Featured Hyundai IONIQ - Prius competitor?

Thank all y'all for the explanation about transmissions, downshifting and ratios. Obviously, there was more to the story. My Acura was a RDX, and the BMW is a Z3. 'Apples and oranges.'

But my point was, I very much disliked the fact that the RDX could not go up even the slightest hill without downshifting, and it wasn't that smooth of a downshift.

Over the course of a tank of gas, both vehicles delivered close to the same fuel efficiency. The BMW does a little better in town, and the Acura a little better on the road. But they averaged out close to equal.. (The BMW would do better if I didn't enjoy running through the gears so much)

 

I did really much enjoyed the discussion about the comparison of the new hybrid layout that is taking place in the market, DCT+single motor and small generator for starter (Hyundai, Honda, VW) vs Toy 2 motors+PSD.

I would like to add that the 2 motor layout implies the continous re-circulation of power btw MG2 and MG1, with the related losses due to motor efficiency and current passages in wires: this equate to reduced efficiency at high speed . I guess to have a direct transfer of power due to a clucth, it makes a difference. It is likely that Hyundai claim of better than Prius HWY FE comes from this precise aspect.

Anyway i'm not expecting an average real life FE better than the extremely optimized Prius IV result. IMHO the real difference is that the HSD system is getting the peak of max possible efficiency with reasonable cost, and the other layout have some room of improvement ahead. Would have been possible to work on that DCT-single motor layout in 1994/1997 for a competitive small hybrid? I don't think so, i think at that time there were not other genial layout conceivable other than HSD. But maybe now could be the time of something different.

Anyway, Honda i-DCD, the DCT 7gears-single motor Honda layout, shown many reliability and optimization issues, and the Fit hybrid is still, after more than a year, on sale in Japan only. So the new technology have probably yet some reputation and reliability to build up. But for example, the oil-driven VW 6 gear DCT (the one fitted on VW hybrid Golf GTE), have already many years of good reliability performances. It was the dry clucth 7 gears that was and still is a wrong, cheap and unreliable design of the VW rip-off age.

A couple of indications of a change in strategy however comes from Toyota too: the october 2015 patent for a PSD with a (single?) clutch for "high speed EV", and the just presented high powered powertrain on the Lexus Lc500h, with a 4-speed automatic gearbox stuck on a 2 speed e-CVT gearbox.

 

+1

Agree that at least in stop and go the hsd is going to continue to give better fuel efficiency. I'm not so sure the prius does better on long road trips, long commutes, or hypermiling, YMMV. Definitely should still be room for improvement but hyundai is on their second generation system.

No you couldn't do this in 1997. Hyundai said on the sonata hybrid that they needed electronic advances for the engine to rpm match for the motor. That probably has only been around a decade. Even though dual clutch transmissions have been around since the 80s, the first lower cost fwd one didn't come out until 2003. The first dual clutch was in a porsche, the first transverse dual clutch was vw. Hyundai only got their first dual clutch recently. My guess is smoothness and cost on the dual clutch for hyundai, ford, etc have anouther decade of advancement ahead.

That less reliable dsg was about cost and weight cutting, which I'm sure you can do, but its not simple. A low powered hybrid should need a much less expensive transmission than a 6 cyclinder high powered dsg. VW did it wrong.

Yikes! I think that looks like a giant frankenkludge, but is probably better than the poorly scaled system on the Lexus LSh. I think you mean variable speed e-cvt, and Lexus said the two transmissions put together act like a virtual 10 speed with virtual gearing built into software for the e-cvt. I think IMA (should be out of patent) to the regular 10 speed + a front axis (more regen braking comes on the front) motor might have been simpler and cleaner. My guess is this does not get good mpg, just a step up like gm's two mode with rather high cost for the system.

VW's dsg stands for direct shift gear-box which is a dual clutch not a regular step automatic. These dual clutch gearboxes are more efficient and shift faster. That new lexus 10 speed is supposed to shift in a fast 400 ms, but typical vw dsg's shift in 200 ms, and that time is mainly taken to change engine rpm and clutch in.

