Unique Hybrid Set-Up in the New 2024 Lincoln Nautilus

[RedHoncho01]

On 3/21/2024 at 4:54 PM, Rick73 said:

Do you think that’s due to Atkinson-cycle engine design in general, or possibly the Ford 2.5L 4-cylinder Atkinson specifically, and or in this application?

 

An engine with only +/- 162 HP will have to work pretty hard to power a 4,400 vehicle, so it’s not entirely surprising that it may be a little loud and rough at times.

 

Anyway, my personal opinion for quite a while has been that Ford needs a larger-displacement higher-horsepower Atkinson engine for heavier vehicles.  I would guess the 2.5L Atkinson does better in lighter vehicles where it doesn’t have to work as hard, and therefore engine speed can remain lower on average.  That would help reduce noise, vibration, and harshness.

I think it is the Atkinson engine.  The 2.5L Atkinson has been the standard engine Ford has used on all hybrids and the Corsair GT until the launch of the Aviator GT and now the 2024 Nautilus.

[Rick73]

2 hours ago, RedHoncho01 said:

I think it is the Atkinson engine.  The 2.5L Atkinson has been the standard engine Ford has used on all hybrids and the Corsair GT until the launch of the Aviator GT and now the 2024 Nautilus.

Between Ford, Toyota, Honda, Hyundai, Kia and others, I expect there are literally millions of Atkinson engines in use, and I haven’t seen that many reports on noise.  Maybe I just missed most of them.  I did a Google search and found a thread on Maverick Hybrids sounding loud, particularly in cold weather, but it seems the issue is with throttle body getting stuck (or so some posters claimed) which also caused check engine light to come on.  This sounds more of a specific engine issue than Atkinson design issue to me.  For what it’s worth, a couple of owners with EcoBoost reported similar noise issue.  I recall at least one EB Maverick owner here mentioning engine was loud, so not limited to Atkinson.

 

https://www.mavericktruckclub.com/forum/threads/noisy-engine-in-cold-temperature-start.25856/page-2
 

As we all know an Atkinson engine makes less power and torque for its displacement, so a 2.5L will have to rev higher on average — as if it was a 2.0L engine (approximately).  With roughly 160 HP and 155 lb-ft of torque, I expect a 2.5L 4-cylinder will get busy (and loud) at times if installed in a heavier vehicle.

 

Another factor that should help a lot is if Ford upgrades Atkinson engine to a much longer stroke-to-bore ratio.  This change should improve combustion and could lead to less noise.  I still believe that the “all-new” Mustang 2.3L engine with 84 mm bore and 102 mm stroke should make a superior Atkinson engine than the older 2.5L presently used in Maverick and other compact hybrids.  For larger vehicles, at least RWD, an inline-6 variant with greater displacement would be more appropriate in power and torque.

 

 

[akirby]

53 minutes ago, Rick73 said:

Between Ford, Toyota, Honda, Hyundai, Kia and others, I expect there are literally millions of Atkinson engines in use, and I haven’t seen that many reports on noise.  Maybe I just missed most of them.  I did a Google search and found a thread on Maverick Hybrids sounding loud, particularly in cold weather, but it seems the issue is with throttle body getting stuck (or so some posters claimed) which also caused check engine light to come on.  This sounds more of a specific engine issue than Atkinson design issue to me.  For what it’s worth, a couple of owners with EcoBoost reported similar noise issue.  I recall at least one EB Maverick owner here mentioning engine was loud, so not limited to Atkinson.

 

https://www.mavericktruckclub.com/forum/threads/noisy-engine-in-cold-temperature-start.25856/page-2
 

As we all know an Atkinson engine makes less power and torque for its displacement, so a 2.5L will have to rev higher on average — as if it was a 2.0L engine (approximately).  With roughly 160 HP and 155 lb-ft of torque, I expect a 2.5L 4-cylinder will get busy (and loud) at times if installed in a heavier vehicle.

 

Another factor that should help a lot is if Ford upgrades Atkinson engine to a much longer stroke-to-bore ratio.  This change should improve combustion and could lead to less noise.  I still believe that the “all-new” Mustang 2.3L engine with 84 mm bore and 102 mm stroke should make a superior Atkinson engine than the older 2.5L presently used in Maverick and other compact hybrids.  For larger vehicles, at least RWD, an inline-6 variant with greater displacement would be more appropriate in power and torque.

