EREV - A Horsepower Math Problem?

[chriserx]

Here it is with the doors open. The blue cylinder is the important part, a very large and heavy alternator. For scale, look at the battery.

From what I have read I get the impression that the REV is 30kW , and even that is a big ask for a gasoline Pentastar V6. I would question the longevity of that system, although I'm a diesel guy so I suppose I am biased.

Based on my truck's power draw of ~54 kw at 80 mph, and the fact that trucks will occasionally tow stuff and be required to go up hill, I'd say the absolute minimum Ford could get away with here is 75 kw, but most likely to be rated for -100 kw. It's not a particularly big ask to fit a 5.2L engine into a vehicle that can already fit them. As far as the alternator goes, a long cylindrical one is probably the more efficient design, but it's not the only one. Even if they kept that design, they could face it toward the firewall and under the cab. Without the need for a transmission or drive axles there are actually quite a few options. If they went with a Mazda style rotary engine they could put it literally anywhere.

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[Lomilar]

All of this just sounds terrible. Whether it’s a V6 Pentastar, or a 2.7 Turbo, who wants this? Those are power plants that already power full sized pickup trucks, and require all of the regular maintenance, expenses, inconveniences of an ICE vehicle. Then throw in the battery and all of its potential issues. Not to mention that if going the turbo route, that further increases complexity and failure points.

I still don’t think this moves the needle for the traditional truck buyer. A lot of old school guys will still not like that they can’t fix it themselves if something goes wrong, and new gen will want pure EV. The price is likely to be equal or more than pure EV with the extra hardware.

I love reading the technical aspects of this experiment, but the more I read, the less I believe you’re average Joe is going to sink their hard owned money into this.

I think everyone is way overestimating what kind of engine is required to make this work. You want an Atkinson cycle with zero turbos, something like the Duratec 4 or 6 cyl. You want an engine optimized for exactly one RPM, which it pretty much lives at. And you want somewhere between 200-320 peak hp (depending on how much battery you have) to support towing + grade.

All this means you can really optimize for durability and longevity, which you will have to, given how much the engine will be sitting.

 

[VAF84]

I think everyone is way overestimating what kind of engine is required to make this work. You want an Atkinson cycle with zero turbos, something like the Duratec 4 or 6 cyl. You want an engine optimized for exactly one RPM, which it pretty much lives at. And you want somewhere between 200-320 peak hp (depending on how much battery you have) to support towing + grade.

All this means you can really optimize for durability and longevity, which you will have to, given how much the engine will be sitting.

I'd like to think so (overestimating). I'm giving the Ford engineers some benefit of the doubt, since I doubt they'd create a replacement product that sounds objectively worse in most ways than what is being replaced. That is, unless this is being driven by exec's who don't have a lot of hands on technical expertise, haven't spent considerable time as truck owners, and haven't experience living with an EV.

 

[Lytning]

All of this just sounds terrible. Whether it’s a V6 Pentastar, or a 2.7 Turbo, who wants this? Those are power plants that already power full sized pickup trucks, and require all of the regular maintenance, expenses, inconveniences of an ICE vehicle. Then throw in the battery and all of its potential issues. Not to mention that if going the turbo route, that further increases complexity and failure points.

I still don’t think this moves the needle for the traditional truck buyer. A lot of old school guys will still not like that they can’t fix it themselves if something goes wrong, and new gen will want pure EV. The price is likely to be equal or more than pure EV with the extra hardware.

I love reading the technical aspects of this experiment, but the more I read, the less I believe you’re average Joe is going to sink their hard owned money into this.

Consider the Recalls, CSP's and TSB's of @Ford Motor Company's ICE F-150's. Consider the Recalls, CSP's and TSB's of the BEV components (i.e., non-overlap with ICE) of the F-150 Lightnings. Add them together. Then, throw in a few extra for the additional complexity of combining both ICE and BEV systems for the first time in a new vehicle.

How many existing F-150 ICE or Lightning owners are going to spend even more money for an even less reliable truck than they have now?

