EV Super Duty with Coyote range extender under consideration

[akirby]

https://tfltruck.com/2024/09/video-ford-super-duty-ev-with-a-5-0l-gas-v8-range-extender-may-be-coming-we-have-insider-details/?fbclid=IwZXh0bgNhZW0CMTEAAR0vcZJYUqU4HccQD55aC-98m5zoXBYofzvtXxtRYDYUGS9lc2fX-yNYYos_aem_zoNoWj7D_DBTLotknasXNA

[Texasota]

Quote

Our insider source says that Ford is currently struggling with having enough energy while pulling a maximum load up a long grade with such a setup. This issue may be resolved by adding a special tow/haul mode that kick the generator on while the battery still has 30% or 40% battery while towing. If the generator is kicked on early enough – it may offer the battery enough backup to finish climbing the mountain with sufficient power.

That has been my concern all along with the idea of an EREV in general. Once the battery is depleted it may be an unpleasant driving experience trying to maintain speed under heavy load and Super Duty's are supposed to shine when performing under heavy load. You will likely be trading range anxiety for an entirely different kind of anxiety. I think any EREV (including the RamCharger) is going to struggle with this problem. A problem that a HEV or a PHEV does not have.

Edited September 18, 2024 by Texasota

[akirby]

15 minutes ago, Texasota said:

That has been my concern all along with the idea of an EREV in general. Once the battery is depleted it may be an unpleasant driving experience trying to maintain speed under heavy load and Super Duty's are supposed to shine when performing under heavy load. You will likely be trading range anxiety for an entirely different kind of anxiety. I think any EREV (including the RamCharger) is going to struggle with this problem. A problem that a HEV or a PHEV does not have.

Thats not how they’re supposed to work though.  The extender should just replenish part of the battery charge while driving which slows the battery depletion.  It’s not designed to provide 100% propulsion with a max load.

[Texasota]

9 minutes ago, akirby said:

Thats not how they’re supposed to work though.  The extender should just replenish part of the battery charge while driving which slows the battery depletion.  It’s not designed to provide 100% propulsion with a max load.

I get what you are saying but at some point during that supposedly 700 mile range the battery and generator are not going to be able to keep up. It’s a very inefficient design once the generator kicks in (too many energy conversions).

[fordmantpw]

20 minutes ago, Texasota said:

I get what you are saying but at some point during that supposedly 700 mile range the battery and generator are not going to be able to keep up. It’s a very inefficient design once the generator kicks in (too many energy conversions).

 

Legitimate concern based on the article:

 

Quote

Our insider source says that Ford is currently struggling with having enough energy while pulling a maximum load up a long grade with such a setup. This issue may be resolved by adding a special tow/haul mode that kick the generator on while the battery still has 30% or 40% battery while towing. If the generator is kicked on early enough – it may offer the battery enough backup to finish climbing the mountain with sufficient power.

 

The system could easily calculate the energy you are using, and determine the available capacity to keep on hand.  So, say, keep a minimum of 25 miles of battery capacity, which could provide enough energy along with the ICE to climb any long grade in the US.  That 25 miles of capacity could be 10kWh or it may be 50kWh, depending on the size of the load you are towing.  (I'm throwing numbers around here as a concept, not actual values)

 

There could also be a way for the driver to select extra capacity if they want to keep some spare range on hand.  For instance, if they are going to be boondocking in their RV and want the battery charged fully when they reach their destination so they can use the truck for power.

 

I'm hoping they make this a reality because this is exactly what I want in my next Super Duty!

[akirby]

2 hours ago, Texasota said:

I get what you are saying but at some point during that supposedly 700 mile range the battery and generator are not going to be able to keep up. It’s a very inefficient design once the generator kicks in (too many energy conversions).

It’s inefficient to convert gasoline to electricity but it’s the only option here.  Max range with a max load up a mountain might be a lot less than expected but it should work under most other circumstances.

[Rick73]

I don’t see a big problem for most drivers under most conditions.  The power issue some are concerned about only applies after battery bank is essentially drained.  That can be prevented easily.

 

We also know rough specs from RAM that 3.6L Pentastar-driven generator can produce up to 130 kW of charge, equivalent to 174 HP.  Obviously only part of that reaches driven wheels, but it’s a high percentage.  Since Ford 5.0L Coyote V8  is quite a bit more powerful than Pentastar V6, it should make at least 180 kW of maximum charge, or 240 HP equivalent.  I’d guess roughly 200 HP should reach driven wheels.