A dual clutch really acts like 2 manual transmissions. 1 has the odd gears and reverse, the other transmission has the even gears. Two clutches shift between which transmission is engaged, so the shift itself can be much faster than 100 ms, with the next gear pre selected, the an upshift itself takes less than 10 ms. The extra time is used to match revs between engine and transmission then to clutch back in smoothly. In a hybrid configuration, the motor could more quickly slow the engine for rev matching upshifts, and boost the engine for rev matching downshifts.

 

We have one data point: Steenman: Portland Green Test Drive. What we did and why we did it. | Steenman Associates

• 2009 Cheat-diesel Jetta, 2.0L, 41.4 MPG, vs 2008 Prius, 1.5L, 40.06 MPG (". . . we drove these cars HARD like real people . . .")
  
  • The 2010 Prius reduced the Cd, transaxle overhead, and the 1.8L engine significantly improved high power efficiency with cooled EGR.

Also, @Eric Powell or some of the former Hybridfest fans can confirm but I remember Wayne Gertes would 'borrow' a Prius for the driving contests. Perhaps one of the Gertes fans might have more history than my old-man memory. Granted Gertes enjoys his driving style in non-Prius cars which may be a profession.

Bob Wilson

 

I'm sure the hyundai will beat the gen III prius on cruise control. Its more efficient than the gen III engine (40% vs 38%) with likely more efficient transmission and similar rolling resistance and drag, YMMV. I'd say the gen IV prius is where you compare, and not the 2 eco, which does some tricks that may hurt drivability so its not a good comparison, unless you lose the spare and put lower rolling resistance rubber on the ioniq.

I'm sure gerdes will do well in the ioniq given the set up. Where the gen IV shines is non-hyper-mile acceleration from 0-20 versus this car. Look what he did with a sonata hybrid before the fix. The ioniq has lower drag and more efficient engine and transmission.
Wayne Gerdes: After 2,269 miles and 59 mpg, Hyundai Sonata Hybrid "kicks nice person"

This is not your father's tdi. The original sonata hybrid suffered on city mpg. The trick will be how well the ioniq with its improvements does here. The sonata does great on the highway.

 

That is what the Press Releases say.

Bob Wilson

 

If automated bump starting has reached the point for commercial implementation, the starter doesn't need to be any beefier than what start/stop systems have. Depending on costs and efficiency, a starter may just get deleted.

In regards to the Ioniq, any savings Hyundai has in their system over the Prius one likely went to the larger battery.

A step transmission is the 'normal' automatic. Of one motor hybrids, only the Sonata mates the motor to a step transmission that I know of for sure. The old IMA used a manual or CVT. VW used a dual clutch transmission like the Ioniq and Honda's new system. I can't recall if Nissan used a DCT, step, or CVT.

If a better gear ratio means better fuel economy, then downshifting at times isn't down. The issue, and your real complaint, is about automatic type transmissions with hard shifts. Every once in awhile the Sonic does a hard shift, and it is jarring. Most of time they aren't. Compared to a CVT, they are noticable, but not intruding. I can take either one, but can understand if someone else has a strong preference either way.

All else being equal, a DCT will shift smoother than a step automatic, and be smoother and faster than a manual. But transmissions are designed and made equal. From the few reviews, the Ioniq's sounds to be on the better side.

Yes, technology and costs are now making better implementation of parallel hybrids possible.

Honda didn't bring the Fit hybrid over back when it was using IMA, unless you count the Insight2. The software abusing the battery was a well known issue with the old IMA system. No news about problems with the new system. Honda holding hybrids back in North America has more to do with the cost of gas.

Wayne would also ask to borrow an original Insight for competitions. Depends upon the route.

 

An on-road comparison, Wayne Gerdes style, would be the best way to evaluate the Prius and Ioniq because the Ioniq's ECO-DAS charging system, that optimized battery charging and electric boost according to terrain, won't work on an EPA-style dyno test. Actually, EPA tests don't show either car to its best advantage.