 

[PJnc284]

Consider the Recalls, CSP's and TSB's of @Ford Motor Company's ICE F-150's. Consider the Recalls, CSP's and TSB's of the BEV components (i.e., non-overlap with ICE) of the F-150 Lightnings. Add them together. Then, throw in a few extra for the additional complexity of combining both ICE and BEV systems for the first time in a new vehicle.

How many existing F-150 ICE or Lightning owners are going to spend even more money for an even less reliable truck than they have now?

We should have a recall drinking game when/if this all comes to fruition. Not sure i can afford or even handle that much alcohol.

 

[grottomatic]

I think everyone is way overestimating what kind of engine is required to make this work. You want an Atkinson cycle with zero turbos, something like the Duratec 4 or 6 cyl. You want an engine optimized for exactly one RPM, which it pretty much lives at. And you want somewhere between 200-320 peak hp (depending on how much battery you have) to support towing + grade.

All this means you can really optimize for durability and longevity, which you will have to, given how much the engine will be sitting.

Maybe. I think the hybrid Atkinson cycle engines are going to have a tough time supplying the truck in edge case conditions which is kind of why ford is in the situation it is in- the Lightning “failed” in fords eyes due to range collapse towing and in the cold.

if the go with a smallish hybrid engine then you will have a situation where you will be in a derated condition when towing grades. Edge case but important to theoretical buyers. I think if ford wants this to be a true towing machine then they have to have an engine able to supply the vast majority of power at peak demand.

if they actually build it- the genset will have to be substantial and will likely have multiple modes - standard output and a max output. To supply max output it may be better for a tuned turbo generator where it can produce massive power for heavy loads for short periods and standard output, likely somewhere out of boost, to just recharge the battery- out of boost. 2.7 would be perfect for this but packaging and price would be a nightmare. And at that point why not just build a traditional hybrid or small battery PHEV 2.7 that could have 40 miles or all electric range?

I don’t know if the economics work out but would be happily surprised to find out otherwise

 

[Lomilar]

Maybe. I think the hybrid Atkinson cycle engines are going to have a tough time supplying the truck in edge case conditions which is kind of why ford is in the situation it is in- the Lightning “failed” in fords eyes due to range collapse towing and in the cold.

if the go with a smallish hybrid engine then you will have a situation where you will be in a derated condition when towing grades. Edge case but important to theoretical buyers. I think if ford wants this to be a true towing machine then they have to have an engine able to supply the vast majority of power at peak demand.

if they actually build it- the genset will have to be substantial and will likely have multiple modes - standard output and a max output. To supply max output it may be better for a tuned turbo generator where it can produce massive power for heavy loads for short periods and standard output, likely somewhere out of boost, to just recharge the battery- out of boost. 2.7 would be perfect for this but packaging and price would be a nightmare. And at that point why not just build a traditional hybrid or small battery PHEV 2.7 that could have 40 miles or all electric range?

I don’t know if the economics work out but would be happily surprised to find out otherwise

I could see a 4cyl ecoboost to achieve better peak horsepower given a smaller footprint. That occurred to me after I wrote this.

Max tow isn't ever going to be a need for 320hp supplied forever though. You can also, in extreme edge cases (start at the bottom of a mountain with zero battery) pull over and generate, go slower than 80mph, or like... start it up and let it recharge itself.

 

[grottomatic]

Max tow isn't ever going to be a need for 320hp supplied forever though. You can also, in extreme edge cases (start at the bottom of a mountain with zero battery) pull over and generate, go slower than 80mph, or like... start it up and let it recharge itself.

I think that would be reasonable but YouTube testers will exactly seek out edge cases and make the truck look bad and will kill sales off the bat. Hoovies garage did a lot of damage making videos showing Lightning when it first came out towing in the cold. Imagine if TFL had to stop and sit and charge prior to doing the Ike gauntlet - not a good look.

I don’t agree with it but I don’t think ford is going to build another electric truck that isn’t everything to everyone this time around. They werent happy with having the number 1 electric truck with the lightning. If they can’t build something that has no compromise at edge cases they wont build it at all.