 

If trying to replace a 400 HP diesel (keeping in mind not all HP with diesel reach wheels either) and over half of that electricity can come from engine/generator, then battery bank only needs to make up difference.  Even if going over Ike Gauntlet tfltruck guys use for extreme towing tests, it normally only takes 9 to 12 or so minutes.  Any battery capacity that can provide 120 miles of range as empty BEV should be able to handle this worst-case scenario of additional 200 kW or less for 9~12 minutes.  Then you recharge faster on way down from tunnel with regeneration.

 

If that’s not enough, driver can slow down some.  That will reduce power requirement and allow generator to produce a higher percentage of need, thereby draining battery slower.

 

Additionally, Ford could bring back 5.4/5.8L taller-deck block and make an even more powerful Coyote.  As I suggested in two other threads over last year, Ford could increase displacement perhaps as high as 6 Liters, making 200 kW of charging a possibility.  Whether manufacturing of such an engine is physically and or economically feasible I don’t know, but I wouldn’t rule out an EREV Super Duty based on TFLT comments.  Technical possibilities are much greater than those two guys imagine.

[SoonerLS]

 

The Coyote part doesn’t really make much sense to me, especially when they have the 6.8 available. The Coyote is a big package and it’s more complex than the baby Godzilla, plus the 6.8 is already in the Super Duties, so you wouldn’t be adding more logistical complexity. Also, the 5.0 doesn’t really come alive until it’s up in the revs, and you’d think you’d want something that’s happier at lower revs, like a big ol’ pushrod V8.

[Rick73]

6 hours ago, SoonerLS said:

The Coyote part doesn’t really make much sense to me, especially when they have the 6.8 available. The Coyote is a big package and it’s more complex than the baby Godzilla, plus the 6.8 is already in the Super Duties, so you wouldn’t be adding more logistical complexity. Also, the 5.0 doesn’t really come alive until it’s up in the revs, and you’d think you’d want something that’s happier at lower revs, like a big ol’ pushrod V8.

I expect the biggest advantage to a DOHC Coyote V8 is that it can be easily modified to Atkinson cycle for improved fuel economy.  Perhaps compression ratio would be increased from 12 to about 14 which is not uncommon for Atkinson engines.  You’re correct that it would likely be more expensive, but for powering a generator, I’d expect an Atkinson engine like RAM specs show for 3.6L Pentastar V6 in their EREV.  A longer stroke also benefits Atkinson cycle, which is why a 5.8 ~ 6.0L Coyote-based V8 would be cool to see.

[fordmantpw]

The V8 doesn't need a wide powerband either.  It'll run at a fixed RPM where it's most efficient.

[akirby]

7 hours ago, SoonerLS said:

The Coyote part doesn’t really make much sense to me, especially when they have the 6.8 available. The Coyote is a big package and it’s more complex than the baby Godzilla, plus the 6.8 is already in the Super Duties, so you wouldn’t be adding more logistical complexity. Also, the 5.0 doesn’t really come alive until it’s up in the revs, and you’d think you’d want something that’s happier at lower revs, like a big ol’ pushrod V8.

 

But it’s not connected to the drivetrain so RPM is irrelevant to driveability.  It can run at whatever RPM is needed or is most efficient.

[Flying68]

1 hour ago, akirby said:

 

But it’s not connected to the drivetrain so RPM is irrelevant to driveability.  It can run at whatever RPM is needed or is most efficient.

This.  There are actually 2 ways to run a generator, the first and most desirable is at peak efficiency.  That would be finding the point in the RPM vs Hp band that has the lowest specific fuel consumption.  Ideally this is where the bulk of the recharge would be, likely equivalent to a lower RPM with a lot of vacuum.  The second would be to run at peak power output.  This would be used to supplement the battery (likely bypassing the recharge) and supply maximum kW to the motors directly.  This is though would require a generator that can operate efficiently at that peak power input rpm and has the capacity to efficiently generate power there.

[fordmantpw]

1 hour ago, Flying68 said:

This.  There are actually 2 ways to run a generator, the first and most desirable is at peak efficiency.  That would be finding the point in the RPM vs Hp band that has the lowest specific fuel consumption.  Ideally this is where the bulk of the recharge would be, likely equivalent to a lower RPM with a lot of vacuum.  The second would be to run at peak power output.  This would be used to supplement the battery (likely bypassing the recharge) and supply maximum kW to the motors directly.  This is though would require a generator that can operate efficiently at that peak power input rpm and has the capacity to efficiently generate power there.

 

Good point.  Run at the most efficient for normal charging, crank up to max output when it's needed for climbing hills.

[DeluxeStang]

Correct me if I'm wrong chaps, but with these range extender setups, the engine is never powering the vehicle itself. Power and acceleration isn't impacted by the engine directly, nor is any of the strain of moving the vehicle down the road placed on the engine. So with that in mind, isn't making the range extender a 5.0 a bit overkill? If the engine isn't doing anything other than recharging the batteries, why does it need to be this great big thumping V8. Wouldn't using a smaller, cheaper, and more fuel efficient engine make more sense for this application?