 

 

Don’t you think if it was feasible to run a 6 cylinder atkinson cycle engine that someone would have done it already?

 

Im guessing that a 4 cylinder turbo is just as efficient as a 6 cylinder Atkinson and provides more power when needed.

[Rick73]

38 minutes ago, akirby said:

Don’t you think if it was feasible to run a 6 cylinder atkinson cycle engine that someone would have done it already?

 

Im guessing that a 4 cylinder turbo is just as efficient as a 6 cylinder Atkinson and provides more power when needed.

They have, and are presently doing so as far as I know.  Chrysler Pacifica PHEV uses an Atkinson variant of 3.6L Pentastar.  That same engine is expected to power upcoming PHEV 1/2-ton RAM pickup.  The Pentastar is relatively old and not ideal geometry for Atkinson cycle operation, so we should keep that in mind.  Mercedes and others have built V6s also.  

 

I believe you were the one who said few buyers purchasing $80k luxury vehicles will care that much about fuel economy, which I agree.  Plus it’s really difficult to install an inline-6 engine transversely in FWD vehicle, leaving 4s by default.  Manufacturers will have to want to improve fuel economy in order to meet government regulations before they invest in new engines; assuming BEV sales don’t rebound significantly and put an end to all ICE investment.

 

An important question IMO will be whether manufacturers see enough time prior to sufficient BEV adoption to invest in development of new engines optimized for hybrid powertrains.  The Mustang’s new 2.3L makes a lot of sense to me to convert to Atkinson for vehicles no heavier than Maverick.  A 6-cylinder variant in 3.4L range perhaps could handle vehicles 1,000~1,500 pounds heavier, maybe more.

[akirby]

1 hour ago, Rick73 said:

They have, and are presently doing so as far as I know.  Chrysler Pacifica PHEV uses an Atkinson variant of 3.6L Pentastar.  That same engine is expected to power upcoming PHEV 1/2-ton RAM pickup.  The Pentastar is relatively old and not ideal geometry for Atkinson cycle operation, so we should keep that in mind.  Mercedes and others have built V6s also.  

 

I believe you were the one who said few buyers purchasing $80k luxury vehicles will care that much about fuel economy, which I agree.  Plus it’s really difficult to install an inline-6 engine transversely in FWD vehicle, leaving 4s by default.  Manufacturers will have to want to improve fuel economy in order to meet government regulations before they invest in new engines; assuming BEV sales don’t rebound significantly and put an end to all ICE investment.

 

An important question IMO will be whether manufacturers see enough time prior to sufficient BEV adoption to invest in development of new engines optimized for hybrid powertrains.  The Mustang’s new 2.3L makes a lot of sense to me to convert to Atkinson for vehicles no heavier than Maverick.  A 6-cylinder variant in 3.4L range perhaps could handle vehicles 1,000~1,500 pounds heavier, maybe more.

Again, in heavier vehicles I would bet a 1.5 or 2.0 ecoboost is more fuel efficient than a 3.5-ish liter Atkinson cycle.  

[Rick73]

57 minutes ago, akirby said:

Again, in heavier vehicles I would bet a 1.5 or 2.0 ecoboost is more fuel efficient than a 3.5-ish liter Atkinson cycle.  

I’d take that bet.  EcoBoost specific fuel consumption is relatively poor under heavy loads, so having an EcoBoost that is small for the vehicle size can easily end up being worse than one a little larger.  We can even see that trend when comparing EcoBoost against naturally aspirated ICE.  Lightly loaded EB in F-150 wins but when towing large trailers data shows V8 can be as efficient or more so.

 

In any case, Atkinson engines generally have higher efficiency and lower Brake Specific Fuel Consumption (BSFC).  There is a reason Ford, Toyota, Honda and Hyundai/Kia use so many Atkinson engines in their highest MPG hybrid vehicles.

