph faster.

However, in my experience, the fuel consumption is most pleasing in situations where you cannot drive constantly at high speeds. Conventional cars become gas guzzlers in heavy city traffic, there the Hybrid excels best. I had the car on German Autobahns and reached average fuel consumptions of more than 7 liter/100 km (40 mpg UK). This is not bad, but it isn't awesome either. In heavy city traffic fuel consumption can go down to 4.5 liter/100 km (62 mpg UK), which I find more fascinating.


Best regards from Bavaria
Frank

[Mick F]

We drove to North Devon and back on Saturday.  50miles each way on rolling Devon hills.  Max speed maybe 60mph and no highways/dual carriageways, just roads. Hills and valleys, bends and narrow bits.  Four or five villages at 30mph limits.

Out of interest, I reset the Ave MPG display when we left home and kept an eye on it throughout.  The average slowly crept up and we made it back home with 64.9mpg showing.

Marvellous!!!

Mick.