by "Neil drives a beetle and a fancy beetle" (1500sand535)
Published 04/19/2017 at 14:13
by "Neil drives a beetle and a fancy beetle" (1500sand535)
Published 04/19/2017 at 14:13
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STARS: 1
Recently, my wife and I were test driving a Ford C-Max. And ever since, I’ve been thinking. Why don’t they put the electric motor in the rear wheels, thereby making the thing AWD?
Why don’t more auto makers do what happens in the I8, where the gas engine drives one set of wheels and the electric engine drives the other set? To my feeble mind, it seems like it would be easier to separate out the two systems and then you can advertise all-weather capability of your AWD. But I really don’t know much about this, so I’m guessing there is an obvious answer.
The Kia niro release had a lot of hedging in the press release about how they kind of wanted it to be AWD but the packaging didn’t work.
What am I missing?
"Smallbear wants a modern Syclone, local Maple Leafs spammer" (smallbear94)
04/19/2017 at 14:20, STARS: 0
I’ve wondered this myself
"OpposResidentLexusGuy - USE20, XF20, XU30 and Press Cars" (jakeauern)
04/19/2017 at 14:23, STARS: 1
My parents 2006 RX400h AWD is set up like this. The black area of this picture is the actually a “screenshot” of the Trip Computer Energy Monitor in an RX400h.
"TheTurbochargedSquirrel" (thatsquirrel)
04/19/2017 at 14:24, STARS: 0
It has to do with ease of assembly. In the i8 you have both the motor-engine assembly in the rear of the car as well as another motor in the front. These have to be installed separately and then interconnected once they are in the car. With the systems you find in most cars you can build the entire hybrid powertrain outside of the car and then drop it in as one large part. It’s similar to how the drivetrain to a traditional FWD car is installed as one preassembled part. It’s just easier and more efficient to build the powertrain outside the car and then drop it in in one step instead of multiple.
"jimz" (jimz)
04/19/2017 at 14:25, STARS: 2
What am I missing?
The C-Max was an existing car turned into a hybrid for North America. No room to account for a powerpack in the rear of the vehicles. The i3 and i8 were designed that way from the start.
"Textured Soy Protein" (texturedsoyprotein)
04/19/2017 at 14:27, STARS: 0
It’s called a “through the road” hybrid . As in, the only thing that connects the gas and electric motors is the road.
PSA has a system called HYbrid4 that does something similar.
Acura sort of does this with the NSX, and RLX and MDX hybrids but they also have an electric motor integrated into their transmissions which are connected to the gas motor, basically shoved next to the flywheel. But there’s still no driveshaft connecting the two axles—the axle that doesn’t have the gas motor has two electric motors.
"OpposResidentLexusGuy - USE20, XF20, XU30 and Press Cars" (jakeauern)
04/19/2017 at 14:28, STARS: 0
Toyota put a AWD Hybrid system in theRX400h although they had a gas AWD platform to base it off of already.
"Flyboy is FAA certified insane" (flyboy396)
04/19/2017 at 14:29, STARS: 0
As I commented on Ballaban’s review of the Mini Countryman, I want the S model Hybrid. It uses a scaled-down version of the i8 setup for an all-wheel-drive crossover.
Most companies don’t do the AWD thing to preserve interior space.
"LongbowMkII" (longbowmkii)
04/19/2017 at 14:30, STARS: 0
mostly this, but I could see not wanting to give up rear seating/cargo room as well
"random001" (random001)
04/19/2017 at 14:33, STARS: 0
“What am I missing?”
....$$$$
"Neil drives a beetle and a fancy beetle" (1500sand535)
04/19/2017 at 14:39, STARS: 0
This makes sense but again in my head, (which isn’t always right) I was thinking since in cars like the c-Max, they are putting all the electric batteries out back, the electric motor could go in with that as well. In terms of oneinstallation in back and then everything gas up front.
"Neil drives a beetle and a fancy beetle" (1500sand535)
04/19/2017 at 14:40, STARS: 0
Having a name for it helps me do more searching, thanks!
"Neil drives a beetle and a fancy beetle" (1500sand535)
04/19/2017 at 14:42, STARS: 0
Yeah, I guess I was thinking that some already created electric motor that could be put in with an already created gas engine would be cheaper than building the two systems together but it sounds like that’s not necessarily true.
Also, space!
"Neil drives a beetle and a fancy beetle" (1500sand535)
04/19/2017 at 14:44, STARS: 0
Seriously, if those countryman hybrids were coming off lease right now(they were 2 years old), I think on paper, it’d be our leading contender for a new family hauler.
"jimz" (jimz)
04/19/2017 at 14:45, STARS: 0
especially considering how much they gave up for the battery as it was.
