EREV - A Horsepower Math Problem?

[ZeusDriver]

If i were Ford I'd just take the Ecoboost 3.5 truck and replace the 10 speed with whatever generator could use it's max power and let it power the current lightning drive train. Then stuff in as much battery as the chassis could carry and still have 1500 to 2000lb payload.
Tune the 3.5 for generator operation and let software give you what you need and when. Defeciencies in EPA range that happen due to battery size can be made up with fuel tank size.

I imagine that's not too far from what they will do. I doubt that they will use the engine in ecoboost configuration, because they can probably get better thermal efficiency by making it Atkinson cycle, and the engine can be simpler and lighter and cheaper and longer-lasting without the turbo and its controls.

Using the Lightning truck layout would probably work better to retain the two motors, the independent rear suspension, and the space for batteries (that not having a drive shaft allows). There may be enough room to put the engine above front electric motor, if the oil reservoir were mounted remotely.

I think they will limit the battery pack size to control cost. 150 mile EPA range at 2.2 m/kWh would be about 70 kWh pack, with the reduction in size from an SR lightning pack being about enough to offset the engine weight. The remaining 550 miles could come from a 25 gallon tank at 22 mpg. Making the pack smaller than 70 kWh would make it difficult to get the desired HP output from the motors.

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[ZeusDriver]

I don’t see why they don’t just make a big battery 2.7 ecoboost plugin hybrid. The 2.7 is a great engine, proven performer with high reliability that has been accepted by fleets-but needs more towing power, which they can get with electric on the driveline. I think they will ditch the current powerboost and work on a hybrid that can actually have the battery buffer to help with towing, and the battery only range to get you at least to work (30-40 kWh). The current powerboost has a tiny battery that is gone about half a second into towing a grade and then you get the poor economy of a 3.5 twin turbo on full blower.

I think the EREV is going to be too expensive and too heavy for the benefits without massive breakthroughs in battery weight and efficiency losses with genset operation. There will be massive warranty issues.

Without absolutely stunning performance out of the generator and DC bus (I don’t think you can get away without the ability for the generator to provide massive power directly to the motors in a towing situation) the solution doesn’t make a lot of sense for something early marketing tells us is going to “tow like a locomotive.”

I think the hitch with 30-40 kWh is getting adequate HP from the batteries. The SR Lightnings have a lower HP rating than the ERs because the battery pack is smaller. A parallel hybrid of your description would work well, but that is no what Jim Farley described.

The Ranger PHEV (in non US markets) has both very limited range and very limited performance in the electric-only mode. I think with the Ram EREV having the lead, that Ford will have to bring out something similar.

 

[PJnc284]

I think with the Ram EREV having the lead, that Ford will have to bring out something similar.

yup. There's a reason they said 700 miles to 1-up the Ram.

 

[ZeusDriver]

Lots of ways to find efficiency. For example, in the winter, running the generator because it generates waste heat that can warm the cabin and battery. Is that more efficient than using resistive heating?

The Chevy Volt did this. The efficiency (if measured in terms of equivalent kW input -- fuel value -- vs kW output of the heater) is much lower with the engine running. If the heating element is fully contained in the thing that you want to heat, then any electric heater is 100% efficient -- there is no "waste heat". An engine as a waste heat generator is not great, because a lot of heat goes out the exhaust, and a lot is radiated from the engine block, exhaust tubing and catalytic converter. Things improve if there is otherwise a need to run the generator, however.

In the volt, it appeared to me that comfort was the entire motive -- it was only in very cold weather that the engine would start up for that reason.

 

[mr.Magoo]

https://pmgenerators.com/dc-generators/

Probably end up with something similar to this. These guys have custom models that would offer 80kW and 400V and mounts directly to the flywheel.

 

[grottomatic]

I think the hitch with 30-40 kWh is getting adequate HP from the batteries. The SR Lightnings have a lower HP rating than the ERs because the battery pack is smaller. A parallel hybrid of your description would work well, but that is no what Jim Farley described.

The Ranger PHEV (in non US markets) has both very limited range and very limited performance in the electric-only mode. I think with the Ram EREV having the lead, that Ford will have to bring out something similar.

That’s interesting, didn’t know there was a Ranger PHEV. I was thinking they would transition to the 2.7 for the next gen powerboost model with a bigger battery and possibly better efficiency. With a larger electric motor (I think the current one is -45hp) there could be more torque fill to help with towing power and efficiency which is the weakness of the 2.7 (very little torque out of boost at lower rpm). With a bigger battery you could naturally get better range- at steady state unloaded.

At highway speeds a 100hp electric motor would be fine for ICE shutdown.

I’m assuming the EREV and any new power plant (hybrid/ice) will come with the updated truck in 2028 thus have a new frame and probably suspension.

I’m not as knowledgeable about this stuff as you though. Seems like the 3.5 may be overkill for a future power plant.

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