[akirby]

8 minutes ago, DeluxeStang said:

Correct me if I'm wrong chaps, but with these range extender setups, the engine is never powering the vehicle itself. Power and acceleration isn't impacted by the engine directly, nor is any of the strain of moving the vehicle down the road placed on the engine. So with that in mind, isn't making the range extender a 5.0 a bit overkill? If the engine isn't doing anything other than recharging the batteries, why does it need to be this great big thumping V8. Wouldn't using a smaller, cheaper, and more fuel efficient engine make more sense for this application?

Apparently it needs the extra hp to keep up with the battery depletion.

[SoonerLS]

3 hours ago, akirby said:

 

But it’s not connected to the drivetrain so RPM is irrelevant to driveability.  It can run at whatever RPM is needed or is most efficient.

I’m not talking about drivability, I’m just thinking that an engine that’s designed to work higher in the revs is going to work more efficiently at a higher RPM than one that’s designed to earn its pay lower in the revs. 

[Rick73]

1 hour ago, SoonerLS said:

I’m not talking about drivability, I’m just thinking that an engine that’s designed to work higher in the revs is going to work more efficiently at a higher RPM than one that’s designed to earn its pay lower in the revs. 

Just because a modern engine can spin to high RPMs to make a lot of power doesn’t mean it’s not most efficient at much lower RPM.  Actually, in reality and for practical purposes a modern engine is most efficient over a large range of RPM and Power.  It’s not just a single point on BSFC map.  Obviously there is a theoretical highest point of efficiency somewhere, but incremental improvement over wide range surrounding that point in fuel economy is not worth discussing in practice (real world applications).  I can’t find map for Coyote, but a Toyota 2.5L half the size can serve as example.  It peaks at around 200 HP (150 kW) at 6500 RPM, yet best efficiency of 220 grams of fuel per kW-hr can be from under 2,000 to over 3,000 RPM, and power from roughly 20 to 75 kW.  I expect the Coyote in F-150 tune is very similar to this Toyota except +/- 400 peak HP instead of 200.

 

Doing a little reverse engineering for perspective, I can estimate my 1-ton van requires about 70 HP on average at moderate Interstate speeds, and when towing a mid-size camper can jump up to as high as 120 HP on average.  Going uphill makes these numbers much higher, but for an EREV the extra short-term power would come from batteries.  For example, a mile-long hill that takes a minute at 60 MPH shouldn’t be an issue for a large battery.  It would represent a small percentage of battery capacity.

[Texasota]

36 minutes ago, Rick73 said:

Just because a modern engine can Going uphill makes these numbers much higher, but for an EREV the extra short-term power would come from batteries.  For example, a mile-long hill that takes a minute at 60 MPH shouldn’t be an issue for a large battery.  It would represent a small percentage of battery capacity.

But, from the article that is the problem that Ford is struggling with for this Super Duty EREV.

[mackinaw]

Let's see what Stellantis does.  The Ram EREV will beat the F-series EREV to market, so Stellantis engineers are struggling with the same problem, and have probably already come up with a solution.  

[Rick73]

1 hour ago, Texasota said:

But, from the article that is the problem that Ford is struggling with for this Super Duty EREV.

I think what we are reading is mostly rumors and hearsay, so I wouldn’t get bogged down in details we don’t know at this point, or accuracy of their speculation.  I was simply trying to show that concept could be made to work for many buyers.

 

We know that pickup trucks can easily triple energy consumption per mile when towing heavy and large trailers close to their max tow rating, whether gas, hybrid, or electric.  IMO the speculated 120 miles of range when empty could turn to 40~50 miles when towing heavy.  My guess is that many buyers who tow most of the time will stick with conventional powertrains for now.  On the other hand, buyers who only occasionally tow and drive empty much of the time may love an EREV.  It’s hard to say since we don’t even know the price premium.

 

When I was in school back in the dark ages of electrification, the mechanical engineering department built two hybrids with same EREV powertrain concept, and they both had similar issues.  One was a city bus with a diesel generator, and it performed well given available technology of the time.  What helped a lot was that average power consumption was very low due to low city speeds and time the bus was stopped.  The other vehicle, a small passenger car, was not as competitive because of low powertrain efficiency compared to conventional cars.

 

I have mentioned this before, and this thread may be good place to repeat.  Perhaps Ford can engineer a truck-specific transmission using the same concept as Honda’s two-motor design.  It’s essentially the same concept we have been discussing for EREV, except the generator and drive motor can be connected directly by a clutch.  As I understand it, the latest Honda system operates just like an EV at low speeds and once up to cruising speed, the clutch connects engine to wheels (through gear reduction of course).