"Future next gen S2000 owner" (future-next-gen-s2000-owner)
04/19/2017 at 14:45, STARS: 0
Packaging most likely, plus the added cost of axles. Also, they may have a platform that wasn’t readily adaptable to AWD or packaging requirements.
I don’t think it is because it isn’t a good idea, just other practical limitations.
"TheTurbochargedSquirrel" (thatsquirrel)
04/19/2017 at 14:48, STARS: 0
You don’t want to split the electric from the gas like that because it would eliminate your ability to use the gas engine to charge the batteries. When they are together you can recharge the batteries by using the electric motor as a generator in combination with the gas engine. When you split them like that the only ways to recharge the batteries is regenerative braking and from a charger.
"Neil drives a beetle and a fancy beetle" (1500sand535)
04/19/2017 at 14:49, STARS: 0
Charging. That is a big one and makes sense. Thanks
"Neil drives a beetle and a fancy beetle" (1500sand535)
04/19/2017 at 14:50, STARS: 0
Interesting combination of both. Thanks.
"OpposResidentLexusGuy - USE20, XF20, XU30 and Press Cars" (jakeauern)
04/19/2017 at 14:53, STARS: 0
Toyota has been at this game a long time by now. There’s a reason why my parents RX400h is still on its original battery after 350,000 miles and being used by customers as a loaner vehicle just about every day. Also, it was so cheap I rather take it to Home Depot and load up mulch and the like because the RX is easier to drive around the yard(and has AWD that tears up the grass less than the fiances RX350 would) than my dad’s heavy and massive Tundra Platinum.
"Flyboy is FAA certified insane" (flyboy396)
04/19/2017 at 14:59, STARS: 0
If you’re not too worried about upscaleness? I’d consider the Kia niro
"bhtooefr" (bhtooefr)
04/19/2017 at 15:11, STARS: 0
So I’m going to regurgitate some of what has already been said, but...
It does mean that you get to reuse your stock internal combustion powertrain as-is, and you get AWD.
However, it doesn’t make things simpler. You now need a second differential, you need an independent rear suspension to avoid high unsprung weight, and you need driveshafts to the electrified wheels wheels. On the software side, you now need to handle throttle mapping between two power sources, including traction control, and starting the engine while in motion. You also need to handle ABS mapping differently (although that’s the case for any hybrid).
Then, it’s simply less efficient when the electric motor’s in the rear - less power can be regenerated off the rear wheels than the fronts.
As others have said, this is a popular solution for adding AWD to an existing hybrid powertrain, though - Toyota uses this a lot on the hybrid crossovers, in addition to a power split transmission up front, which I’ll explain now.
Contrasting to something like the C-Max you test drove... it uses a very different transmission - a power split transmission - which is actually far simpler than even a manual mechanically, in the basic form that Toyota, Ford, and now Chrysler (with the Pacifica Hybrid) use. It has a planetary gear set and two electric motors, and never changes gear - one motor just spins at a target speed to hold the engine at the desired RPM, mechanically pulling a percentage of torque (in the mid 20s or so - and note that that’s torque, not power, it’s possible for there to be 0 power, or 100% power, going through the electrical path) off of the engine and sending it through an electrical path to the second motor. The effect is like a CVT, but more responsive, while also being a hybrid, and with no wear items.
Now, some automakers will use a sandwich hybrid, putting a thin motor between their transmission and engine. This works , but it’s where it starts to make more sense to do a through-the-road hybrid like the PSA HYbrid4 system, or the 225xe/Countryman S E ALL4/i8 system (I’m counting them as the same system, even though the i8 is significantly more powerful and reversed in layout) - except for the suspension and driveshaft changes, you end up putting a lot more crap in the bellhousing, and you have to have more clutches to shut the engine down in motion. However, it’s still simpler to put all the motor(s) up front IMO due to those suspension and driveshaft changes, and the changes to vehicle dynamics. One huge problem with through-the-road hybrids is... your car actually switches between RWD and AWD/FWD (depending on battery state of charge) when you drive it, and in slippery conditions, that could catch you out.
Oh, and a through-the-road hybrid... you can actually charge it when not braking, but you have to be rolling (you regenerative brake the rear wheels while the front wheels are driving the car). No charging it at a stop.
"Mach-inator" (Mach-inator)
04/19/2017 at 15:16, STARS: 0
Putting it all in the front of the car would allow one large cargo space (for big things) at the rear instead of splitting a cargo area at the front and rear (for not as big things).
"Shift24" (the-nope)
04/19/2017 at 16:37, STARS: 0
I like Honda’s version in the Accord, its some what complex but simple at the same time. Koenigsegg uses something similar on the regera
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