Why no 1.5 i3 for the hybrid?

[ElMaverick]

I'm driving around in a rented escape and all I can think of is why didn't they combine the i3 with the hybrid, since it's smaller and more powerful than the 2.5...

I'm also a bit worried about how future proof the 2.5 is, it still seems like too big of an engine for the power it provides and role that it plays, as hybrid technology progresses, won't most hybrids just use a tiny engine as a generator and not for power?

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[SpacemanSpiff]

For a hybrid, it’s not how small the ICE is, but how efficient it is. The 1.5l has a turbo, which by its very nature is less efficient when under hard acceleration compared to a normally aspirated engine. In addition to being normally aspirated (no turbo) the 2.5l uses a slightly different combustion cycle known as the Atkinson combustion cycle, which is more efficient, but can be lackluster in performance, especially from a stop. Which makes it perfect to pair with an electric motor as e-motors have great amounts of torque to get a vehicle moving.

 

[motoretro]

I'm driving around in a rented escape and all I can think of is why didn't they combine the i3 with the hybrid, since it's smaller and more powerful than the 2.5...

I'm also a bit worried about how future proof the 2.5 is, it still seems like too big of an engine for the power it provides and role that it plays, as hybrid technology progresses, won't most hybrids just use a tiny engine as a generator and not for power?

From my research and understanding, the 2.5 is a real solid engine that has stood the test of time. I believe it's listed by Wards as one of the ten best. Due to it's proven long term durability over time I'm guessing it's less expensive to build and operate than the 3 cylinder turbo and makes the type of power required to accommodate the hybrid platform. Initially I thought there would be three different drivetrains w/ the Hybrid in the middle or even in step with the 2.0. Ford really tossed a curve with a sub 20K Hybrid starting point. I'm sure as things progress, a smaller engine will surface.

 

[balucipher]

Pulling the old but reliable 2.5L and mating it with the hybrid drive keeps costs low and reliability high. I'm not sure I would have been down for a 3cyl turbo hybrid - that's a complex set up

 

[oljackfrost]

The operating characteristics of a turbo really don’t match up well with the low revving nature of a hybrid setup.

 

[fbov]

... why didn't they combine the i3 with the hybrid, since it's smaller and more powerful than the 2.5...

It's a bad fit with a power split transaxel. Hyundai is advertising one, but their hybrids are conventional drivetrains with a low-speed motor in-line and a really big, belt-driven alternator (based on 2016 Sonata Hybrid).

It's also going the wrong way... turbo engines suck gas like much larger engines. Atkinson-cycle makes an engine smaller (on the intake side).

Remember, most cars throw away 70% of the energy in gasoline. Imagine a 70% tax rate; you get $0.30 on the dollar. I get $0.40...

 

[Red Ryder]

I would have passed had the 1.5L 3-cylinder been the powerplant. I didn't even want a turbo much less the wet-timing belt 3-popper.

The MZR-based 2.5 Hybrid is ideal for this application. I had the 2.3L in a vehicle for well over a quarter million miles with no issues I couldn't take care of at home. That 3-cylinder is not "future proof", rather a low-cost option for Ford to bridge a gap before going electric.

 

[OldNavyGuy]

Just traded a 2010 Mercury Mariner Hybrid for a 24 Maverick Lariat Hybrid. The same 2.5 Atkinson Cycle motor was in the Mariner. Absolutely zero problems with that motor in 107K miles. For me, one of the big draws for the Maverick was getting the same 2..5 ICE again. I wouldn’t have touched it with a three cylinder twin turbo. I do miss the tachometer in the Mariner, though. It functioned as a good ECO coach. I always knew when the engine was running, and could set a specific RPM for acceleration as needed. Worked great and gave as much info as the power meter.

 

[wax87]

The operating characteristics of a turbo really don’t match up well with the low revving nature of a hybrid setup.

Why do you think that, not trying to argumentative but turbos need RPM to spool up, so marrying it up to an electrical motor which is good at low end to a turbo that is good at high end seams to be reasonable to me...

 

[cyberdog]

Ask a Ford mechanic what they think of the 1.5 & older 2.0 EcoBoost engines. Spoiler alert, they don't like them, way too many problems, especially with blown head gaskets. Now add the constant start/stop of a Hybrid setup, where the block/head are constantly being heated, allowed to cool, and being heated again over and over.

By sticking with a NA Engine setup, they're heavily improving durability and longevity of the engine. Not to mention, woohoo no DI valve deposits, as it uses a form of PFI.

 

[Darnon]

Why do you think that, not trying to argumentative but turbos need RPM to spool up, so marrying it up to an electrical motor which is good at low end to a turbo that is good at high end seams to be reasonable to me...

Not like an electric motor is necessarily lacking at high end power either; look at a Tesla Plaid, Lucid, etc.

There certainly are high performance hybrids that use forced induction (for instance Mazda's Skyactiv-X), but if cost-savings is the goal then you work against that by building a more complex powertrain.

 

[wax87]

yes they can be, but torque is required at low speed which is where the electric motors excel and ICE struggle and we are talking hybrids not EV's

 

[Darnon]

yes they can be, but torque is required at low speed which is where the electric motors excel and ICE struggle and we are talking hybrids not EV's

The same principle applies though: a suitably sized electric motor can output plenty of power. So where the ICE makes peak power doesn't really matter, you can just shunt it to the electric motor. That's where a CVT helps because the crankshaft speed doesn't need to be directly correlated to the transmission output speed like a traditional transmission.

Turbocharged engines are only relatively efficient compared to a larger N/A motor of similar power output because they can also act as a variable displacement at low load. Getting a smaller volume of air/fuel to the sufficient pre-ignition pressure in relation to the volume of the power stroke. But that pressure still isn't a free lunch since it's taking power to spin the turbine which then gets turned into heat in the incoming air charge and usually gets dumped via an intercooler. Therefore it is power 'lost' not propelling the vehicle.

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