[Captainp4]

19 hours ago, SoonerLS said:

 

The Coyote part doesn’t really make much sense to me, especially when they have the 6.8 available. The Coyote is a big package and it’s more complex than the baby Godzilla, plus the 6.8 is already in the Super Duties, so you wouldn’t be adding more logistical complexity. Also, the 5.0 doesn’t really come alive until it’s up in the revs, and you’d think you’d want something that’s happier at lower revs, like a big ol’ pushrod V8.

Came here to say this as well, I see it's been discussed and I'm not really convinced, but I never did finish my engineering degree so...

Seems to me adding the cost and complexity and relatively low tq numbers of a DOHC v8 doesn't really make sense in a generator application. Smaller displacement godzilla or even one of the smaller ecoboost v6s with big tq numbers make more sense in my head, though that would add even more complexity and fuel consumption under heavy load with a turbo is tricky.

Honestly don't like these EREV things, seems like a lot of different crap to go wrong. It's a good stop gap measure, but I personally think they'll end up obsolete sooner than later as battery tech evolves. A superduty one does fit my personal use case right now though. 99% <100 miles a day towing ~10k with a couple big road trips towing several hundred miles per year.

[Texasota]

The number of energy conversions in EREVs is significant once the generator kicks in and each energy conversion step results in an efficiency loss. Here is what I see happening once that generator starts running:

 

1. Gasoline (chemical) energy converted to mechanical energy.
   
   The gasoline is burned in the EREV's ICE to create mechanical (rotational) energy. Probably the biggest energy loss occurs here. Note that all ICE vehicles encounter this loss.
    
2. Mechanical energy converted to DC electrical energy
   
   The crankshaft of the ICE is driving a generator to produce DC electrical energy.
    
3. DC electrical energy converted to chemical energy
   
   The DC output of the generator is sent to the EREV's battery and converted to chemical energy.
    
4. Chemical energy converted to DC electrical energy
   
   The EREV's battery converts the stored chemical energy back to DC electrical energy.
    
5. DC electrical energy converted to mechanical energy
   
   The DC electrical energy released by the battery is converted to mechanical (rotational) energy via one or more electrical motors.

Note: The EREV may be designed to skip steps 3 and 4 if the generator's DC output bypasses the battery and is directed straight to the electric motors. I assume this is how a Diesel/Electric locomotive works. But, some portion of the output probably still must go to the Li-ION battery and a 12-volt battery.

[akirby]

Since when is a coyote v8 relatively low torque?

[Biker16]

13 hours ago, akirby said:

Apparently it needs the extra hp to keep up with the battery depletion.

 

I don't think it needs that much power. Honestly, a small V6 or large I4 should be enough. 200-220hp should be enough. 

 

The perfect engine would be a small gas turbine. 

 

I think people are overestimating the usefulness of large motors in this scenario. The majority of the time this thing shouldnt be running. Which creates its own unique challenges.

[Biker16]

3 hours ago, Texasota said:

The number of energy conversions in EREVs is significant once the generator kicks in and each energy conversion step results in an efficiency loss. Here is what I see happening once that generator starts running:

 

1. Gasoline (chemical) energy converted to mechanical energy.
   
   The gasoline is burned in the EREV's ICE to create mechanical (rotational) energy. Probably the biggest energy loss occurs here. Note that all ICE vehicles encounter this loss.
    
2. Mechanical energy converted to DC electrical energy
   
   The crankshaft of the ICE is driving a generator to produce DC electrical energy.
    
3. DC electrical energy converted to chemical energy
   
   The DC output of the generator is sent to the EREV's battery and converted to chemical energy.
    
4. Chemical energy converted to DC electrical energy
   
   The EREV's battery converts the stored chemical energy back to DC electrical energy.
    
5. DC electrical energy converted to mechanical energy
   
   The DC electrical energy released by the battery is converted to mechanical (rotational) energy via one or more electrical motors.

Note: The EREV may be designed to skip steps 3 and 4 if the generator's DC output bypasses the battery and is directed straight to the electric motors. I assume this is how a Diesel/Electric locomotive works. But, some portion of the output probably still must go to the Li-ION battery and a 12-volt battery.

 

It may make sense to have the generator output high voltage AC 3 phase directly into the drive system, since the E motors runs on 3 phase AC. The range extender would use the motor's inverter to convert the AC into DC to charge the battery. 

 

AC generators are more efficent, and sending power directly to the wheels bypassing the battery reduces wear on the battery, high wattage charging.

 

This also allows the battery and RE to work in parallel, reducing peak energy output from the battery pack.

 

This setup would make the range extender plug and play with pure BEV trucks.