 

I seriously doubt Ford will come out with a larger Atkinson engine for larger hybrids, but I would sure like to see one. 😆 

[smsfordman]

11 hours ago, RedHoncho01 said:

My understanding is if you put the vehicle in the EXCITE drive mode there is some sort of tachometer showing in the display.  My Corsair GT will show a tachometer along with a graphic showing how much power the ICE and electric motors are using as well as how much charge is being put back into the HV battery when decelerating or braking.

Unfortunately the Hyrids do not have the tachometer in Excite mode.

[silvrsvt]

12 hours ago, Rick73 said:

I’d take that bet.  EcoBoost specific fuel consumption is relatively poor under heavy loads, so having an EcoBoost that is small for the vehicle size can easily end up being worse than one a little larger.  We can even see that trend when comparing EcoBoost against naturally aspirated ICE.  Lightly loaded EB in F-150 wins but when towing large trailers data shows V8 can be as efficient or more so.

 

In any case, Atkinson engines generally have higher efficiency and lower Brake Specific Fuel Consumption (BSFC).  There is a reason Ford, Toyota, Honda and Hyundai/Kia use so many Atkinson engines in their highest MPG hybrid vehicles.

 

I seriously doubt Ford will come out with a larger Atkinson engine for larger hybrids, but I would sure like to see one. 😆 

 

But you also lose about 20% or so of your overall power using an Atkinson style engine. Hybrid engines aren't pure Atkinson engines either. They only use part of the cycle. 

In the grand scheme of things people don't tow all the time (well in non fleet usage) so the light duty of just moving a truck will be appreated. 

 

Your max efficiency bias is showing again too. 

[akirby]

14 minutes ago, silvrsvt said:

Hybrid engines aren't pure Atkinson engines either. They only use part of the cycle.

Says who?

[CurtisH]

10 hours ago, smsfordman said:

Unfortunately the Hyrids do not have the tachometer in Excite mode.

Regular Corsairs have the tach in Excite mode.  There is also an option in the settings to display the tach in all modes.  Maybe the hybrid Corsair also has that option.

[silvrsvt]

16 minutes ago, akirby said:

Says who?

 

from Wikipedia

 

Quote

In the late 20th century, the term "Atkinson cycle" began to be used to describe a modified Otto-cycle engine—in which the intake valve is held open longer than normal, allowing a reverse flow of intake air into the intake manifold. This "simulated" Atkinson cycle is most notably used in the Toyota 1NZ-FXE engine from the early Prius and the Toyota Dynamic Force engines.

 

The effective compression ratio is reduced—for the time the air is escaping the cylinder freely rather than being compressed—but the expansion ratio is unchanged (i.e., the compression ratio is smaller than the expansion ratio). The goal of the modern Atkinson cycle is to make the pressure in the combustion chamber at the end of the power stroke equal to atmospheric pressure. When this occurs, all available energy has been obtained from the combustion process. For any given portion of air, the greater expansion ratio converts more energy from heat to useful mechanical energy—meaning the engine is more efficient.

 

The disadvantage of the four-stroke Atkinson-cycle engine versus the more common Otto-cycle engine is reduced power density. Due to a smaller portion of the compression stroke being devoted to compressing the intake air, an Atkinson-cycle engine does not take in as much air as would a similarly designed and sized Otto-cycle engine. Four-stroke engines of this type that use the same type of intake valve motion but using forced induction to make up for the loss of power density are known as Miller-cycle engines.

 

Its semantics, but its not an Atkinson engine-an Atkinson style of engine due to the intake. 

Edited March 25 by silvrsvt

[akirby]

2 hours ago, silvrsvt said:

 

from Wikipedia

 

 

Its semantics, but its not an Atkinson engine-an Atkinson style of engine due to the intake. 

Still an Atkinson cycle engine as opposed to an Otto cycle.

[Rick73]

4 hours ago, silvrsvt said:

But you also lose about 20% or so of your overall power using an Atkinson style engine.

True, but so what?  You seem stuck on this as if there is no fix for it.  What’s the real and practical downside to making most engines a little larger in displacement if that’s what it takes?  Adding 25% displacement for Atkinson to equal power of Otto cycle isn’t the end of the world.  I can think of various engine families where displacement varied considerably with little or no external engine-size differences.  For example, is the 2.5L Atkinson in Maverick that much larger or heavier than a comparable 2.0L Otto?