 

[Lomilar]

I think that would be reasonable but YouTube testers will exactly seek out edge cases and make the truck look bad and will kill sales off the bat. Hoovies garage did a lot of damage making videos showing Lightning when it first came out towing in the cold. Imagine if TFL had to stop and sit and charge prior to doing the Ike gauntlet - not a good look.

I don’t agree with it but I don’t think ford is going to build another electric truck that isn’t everything to everyone this time around. They werent happy with having the number 1 electric truck with the lightning. If they can’t build something that has no compromise at edge cases they wont build it at all.

"Here we are doing the Pike's Peak run having just finished an absolutely stellar overnight bender, having fully depleted our 55kwh battery powering a 7000 watt DJ setup for 12 hours straight... Towing a trailer carrying a Polestar One and a Mazda MX-30, so a totally normal Thursday morning. Let's see if the new 2028 Ford Lightning EREV can dissapoint us again."

 

[Newton]

Aha, I think I see where the confusion (or at least my confusion) comes from. Automakers/journalists have invented a new way to rate generators.

Power flows from the specifically designed 3.6-liter V6 to the on-board generator that makes 174-hp (130-kW). The driver can use the energy to recharge the battery when it’s depleted or to preserve it. The vehicle can use both the generator and the battery simultaneously for maximum power output, while software and drive modes help regulate the charging parameters that includes one for towing.

That parenthesis is doing a lot of work here. You cannot rate a generator by taking two thirds of the horsepower of the source engine. Even in an ideal world with no losses it doesn't work that way. The kW that a generator produces is entirely limited by the rating of the alternator. If you put a 500hp engine on a 20kW alternator you will get exactly the same power characteristics as if you attached it to a 40hp engine. In fact, generator manufacturers may use the same engine produce different ratings of generators simply by putting in a larger alternator (and tuning the engine differently).

Horsepower and torque are not the same thing, a lightweight high-horsepower engine attached to a generator will not be able to produce the same power as a lower horsepower, higher torque engine. This is why diesels are kings for large generators.

I'm not saying that the Ram Rev doesn't work, obviously it does, but I really do not think that it is a 130kW generator.

EVs are so much simpler.

 

[proprepper]

I've put 130k miles on my 2017 volt. It's a weird arrangement erev kind of car. It's been a super car.

It does have a thing called mountain mode? that ensures you have enough high voltage battery to provide full power for going up extended grades. You engage it before you encounter a steep grade mountain pass.

Maybe the truck will be similar setup controls?

 

[chriserx]

Aha, I think I see where the confusion (or at least my confusion) comes from. Automakers/journalists have invented a new way to rate generators.



That parenthesis is doing a lot of work here. You cannot rate a generator by taking two thirds of the horsepower of the source engine. Even in an ideal world with no losses it doesn't work that way. The kW that a generator produces is entirely limited by the rating of the alternator. If you put a 500hp engine on a 20kW alternator you will get exactly the same power characteristics as if you attached it to a 40hp engine. In fact, generator manufacturers may use the same engine produce different ratings of generators simply by putting in a larger alternator (and tuning the engine differently).

Horsepower and torque are not the same thing, a lightweight high-horsepower engine attached to a generator will not be able to produce the same power as a lower horsepower, higher torque engine. This is why diesels are kings for large generators.

I'm not saying that the Ram Rev doesn't work, obviously it does, but I really do not think that it is a 130kW generator.

EVs are so much simpler.

The parentheses is specifically converting horsepower to its metric equivalent.
I really think the main problem comes down to details, engine output are typically rated in both horsepower and kilowatts as well as thermal input. When talking about electricity, we typically only use kilowatts. When others write about engines and specifically engines used as a generator, they typically don't specify which metric they are referring to. Sure we could contextually infer which, but specifics would be nice.
Diesel's are also king due to a much greater thermal efficiency, naturally heavier duty components, etc. Other than cost and emissions, for a generator at least, they are superior to gas in every way I can think of.

 

[Wendy]

We should have a recall drinking game when/if this all comes to fruition. Not sure i can afford or even handle that much alcohol.

I think it’s hilarious you mention a drinking game and then immediately there is a White Claw Ad

maybe Brian AI is listening

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