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Comment by ageitgey | Hacker News Reader

PHEV sounds like a great idea, but you end up driving around in a car with the cost, weight and complexity of two cars worth of engines just in case you occasionally need the second engine. Also, the design of the car is limited by having to accommodate the needs of the combustion engine so you lose out on a lot of your interior space. One of the nicest parts of EVs is that you can reclaim a lot of internal space for passengers since the engine is a lot simpler.

As electric cars keep getting cheaper and the ubiquity of rapid charging keeps improving, I think for a lot of people the PHEV concept won't work out as well as it sounds. It will be just as easy to rapid charge a mid-range EV for long trips and you get the benefit of all your day-to-day driving being nicer as well.

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A PHEV isn’t as complicated as ICE and BEV together nor is it as heavy or as expensive.

If anything once we can make carbon neutral synthetic fuel out of renewables what would be the purpose of BEV environmentally?

Exactly. I’m sure people made the same misguided argument about diesel electric train engines.

For one thing, fuel burning vehicles make exhaust that is unnecessary. But the main reason is they are vastly more complicated and expensive to design, build, maintain than battery vehicles. bev have something like 90% fewer parts.

> For one thing, fuel burning vehicles make exhaust that is unnecessary. But the main reason is they are vastly more complicated and expensive to design, build, maintain than battery vehicles. bev have something like 90% fewer parts.

People keep saying this but is this true? Modern ICE is pretty well understood. We’re not taking about a Honda beater from the 80s. Not to mention in the context of a PHEV you still wouldn't have exhaust for most trips anyway.

Modern ICE have been refined for over 100 years and have improved enormously. But there is just a lot more involved in making them move than electric engines.

That's not to say EVs aren't complex or hard to build. There are a lot of parts inside the battery pack. But they aren't moving parts and they don't need the same kind of regular maintenance. Electric cars don't have oil to change and they almost never need brakes replaced because of regen. They don't have O2 sensors that fail, they don't have spark plugs to change, they don't have timing belts to replace, etc. If you look at a list of the top 10 most frequent car repairs, maybe 9 of them can't happen on an electric car. It is just a simpler system of moving parts. The complexity is in a different place.

The problem with PHEV is you have the different types of complexity of both systems combined just in an effort to boost range.

> are vastly more complicated and expensive to design, build, maintain than battery vehicles.

True, ICE car are more complicated but its pretty clear that build and maintain is cheaper than BEV. ICE cars are half the price of EVs. Maintenance of good Japanese cars is cheap, I spend like $30/yr on oil changes.

• You still have NOx emissions, no matter what fuel you burn.

• PHEVs have (pretty much by definition) smaller batteries, so they discharge/cycle more of their capacity, wearing down batteries quicker. They're also less convenient, because they have to be plugged in more often and charge slower (if you don't plug them in daily, they're just overcomplicated ICE cars).

• A pure electric drive train is pretty energy-efficient (80%+ Well-to-Wheel efficiency). Combustion engines are only about 35% efficient (and it won't get better: there's no room to use the heat, and you can't avoid generating heat in a combustion engine). It's already bad even if you have perfectly efficient fuel synthesis. We're not near having too much electricity to waste.

• There's still an engine and a gearbox to maintain. These are mechanically much more complex and inherently more fragile than an EV power train.

• Most PHEVs on the market have weaker/laggier performance than BEVs due to having a smaller battery that can't deliver high peak power, and having only one electric motor due to sharing a power train with ICE.

Modern fast-charging BEVs already work great. They have effectively infinite range if you charge 20 minutes per 2-3 hours of driving. That's entirely within reason, and only about 10% slower than pee-in-a-bottle road trips.

BEVs are about 80% efficient in Wall-to-Wheel measures. What the Well-to-Wheel measure is depends on the efficiency of the power generation and losses in distribution. If it’s powered by natural gas, that generation itself is only around 40% efficient.

Wind and solar power are taking over in a lot of states. My local power company claims to be 85% wind (but only in newspapers, when I look for evidence I can't find proof)

I think it's worth pointing out that uncharged PHEVs still work like hybrids. They benefit from regen braking and can optimize when to most optimally use stored energy.

I do wish more folks with PHEVs would ensure they're plugged in as much as possible, but I'm still of the position that they have a reasonable usecase while the world transitions.

Regen is not an energy source. An unplugged PHEV takes all of its energy from gasoline, so it's just an ICE car with implementation details.

Regen improves overall efficiency by 3%-10%. It has a relatively small effect even in BEVs. Majority of the energy is lost to rolling resistance and drag (otherwise you could just turn your engine off and coast to your destination…), so there isn't that much to capture. I'm not sure if it even cancels out the extra weight and inefficiency of PHEVs having two power trains. It makes less of a difference than variability between ICE models, so you could be better off driving a smaller pure ICE car.

> so it's just an ICE car with implementation details

Is that how you would also describe a non-plugin hybrid?

> PHEVs have (pretty much by definition) smaller batteries, so they discharge/cycle more of their capacity, wearing down batteries quicker. They're also less convenient, because they have to be plugged in more often and charge slower (if you don't plug them in daily, they're just overcomplicated ICE cars).

If you don't plug them in daily, they're very fuel efficient ICE cars, with nice acceleration from a stop, and the opportunity to get free charging at some locations, rockstar parking at others (sometimes for a small fee), and maybe carpool stickers.

> • A pure electric drive train is pretty energy-efficient (80%+ Well-to-Wheel efficiency). Combustion engines are only about 35% efficient (and it won't get better: there's no room to use the heat, and you can't avoid generating heat in a combustion engine). It's already bad even if you have perfectly efficient fuel synthesis. We're not near having too much electricity to waste.

You're right about efficiency, but Texas often has overnight periods with too much electricity, and the California solar peak is close too (to the point where time of use rates have changed and there's an off peak price during the middle of the day). That's likely not enough to make fuel synthesis viable, of course.

> • There's still an engine and a gearbox to maintain. These are mechanically much more complex and inherently more fragile than an EV power train.

> • Most PHEVs on the market have weaker/laggier performance than BEVs due to having a smaller battery that can't deliver high peak power, and having only one electric motor due to sharing a power train with ICE.

Most PHEVs (and most HEVs) on the market are using a ICE + two electric motor + gears power system. Early Honda hybrids had a different system, but afaik, everyone else adopted the system that Toyota pioneered, sometimes called an e-CVT. There's no gear selection mechanism and it's relatively simple. (Apart from manufacturing errors, but if Ford can make a hybrid transmission that fails early, they can make BEV gearing that fails early too; hopefully my replacement transmission outlasts the rest of the components)

My PHEV has a two year maintenance interval for the engine, and sure, that's more than an engineless car, but modern engine maintenance is fairly painless. Change the oil when the minder tells you, make sure the drive belt or chain gets changed on times. Spark plugs when they need them. Fiddle with the emissions control when the light turns on.

Performance seems more than adequate, I can spin the tires from a stop, and it goes faster when I push the pedal down more. The only time there's significant lag in response is if you put it in EV only mode and try to get up to free flowing freeway speeds to merge. But, that's a silly thing to do; the battery evaporates at freeway speeds, and the gas engine gets best mileage at freeway speeds, using the whole car will get you the best results.

Poor interior space is a real issue, especially in mine (Ford didn't take the time to find a good place for the batteries, they just shoehorned them into an already small cargo area)

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