[ferrarirules]

With the rising popularity of EVs, Hybrid tech is also gaining traction. There is a lot of talk on the forum regarding different Hybrid options and their pros and cons. So here is thread to cover all the different hybrid drive train options.

The hybrid powertrains can be represented in the following diagram

Parallel Hybrid

Parallel hybrids have a electric motor, internal combustion engine (ICE) and a small battery. They are of two types of implementation in parallel hybrids

1. Parallel Hybrid aka Mild Hybrid

These vehicles have a small Li-Ion battery which is integrated with Integrated Starter Generator. The car has regenerative braking to charge the small battery. This helps in the followings functions

1. Auto Start/Stop - The engine shuts down when the car is idling and starts it up when you want to move ahead
2. Torque assist to the ICE

Pros:
1. Slightly higher fuel efficiency than pure ICE

Cons:
1. No pure electric drive capability
2. No major reduction in tail pipe emissions
3. Engine cranks every time you start the car, no silent start up.
4. Annoying engine shutdown and startup in traffic

Examples - Maruti Smart Hybrid or Toyota Neodrive used in cars like XL6, Fronx, Brezza, Grand Vitara and Hyryder

2. Series - Parallel Hybrid aka Strong Hybrid

These vehicles have a small Li-Ion battery (around 1 KW) which is integrated with a electric motor plus there is a ICE. Both the ICE and electric motor can power the wheels using a power split device and planetary gear. The car has regenerative braking to charge the small battery. There are different scenarios in which either ICE or electric motor or both power the car -

1. Dedicated EV mode which gives 2 - 3 kms range under light acceleration and at speeds under 40 kmph
2. Electric motor powers the wheels and engine charges the battery in constant speed drive conditions below 75-80 kmph
3. Electric motor plus ICE power the wheels under normal acceleration
4. Heavy acceleration or speeds above 80 kmph - Petrol motor powers the wheels

Pros:

1. Higher fuel efficiency than a pure ICE or mild hybrid car which entails to lower running cost
2. Lesser per km emissions than pure ICE car or mild hybrid car

Cons:
1. Very limited pure electric drive capability
2. Still pollutes the urban areas
3. Complex setup needs more components and algorithms to switch between motor and ICE.
4. Uses eCVT gearbox
5. Costs more than Mild hybrid or Pure ICE car. Example - Toyota Hyryder mild hybrid V AT is Rs. 17.24 lakh ex- showroom and strong hybrid V AT is Rs. 19.99 lakh ex-showroom

Examples - Toyota Hybrid or Honda e:HEV (Honda has a slightly different implementation) used in cars like Maruti Grand Vitara, Toyota Hyryder or Honda City

Series Hybrid aka Range extended electric vehicle

These hybrids also have a battery (slightly larger than a series parallel hybrid vehicle), electric motor and ICE. The difference being the ICE act as a generator and the wheels are only powered by the electric motor. The car has regenerative braking to charge the battery. The tech is currently implemented by Nissan currently in its e-Power cars. Nissan uses 2.1 KWH battery to power the electric motor. The battery is charged as required by a 1.5 L variable compression ICE. It can vary its compression between 8:1 to 14:1 for different driving conditions. Lower compression for heavy driving and higher compression for sedate/steady driving conditions

Pros:
1. Better thermal efficiency as the ICE operates in optimal RPMs.
2. Higher fuel efficiency than a pure ICE or mild hybrid car which entails to lower running cost
3. Lesser per km emissions than pure ICE car or mild hybrid car
4. Lesser complexity than a series parallel hybrid
5. No gearbox needed

Cons:
1. Very limited pure electric drive capability
2. Still pollutes the urban areas
3. 95 RON fuel required due to variable compression

Examples - Nobody is selling mass market series hybrid cars in India. Maruti is talking about bringing series hybrid in Fronx in 2025. Nissan sells series hybrid cars outside India.

Plugin Hybrid

These hybrids are nothing but series parallel hybrid or series hybrid with a larger battery. The battery can charged from an external power source. These cars have an electric only driving range of 50 to 75 kms on a single charge. And if the battery gets depleted, it behaves like any other hybrid car.

Pros:
1. Pure electric range sorts out most of the city driving uses cases
2. Occasional hybrid trips can be made without the need of charging the car
3. Higher fuel efficiency than a series parallel or series hybrid car. Running cost in the city can be near to EVs and on highways near to other hybrid vehicles
4. Lesser per km emissions than pure ICE car or mild hybrid car or strong hybrid car.

