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Comment by msoad | Hacker News Reader

I think they're saying all powertrains are going to be electric. A i3/Volt model is way more efficient because it's not wasting any energy in idle mode like traditional model.

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fuel consumption while idle is quite negligible particularly when it comes to a MPG calculation. My car (and actually all european models over the last few years) have auto-idle when stopped. My stats are that over the 10,000 km I have driven since new I have extended my range by 85 km in terms of saved fuel (so approximately 4 litres saved over 10,000 km, or approximately 4/700 (700l being total fuel comsumption over those 10,000 km).

So i've saved half a percent of my total fuel consumption. Useless individually. But of course potentially enormous savings when rolled out to a fleet of thousands of cars

Great point. I go to drive in movies frequently with a Honda Odyessy, and idle most most of the time with the AC and radio on. It lowers the tank's MPG by about 3-4 miles.

Would love to see drive-ins providing a 120 outlet at the speaker box for EVs to plug in at, for using AC, radio, etc while at the movie.

EVs are great for "idling." Energy use by accessories is negligible compared to the capacity of the traction battery. Even climate control can be pretty reasonable. A Tesla can sit with the radio on and the air conditioner running and lose just a couple of miles of range per hour.

With a Porsche Macan S (which has terrible gas mileage) I can see a noticeable difference whereby in cold weather temperature (doesn't auto idle much) vs. warm weather I see about 2 mpg difference in city driving. Haven't done any specific calculations but that is what I have been seeing.

anecdotal, my z4 28i has start/stop and it functions quite well. the 2.0l engine is very efficient overall and while I have not tested the mileage with start/stop off I am pretty sure it contributes to the good mileage I get from this sporty car. The start/stop works with the car in neutral and the clutch pedal not depressed; this is a six speed manual from 2012. US numbers, I track mine on fueleconomy.gov and I do about 32-34mpg commuting and a recent 1800 mile round trip averaged 38-40 at 65-80mph freeway.

I could see electric motors taking the place of the drive shaft and trans axel arrangement. You could easily add "awd" to many cars by electrically powering the previously non drive wheels. The best use is launching as that is where my mileage dives.

I am not a fan of the i3 because of the compromises made to the iRex for CARB regulations. A slightly larger engine and fuel capacity are warranted.

Ideally what I would like to see for a car the size of mine; small 1 to 1.5l engine capable of driving the wheels direct after speed is reached with electric responsible for getting the car off from stop. Chevy does a great job with the Volt but I think batteries still have a long way to go considering the weight required for so little range most offerings have

Is the engine stopped while the car is moving? That would save even more fuel compared to only stopping the engine while stationary. A further improvement would involve starting the engine without using the starter motor when possible.

I could do all that with my old car "manually", but I only tried it a few times.

With most fuel injected engines, the injectors turn 'off' on deceleration until ~1000 rpm where they kick back on.

Do you mean they turn off while rolling in neutral or with the gear in? Sure, the injectors turn off when you're decelerating in gear, but that's true even if the car doesn't have a start-stop system.

However, I was talking about the case of decelerating in neutral with a car having a start-stop-type system. Rolling in neutral is always more efficient if the fuel is also cut off, but often even with the car running on idle.

Pretty much every single new car comes with Start/Stop technology nowadays,so it's a bit of a moot point.

I know the 5 series has stop/start idle elimination now. Does the petrol 3 series?

Yes, since 2008. Source my old car, a 318i 2008

And since at least the 2012 F30 3 series in the US, if not before then.

I rented a diesel 2014 1 series in Ireland that had it. If a rental 1er had it I imagine it's standard on all their cars.

The article specifically calls out that the 3 series will become a plug-in hybrid, so there will still be a gas engine directly powering the wheels, not just generating electricity.

The term "hybrid" does not indicate that a gas engine powers the wheels directly. A series hybrid can have a gasoline or diesel motor that exists merely to charge the batteries, as in the i3 Range Extender version.

The article specifically mentions the 3 series becoming a hybrid (not what type; the ActiveHybrid 3 and ActiveHybrid5 already exist for limited sale), but it also speculates:

"The new range of cars could be driven by separate electric motors powering the front and rear wheels, with a small gasoline engine to generate electricity to extend the range of the batteries"

So, basically, we don't know what their precise plans are, but the article does not indicate that the 3er will have a gas engine powering the wheels.

Whatever their precise plans are, I hope this finally means we can stop paying attention to Hyperarrogant Elon. :)

What a strange sentiment. Competition in this field will be excellent for consumers.

If you look at BMW's current marketing names for the i3 and the i8, it describes the i3, both with and without the REx, as "electric", whereas the i8 is a "plug-in hybrid", and does have a hybrid powertrain. Obviously it can be argued that the i3 with the REx is a hybrid, but it's clear to me that BMW intends to build an i8-like 3 series.

There will be a gas engine, but not powering the wheel, they're saying the 3 Series will be converted to an "electric drivetrain": the ICE only does electricity generation, transmission is electrical and only electric engines power the wheels (aka diesel-electric or "series" hybrid)

So pretty much like the current i3 with the "Range Extender" option or the i8?

Same principle, though in the RE i3 the ICE isn't intended to run most of the time, so the i8 is a better point of comparison: you can use it all-electric for short hops but most of the expected usage is with the ICE running and the battery serving as buffer & booster.

>> BMW is now intends to convert all its vehicles to some configuration of plug-in hybrid.

Yep, it's 'just' a "plug-in hybrid". Good for low emissions and high mileage ... on paper.

I'm perfectly happy with my Outlander PHEV as it reduced my real life fuel use to somewhere around 15%.

It has a larger battery than most plugins, and my daily commute is 98% electric.

http://www.voltstats.net/

Out of ~1300 Volts tracked, 70% of the miles traveled were EV only. Keep your snark out of facts.

Those stats are likely biased towards having a larger percentage of EV only miles.

Regardless, plug-in hybrids do reduce greenhouse gas emissions and gasoline used. They were a nice stop-gap until battery tech has caught up, and now that it has, you'll see people move on to fully electric vehicles.

Could you clarify / source / double-check that?

If you've got an electric drivetrain, adding a mechanical drivetrain: gearbox, driveshaft, differential, and powered axles, is a lot of additional weight. Powering a generator and transmitting power via electricity to the electric motors you've already got in the wheels makes a lot more sense.

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