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Comment by ramesh31 | Hacker News Reader

>depending on your daily driving patterns

This is the key point. Modern highly efficient turbocharged 4 cylinder ICE vehicles can be equally or more efficient than a hybrid in the right circumstances as well. But the vast majority of driving is city streets <45mph, where ICE can't even come close to BEV.

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Well in the case of urban areas, outside of some select locations, the charging infra is just not there for BEVs. Even if there were good EV infra in urban areas, a compelling case could be made for improving and upgrading public transportation instead which is going to be more efficient than any personal vehicle - including BEVs.

A sidenote but unless public transport vehicles are electric, they won’t be better than battery electric vehicles. Typical diesel buses with typical occupancy rates have worse emissions per passenger mile then, say, a model three with a typical occupancy rate and grid emissions factor in US.

BEVs are fantastic, have SOME level of infrastructure literally everywhere with electricity (you literally can charge from a 120V outlet just fine), and we’ll need basically all vehicles to be battery electric to get to where we need to be.

It also is trivial to add EV charging infrastructure, which is another under appreciated aspect. It’s easier than installing a streetlight.

Most bus transit systems are in process to convert their fleet to EV. Most today don't run diesel, but CNG.

Personal vehicles also have a much larger carbon footprint in general (from manufacturing, maintenance, etc) aside from just emissions during operation of the vehicle.

Operations dominate the total carbon footprint of a gasoline fueled private vehicle. (And public transport buses as well.) so the comparison still is valid. To compete, buses need to also be electric (which is, to be fair!, super easy… electrifying all city buses is incredibly easy compared to electrifying all personal vehicles.)

There's been quite a few studies questioning the current focus on EVs with ranges of 400km and more. Largely because they are so heavy and are therefore not very energy efficient. The argument is that most peoples daily commute is less than 50km (in Europe), but they still by an overly heavy EV for the 5-10 times a year they go on longer trips. Instead a plugin hybrid could be much more efficient, because you can use it in EV mode for your commutes, but you can still use the car for long trips, without the significant weight (and corresponding inefficiency) increases of an EV. I suspect this is very much a function of the driving pattern, and I suspect in the mid-term future this will change with more efficient battery technology.

It will also change as the grid gets excess green energy.

But... are we pretending here that the ICE and gas & all the plumbing etc don't weigh anything? It's not like PHEV have zero additional dead weight.

A quick search says "Car engines can weigh up to 1,000 pounds" and "Tesla S has a massive battery weighing 1,200 lbs" - so, are your really saving that much weight with PHEVs?

Car engines can weigh up to 1000 pounds, but the standard weight is much lower. the VW group 1.4 turbo (probably one of the most common engines around) comes in at 230lb

I feel like this is a bit of a double standard.

If we're questioning "focus on range of 400km or more" then we're already looking at the high-end EVs. Sure there are ligther engines around, but so are lighter batteries, no? Heavy powerful ICEs sell because they're desirable, not because they're the most practical. Long-range EVs sell because they're desirable, not because they're the best match for the average person. I have no doubt that as soon as reasonable city infrastructure exists for EV charging, there'll be a lot of BEVs with small batteries for driving around the city.

You can size the PHEV range extender engine to be much closer to the steady state power requirement, and tune it towards such as well. The BMW i3 uses a literal scooter engine for the range extension.

The i3 can't do more than 40mph when using the scooter engine.

It can do more than that, especially if you've got the Euro-spec Hold State of Charge coded to be enabled. With HSOC, you just drive as normal and the scooter engine tries to keep the battery at the charge level you turned it on at. You only really notice that the car is noisier.

People do not just buy cars for daily commutes, it doesn't make sense to solely design around that.

That's my point exactly, the buy the EV to be dimensioned for the occasional weekend trip, but could often be much better of with a car with EV dimensioned for the daily commute and use ICE for the couple of long trips. This would likely be more cost efficient and ecological.

Don't get me wrong I like EVs, but the current crop's design is not such a straight forward winner in terms of ecological footprint over PHEV as many EV fanboys believe.

The current focus on long ranges is largely because Tesla is leading the charge in electric vehicles and Tesla is an American automaker. Commutes are often longer and conditions vary widely across the country and from season to season making predicting the true range difficult.

Plug-in hybrids may make sense, but I would imagine that including both a full power ICE and electric motor together and having them work together makes a more complex vehicle with more potential points of faliure. You also have the added weight of the duplicate components. The Chevy Volt, for example, weighs more than a base Model 3 and only slightly less than the long range configuration of the Model 3.

I feel like at least some of this depends on whether the ICE in a hybrid is coupled directly to the wheels or not. I believe in all current consumer vehicles it is, but there are other applications like hybrid trains and city buses where the engine is just running a generator at a constant RPM. Surely that kind of configuration would be the absolute best case scenario for ICE efficiency, and probably even for overall system efficiency (with battery loses accounted for) depending on the ratio of city to highway driving.

In a Chevy Volt, there’s a mechanism that mechanically attaches the motor to the wheels at speed above 35 mph for greater efficiency but below that it is a pure serial hybrid, disconnected from the wheel directly. But it rarely ever runs the engine. Pretty much only if you run out of charge.

Ah, spiffy— that's neat to know that it can switch modes like that. Looks like this has been a matter of evolution over time, too:

https://www.greencarreports.com/news/1096942_2016-chevrolet-...

I guess if you were only connected at higher speeds, that would also greatly simplify the transmission story, since you probably no longer need 1-3.

The Chevy Volt actually uses a continuously variable transmission for that. Makes it sound really weird as there’s not a direct correlation between the sound of the motor and the speed you’re driving.

There are some consumer BEVs with range extenders which work this way too eg the BMW i3. However they tend not to be marketed as PHEVs as such.

It seems that most driving in city streets by individuals is largely unnecessary: items can be delivered (by EV) instead of picked up and commuting can largely be electronic. Long term, it seems that the most important use case for the personal vehicle could end up being long distance travel.

Personal cars act as like a personal room on wheels. Peopl store stuff there and use it as a place to retreat to at work. “Personal vehicle as private space” is a super normie idea, but it’s weird how little play it gets in these conversations. It’s NOT replaced by rideshare or public transit.

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