Cons:
1. In city, the car lugs around an ICE adding to extra weight
2. On highways, the car lugs around a larger battery adding to extra weight
3. If the user doesn't charge the battery, it still pollutes the urban areas
4. If the user doesn't charge the battery, the fuel efficiency numbers will go for a toss
5. Need to visit the fuel bunk to fill up the petrol tank.

Examples - Nobody is selling mass market plugin hybrid cars in India. MG has hinted on bring PHEVs to India.

Some history of different hybrids being covered on Teambhp

1. Teambhp was invited for a Toyota Hybrid event in Japan in 2013. Toyota showcased both Strong Hybrid and Plugin Hybrid. Toyota launched mass market hybrid in India in 2022 - Related thread (Toyota Hybrid Technology: Drive & Experience @ Japan)
2. Nissan note e-Power was caught testing in India in 2017. Nissan never launched the product in India - Related thread (Nissan evaluating e-Power tech for India. EDIT: Note spotted!)
3. Plugin Hybrid for India? - The thread discussion was started in 2020. Not even one mass market plug in hybrid was launched in India. - Related thread (Plug-in Hybrids for India?)

Finally the question - Out of these which hybrid power train will you prefer or will you prefer an EV or will you prefer pure ICE - NA/turbo petrol/diesel

--Image credits to respective owners--

[fordday]

Good read.

Originally Posted by ferrarirules

2. Torque assist to the ICE[/left]
[/left]

Can you please explain what happens here and how? I don't see a electric motor here.

[ferrarirules]

Originally Posted by fordday

Good read.
Can you please explain what happens here and how? I don't see a electric motor here.

This is how it works

Maruti Suzuki's Smart Hybrid aka mild hybrid Technology uses an Integrated Starter Generator (ISG) to provide torque assist to the engine during acceleration. The ISG replaces the conventional starter motor and alternator, and uses energy stored in the car's dual battery setup to help the engine. This reduces the load on the engine, which improves fuel efficiency and performance

[Joe367]

Another disadvantage of strong hybrid cars is that the battery eats into the cabin space

[Tensor]

Originally Posted by fordday

Good read.



Can you please explain what happens here and how? I don't see a electric motor here.

In a parallel hybrid or mild hybrid configuration, a compact lithium-ion battery works in conjunction with an Integrated Starter Generator (ISG). The ISG functions as a smaller electric motor, it is weaker than those used in full hybrid or electric vehicles

1. Auto Start/Stop: - To save fuel, the technology automatically switches off the internal combustion engine (ICE) while the car is at standstill - The ISG rapidly restarts the engine after the brake is released or the accelerator is depressed, allowing for a smooth departure. Regenerative braking charges back the small battery's energy reserves.

2. Torque Assist to the ICE: - Torque assist involves the ISG delivering a slight power boost to the internal combustion engine during acceleration. - Although the ISG is not a full-fledged electric motor, it can provide torque at specific times, removing some of the strain on engine, The ISG utilizes power from the lithium-ion battery for this temporary boost, leading to reduced fuel consumption.

[gopalnt]

One aspect of Strong Hybrid, PHEV and EV cars is that the battery life goes down with usage and they may not provide the same efficiency, let's say in 5th year compared to 1st year. Also, they have to be replaced at some point of time which is going to cost few lakhs.

So the initial cost is high and thats not going to end as one-time expense. It is going to blunt any saves on fuel that we are looking at. Also, from India's perspective, while for ICE we are dependent on fuel from Middle East or Russia, for batteries we may have to depend on China (not manufacturing but raw material itself).

I would rather depend on ME/Russia rather than China at any point of time.

[SithDefender]

I have a question about this : Why does the Hycross have a lower fuel efficiency figure than the City hybrid/ Hyryder? Is it just because of the additional weight that the Innova has to haul? I have heard 13-15 kpl for the Hycross, and 25+ for the City hybrid. Could someone pls explain ?

[Phantom 510]

Originally Posted by SithDefender

Attachment 2647528

I have a question about this : Why does the Hycross have a lower fuel efficiency figure than the City hybrid/ Hyryder? Is it just because of the additional weight that the Innova has to haul? I have heard 13-15 kpl for the Hycross, and 25+ for the City hybrid. Could someone pls explain ?