 

Comparing Atkinson to EcoBoost instead of Otto gets more complicated, but would a hypothetical Hybrid Maverick with 1.5L EcoBoost allow truck to be made smaller because engine is more compact (not that anyone wants a smaller Maverick)?  Would truck weigh less?  Would truck cost less?  Would it save on gas?  Would it cost less to repair long-term?  Even if any of these was yes, differences would be very minor.  I think you’re worried about an issue that’s not a big deal to overcome, other than it cost money to design and build a new larger Atkinson engine.

[akirby]

1 hour ago, Rick73 said:

You seem stuck on this

Oh the irony….

[silvrsvt]

1 hour ago, Rick73 said:

True, but so what?  You seem stuck on this as if there is no fix for it.  What’s the real and practical downside to making most engines a little larger in displacement if that’s what it takes?  Adding 25% displacement for Atkinson to equal power of Otto cycle isn’t the end of the world.  I can think of various engine families where displacement varied considerably with little or no external engine-size differences.  For example, is the 2.5L Atkinson in Maverick that much larger or heavier than a comparable 2.0L Otto?

 

Comparing Atkinson to EcoBoost instead of Otto gets more complicated, but would a hypothetical Hybrid Maverick with 1.5L EcoBoost allow truck to be made smaller because engine is more compact (not that anyone wants a smaller Maverick)?  Would truck weigh less?  Would truck cost less?  Would it save on gas?  Would it cost less to repair long-term?  Even if any of these was yes, differences would be very minor.  I think you’re worried about an issue that’s not a big deal to overcome, other than it cost money to design and build a new larger Atkinson engine.

 

here is the problem:

Typical 3L class V6 makes anywhere from say 300-400HP, lets lop off 20-25% of the power with an Atkinson cycle, so your down 75-100HP.

 

The difference between the Otto cycle 2.5L and 2.0L I4 from Ford is about 175hp/172 (2.5) and 166hp/149 (2.0L)

 

The Atkinson 2.5L drops to 156/136 (11% HP loss and 21% torque loss using the fusion hybrid as an example) but combined with the hybrid motor, it goes up to 191HP (apparently the motors don't count towards torque)

 

So in the I4 hybrid, the hybrid motor can make up and add to the power loss that an atkinson cycle has.

 

In a V6 application, using the Powerboost as an example, the motor in it is only good for 47HP, which means your still down a considerable amount of power. 

 

TLDR: Atkinson cycle V6s lose too much power to make them effective Hybrids in the sense that you'll see MPG savings like a I4 engine.

 

 

 

 

 

[akirby]

42 minutes ago, silvrsvt said:

TLDR: Atkinson cycle V6s lose too much power to make them effective Hybrids in the sense that you'll see MPG savings like a I4 engine.

And that’s why I said a small ecoboost would probably work better.

[DudaSpringHill]

On 3/20/2024 at 8:27 AM, Gurgeh said:

There is no power flow display, at least none that I am aware of, despite what the owners manual says. Maybe it is an app that wasn't quite ready for launch, or maybe they just changed their mind. There are lots of apps that could be available, I think. One I had on my 2019 Nautilus that I often had displayed in the driver's info cluster was what tires were receiving power (and how much) at any given time. You could see on easy highway driving when power disconnected to the rear wheels for improved fuel efficiency and the surge of power on acceleration. It provided mostly useless info but it was cool to look at (I would put power flow in the same category). I suspect we'll see additional apps becoming available over time. But we'll see.

My 2024 Nautilus Hybrid doesn’t have the Power Flow or Power Gauge apps / on screen information as referenced in the Owners Manual, either.  I’m curious as to whether this is a feature that was supposed to be provisioned on the hybrid models by the dealer at delivery, but was missed?

[DeluxeStang]

On 3/24/2024 at 1:08 PM, Rick73 said:

Between Ford, Toyota, Honda, Hyundai, Kia and others, I expect there are literally millions of Atkinson engines in use, and I haven’t seen that many reports on noise.  Maybe I just missed most of them.  I did a Google search and found a thread on Maverick Hybrids sounding loud, particularly in cold weather, but it seems the issue is with throttle body getting stuck (or so some posters claimed) which also caused check engine light to come on.  This sounds more of a specific engine issue than Atkinson design issue to me. 

