2011 Hyundai Sonata Hybrid First Drive

[Right Lane Cruiser]

Finding the White Space in Green

Jason Kavanagh - INSIDELINE - July 19, 2010

We've already seen how incredibly efficient the 6spd manual transmission gas powered version is... What will this car be capable of?? --Ed.

Just when you thought you've seen every permutation of hybrid, Hyundai goes and tweaks the formula a bit. You know, just a bit.

Fundamentally, the hybrid powertrain in the 2011 Hyundai Sonata Hybrid — Hyundai's first — can deliver that golden moment of silence made possible via electric-only propulsion, which is not so unusual. And during other driving conditions the electric motor's twist can be blended with the gasoline engine or disabled entirely. Again, not unusual.

In ideal conditions — a fully charged battery, no accessories, the right ambient conditions and driven by a totally committed eco-weenie — engineers report that the Sonata Hybrid can briefly touch 62 mph in electric-only mode.

OK, that's a bit unusual. It's also not something that's likely to be replicated in the real world. That's the difficult part.

Mixing the Cutting-Edge and the Familiar
Really, though, Hyundai's hybrid strategy deviates from the norm in its deliberate and strategic combination of the cutting-edge and the familiar.

There's a familiar power plant under the hood of the 2011 Hyundai Sonata Hybrid. You'll find the direct-injected 2.4-liter inline-4 from the base-model Sonata, although in hybrid form it's been changed over to the Atkinson cycle in order to boost its efficiency. The engine all by itself generates 169 horsepower at 6,000 rpm and 156 pound-feet of torque at 4,250 rpm. A 30-kilowatt (40 hp) electric motor is sandwiched between the engine and... [Read More]

[EVuser]

LiPo. Interesting choice.

[PaleMelanesian]

Atkinson engine. I wonder how much it would take to transplant or graft this into the gas-only car... It could be a simple as a cam swap.

[lxmike]

Who are they calling an eco-weenie??

[PaleMelanesian]

Totally committed and weenie don't belong in the same sentence. It just doesn't make sense.

[jimepting]

Originally Posted by PaleMelanesian

Atkinson engine. I wonder how much it would take to transplant or graft this into the gas-only car... It could be a simple as a cam swap.

Um, I don't think it that simple at all. First of all, everything in the power train of modern hybrids, especially those employing ATs and CVTs in under computer control. Just swaping cams would probably screw up everthing.

I'm still trying to understand the "modern" adaptation which is popularly called Atkinson cycle. Just for starters:
1. It isn't a true Atkinson cycle since the four functions, intake, compression, power and exhaust don't occur on one revolution of the engine, but two.
2. There may be a small offset of the cylinder and main bearing centerlines to mimic some Atkinson characteristics. I know that this is done in the Insight 1, but I have not been able to verify that it is done in the Toyota and other engines. This measure apparently lowers frictional losses as well.
3. Most writers seem to concentrate, as you indicate, on the revised cam timing as the major difference between the modern "Atkinson" and the more conventional Otto cycle engines.

Has anyone found a good, detailed technical explanation of all of the features of the Toyota engine? I did some browsing, but most sources are pretty skimpy.

[Butterfly Mage]

It looks like a real contender. If the 30 KW electric motor is sandwiched inbetween the engine and transmission, isn't that more like a beefed-up IMA than a scaled-back HSD? It seems to have a lot of horsepower available given the estimated 40 MPG.

[peacefrog_0521]

Weenies, sandwich, and strained plankton.
Sure this guy isn't their food critic?

[WriConsult]

I really like the architecture, but echoing EVuser I've already stated my concerns on numerous occasions about the use of LiPo batteries.