2014 Honda Accord Hybrid Gets 49 MPG in City Driving

Oh wow. That's actually kind of nice.

 

'because it's a Honda hybrid?

 

i got 60 in the hycam, perhaps toyota will send out a press release.

 

you can run, but you can't hide.

 

Can't believe they copied the awful 4 spoke steering wheel design of the Prius.

 

i absolutely believe in expanding the pie, but i would love to see some real advancements in hybrid technology, not just we have one too mentality. i'm hoping honda has something exciting here, but if it winds up being 40 mpg and honda afficionado's dig it, that's not a bad thing.

 

And yet the next gen Rav4 thread in the hybrid news section was never moved to other cars.

Let's hope the real world lives up to the hype.

 

It looks promising but I have a concern.

The way it works is in contrast. It is either series hybrid (gas -> generator -> motor) or direct gas engine drive (single speed). It doesn't seem to do any blending of the two to get infinitely variable torque output, like HSD.

Low to mid speed is covered by the electric motor (power from the battery, gas generator, or both). High speed is done with a single gear gas engine.

The setup may perform well for EPA test cycle because the controls to switch between the two modes can be optimized. The question is the fuel economy in the real-world driving, especially aggressive driving or the type that forces the series mode. It could be a hypermiler dream car due to the direct mechanical drive mode. I am concern that mode will be of limited use for "normal" drivers.

 

Look forward to seeing the real world mpg.

 

Cool, too bad the IMA is basically a regular gas powered car with all the maintenance and moving parts.

 

Yes, that's my understanding from reading how it works.

Series mode will take conversion loss. Note, all the power from the gas engine will need to go through conversion. In HSD, it is a small percentage the way PSD is setup to split.

The direct clutch engine drive may be great for cruising at constant speed. Passing or acceleration that need to "downshift" may end up in series mode (taking efficiency hit).

 

Yup, eCVT is mechanically very simple. No clutches and nothing mechanical to shift. The only thing it shifts is the propulsion motor/engine -- continuous variably.

Gen3 eCVT is more powerful yet smaller and lighter than Gen2 (see below). It includes both electric motors. The only thing missing is the gas engine, inverter and battery that's not considered part of "transmission". To certain degree, I don't think we should include the electric motors as "transmission" in traditional sense. Which is why I prefer to call it hybrid transaxle.

It does more than the job of a tranaxle because it plays the roles of starter and alternator as well.

MG1 for Gen2 (left) and Gen3:


MG2 for Gen2 (left) and Gen3:


Power Split Device for Gen2 (left) and Gen3 (includes MG2 speed reduction unit):


Entire hybrid transaxle Gen2 (left) and Gen3:

 

Yes, absolutely. You don't want the gas engine rpm locked into the wheel speed. That lack of flexibility would restrict the ideal use of the gas engine at optimal BSFC.

The highest efficiency can be obtained by adjusting rpm or torque (see below -- darker area is 220 g/kwh) to get the needed power. Locking the wheel speed would only allow the torque adjustment to get to the lowest BSFC (less gram of gas to make the same power). So that limits possibilities since it can't adjust engine rpm.

Adjusting the torque to assist ICE could be limited (not as flexible as HSD) because, the traction motor will get the power from the HV battery. If the battery is low, generator will need to run. When that happens, it will be forced into series mode. That's because gas engine power cannot be split into both mechanical and electrical path at the same time. It is the "either or" situation. You don't have the persistent electricity availability made possible by the powersplit hybrids like HSD and Ford hybrids.