 

 

The hybrids are a little loud during cold startup, but most cars are fairly loud during cold startups. I highly doubt it's the throttle bodies getting stuck open, they would have discovered something like that in testing, and in the 15 years or so that the 2.5 has been on the market. 

[smsfordman]

8 hours ago, DudaSpringHill said:

My 2024 Nautilus Hybrid doesn’t have the Power Flow or Power Gauge apps / on screen information as referenced in the Owners Manual, either.  I’m curious as to whether this is a feature that was supposed to be provisioned on the hybrid models by the dealer at delivery, but was missed?

Perhaps  Ford may install these missing Power Flow and Power  Guage via a future OTA updates.

[silvrsvt]

6 hours ago, DeluxeStang said:

The hybrids are a little loud during cold startup, but most cars are fairly loud during cold startups. I highly doubt it's the throttle bodies getting stuck open, they would have discovered something like that in testing, and in the 15 years or so that the 2.5 has been on the market. 

 

I never noticed my Fusion Hybrid being excessively loud during start up. I know that the direct injection engines like the Ecoboost can be "loud" due to the fuel pumps

[Gurgeh]

1 hour ago, smsfordman said:

Perhaps  Ford may install these missing Power Flow and Power  Guage via a future OTA updates.

Maybe. But I'm starting to think that for the three (what Lincoln characterizes as "glanceable") app positions to the right of the screen they are being purposefully selective in what can be slotted in those positions. An energy flow gauge might be something one looks at for a bit, not just glances at for fairly static information (like time, weather, song being played, current average mpg and whether the vehicle is in electric drive mode or not). If that's the case, I think they are being a bit overly-protective of the driver's safety, but I do get it.

[Rick73]

9 hours ago, DeluxeStang said:

The hybrids are a little loud during cold startup, but most cars are fairly loud during cold startups. I highly doubt it's the throttle bodies getting stuck open, they would have discovered something like that in testing, and in the 15 years or so that the 2.5 has been on the market. 

Guys on thread implied it was a flawed or defective part due to poor manufacturing.  Whether it was correct or not I have no idea, but if they were correct, it would not affect every vehicle, or have been picked up in previous testing.  I think a lot of poor quality occurred during COVID so I suppose it’s possible.

[Retired Dealer]

Very interesting topic. I just took delivery of a 2024 Lincoln Nautilus Hybrid. 
Can anyone tell me at what speed the gas engine engages? 
This is an amazing vehicle. My last vehicle was a 2013 Lincoln MKX. What a difference!

Fantastic job done on the design as well as attention to detail in regards to the fit and finish. 

[smsfordman]

11 hours ago, Gurgeh said:

Maybe. But I'm starting to think that for the three (what Lincoln characterizes as "glanceable") app positions to the right of the screen they are being purposefully selective in what can be slotted in those positions. An energy flow gauge might be something one looks at for a bit, not just glances at for fairly static information (like time, weather, song being played, current average mpg and whether the vehicle is in electric drive mode or not). If that's the case, I think they are being a bit overly-protective of the driver's safety, but I do get it.

The power guages do not necessarly need to be on th e right side screen . Then can be projected on the center screen or the drivers side screen in front of the steering wheel. This is where the power flow guage is located on Escape hybrids.

[Gurgeh]

10 hours ago, Retired Dealer said:

Very interesting topic. I just took delivery of a 2024 Lincoln Nautilus Hybrid. 
Can anyone tell me at what speed the gas engine engages? 
This is an amazing vehicle. My last vehicle was a 2013 Lincoln MKX. What a difference!

Fantastic job done on the design as well as attention to detail in regards to the fit and finish. 

The gas engine engages pretty much as soon as you start seriously accelerating. I typically can't even hear it turn on; I just notice that the "Electric Driving" on the MPG widget goes off. One nice thing is how the moving in and out of electric driving obviates the need for a start/stop system. It is just so seamless and smooth.

 

I agree on the design, and the fit and finish is the best in any car I've ever owned. Now, if they could just stamp those bugs out of the new infotainment system...