The Innova Hycross is a much larger vehicle. It is neither light nor aerodynamic as the other two which increases drag. Drag is the biggest enemy of efficiency. Fuel mileage of 13 to 15 kmpl from a full size hybrid MUV is still very respectable. That figure could be stretched further with sane driving manners by atleast 2-3 kmpl. It's extremely fuel efficient for it's size IMO.

[SR-71]

Originally Posted by ferrarirules

Parallel Hybrid
Examples - Maruti Smart Hybrid or Toyota Neodrive used in cars like XL6, Fronx, Brezza, Grand Vitara and Hyryder

<snip>

[b]2. Series - Parallel Hybrid aka Strong Hybrid
Examples - Toyota Hybrid or Honda e:HEV (Honda has a slightly different implementation) used in cars like Maruti Grand Vitara, Toyota Hyryder or Honda City

Insightful article, just one question, you have used "Grand Vitara and Hyryder" as an example under both mild hybrid and strong hybrid. Do these vechicles ship with both types of engines?

[vinya_jag]

Voted for PURE ICE
We are consciously trying to reduce Car usage in our family. This is mostly because of how the traffic around us is shaping up.
We take out our big car only on long drives which is kind of limited to around 5000Kms in a year. Our Workhorse Polo Diesel does the daily duties, which again has been limited by car pooling for routine drives, so the usage is down to around 50Kms per week (2500-3000Kms per year)

Newer cars are not getting any better dramatically anymore, other than powertrain and Gizmos. So, stick to your existing cars as long as it allows you to, fix dents, service them regularly, repaint.

And when the time comes to really really replace your car, a clean and efficient ICE car would do for us.
Added premium of 3-4 Lakhs (Considering a Honda City) for a Hybrid, and a similar premium for EVs too, I don't see a way how it would make economic sense for such low usage.

I agree, if you want the fun of driving an electric car, or if one likes the silent nature of those cars, or if there is no ICE model for a car that you love, you go for the alternate powertrains. But for most, it is the ICE that would make more sense. (YET)

[madrocket]

Insightful article, just one question, you have used "Grand Vitara and Hyryder" as an example under both mild hybrid and strong hybrid. Do these vechicles ship with both types of engines?

Yes. Both the Grand Vitara and the Hyryder are available as mild and strong hybrid versions.

[riteshritesh]

Nice information. Is there any difference between the ISG that Kia Seltos IVT has and the Mild Hybrids of Suzuki /Toyota ( Ciaz/XL6 and the gang).
I haven't seen any 'special' fuel efficiency on my Seltos nor is there any on the Ciaz in the family. I get 6~7 kmpl on the Kia IVT with ISG and 6~7 kmpl on a pure ICE Honda City CVT or the CVT BRV or a CVT Glanza. This is for a daily 2 km to and 2 kms fro drive to work.

[RGK]

This might be somewhat basic.

I drove an Ertiga Hybrid a few days ago, and when the engine started, the RPM increased to 1500 before lowering after a few minutes. Is this typical for all hybrids? What is the reason for this behavior?.

[nandrive]

Originally Posted by ferrarirules

2. Series - Parallel Hybrid aka Strong Hybrid
[left]These vehicles have a small Li-Ion battery (around 1 KW) which is integrated with a electric motor plus there is a ICE. Both the ICE and electric motor can power the wheels using a power split device and planetary gear. The car has regenerative braking to charge the small battery.

Not only the regenerative braking charges the battery, ICE also charges the battery.

Originally Posted by Joe367

Another disadvantage of strong hybrid cars is that the battery eats into the cabin space

Not really, I own a Toyota Rav4 Hybrid, its cargo capacity, fuel tank capacity, cabin space are exactly same as its ICE counterpart.

[ashivas89]

Nice post OP.

For the sake of completeness i'd like to add the fact that the biggest premise of both series and parallel strong hybrid systems these days is the non conventional combustion cycle of the ICE. This is what enables mind boggling fuel efficiency. The ICE in a hybrid powertrain does not bear the burden of "moving" the car by itself. Therefore, it can run on torque deficient but efficient combustion cycles.

Another point is that the Honda hybrid system operates as a series hybrid for the most part and a pure ICE powertrain (via a direct clutch) for a very brief part of the speed range.