 

Mr. Gerdes already sort of showed which test would favor each car. The ioniq would be favored if driven like he did the sonata - cold weather, higher speeds, long distance. Here the hyundai software helps his pulse and glide even at higheway speeds. The test he did for ford fusion would favor the gen IV prius, low speeds lots of traffic and lights. He did that sonata type test to show poor highway mpg for the ford c-max hybrid versus the prius liftback and prius v. It would be neat if he did both to show how each faired but, I consider these as stunts for the best you can do, not how you would commute on an everage day.

A beefy starter motor is not expensive. It adds to reliability in cold weather and smoothness. The other part of the start stop system - the battery is already there. Mazda is leading in non starter starting, but sofware is complex and there are limits on temperature.

prus has a 0.75 kwh battery sonata 1.5 kwh battery, that makes it 0.75 kwh more. If the battery costs $400/kwh which may be higher, that is an extra $300, or total battery cost of around $600 before mark up by hyundai. Ford chose panasonic over lg probably partially on cost, my guess is lg dropped there price to get the design win.

 

Indeed
But of course this powertrain is for increased performances and not fuel economy...

An interesting paper, about simple planetary gear trains, but with some clutch in btw... could it be the future for a PSD? :

Novel Configurations for Hybrid Transmissions Using a Simple Planetary Gear Train
Huu-Tich Ngo and Hong-Sen Yan

"This paper presents a design approach to systematically synthesize feasible configurations for series–parallel and parallel hybrid transmissions subject to design constraints and required operation modes using a simple planetary gear train (PGT).
The configuration synthesis process includes two main steps:
(1) assign inputs and output powers to the PGT subject to design constraints by the power arrangement process and
(2) assign clutches and brakes to the obtained systems subject to desired operation modes by the clutch arrangement process.

By applying the proposed design approach, 9 clutchless and 31 clutched configurations for series–parallel and parallel hybrid transmission systems are synthesized, respectively. For each type of the hybrid systems, we analyzed kinematics and power flows of a new configuration to demonstrate the feasibility of the synthesized systems. The design approach can be used to systematically synthesize future hybrid transmissions with different mechanisms, design constraints, and desired operation modes. "

If i try to insert the link, i get the msg "oops, something went wrong", so PC problem not sorted. Add the pieces to get the link:

http
://mechanismsrobotics.
asmedigitalcollection.asme.org/
article.aspx?articleid=2480976#ANewSeries–ParallelHybridTransmission








merged.

The IMA Fit Hybrid, Jazz Hybrid in EU, was imported and sold in EU. Actually i'm not sure but it could be that was assembled in the UK where our EU Civic hatchback is produced. Excellent car the Jazz Hybrid, not a huge success because the price. Then came the Yaris hybrid. a lot cheaper and with better FE, and killed completely the poor smart Jazz Hybrid.

But for the new i-DCD is plenty of news from Japan, it was unusually troublesome: after 3 recall and upgrade, they started even changing the whole trasmission on the first cars sold. It was like that for quite a time. I'm not anymore into informing me because, at the end, Honda decided not to import the new Jazz i-DCD Hybrid in EU. And for the time beeing, is only sold in Japan, i guess because they are still unsecure...
So i guess holding hybrids by Honda is probably something more tricky than the gas price.

Here we are:
Green Car Congress: Honda recalls Fit Hybrids and Vezel Hybrids in Japan; 3rd recall due to problems with 7-speed DCT

Well, actually the recalls became 5 in the meantime...:
Honda: Climbing Out of the Recall Pit - Japan Technology Report - Nikkei Technology Online

 

This article is behind a paywall so I haven't read it but it sounds similar to another paper I read a year ago. They seem to model just variations on one or more planetary gear sets and not anything like the new Lexus with a basic Lexus/Toyota hybrid system and a 4 speed automatic stuck after it to allow dynamic changes to the final drive ratio.

Toyota seems to do very well with their existing design for mainstream HEV cars so I doubt they will change it much. I do think there is good chance they will adopt more of a Volt-like two-mode transaxle with dual motor linkage approach for future PHEVs with bigger batteries. Toyota has recent patents for this but it's not clear if this will show up in the next Prius PHEV -- the new design may not be fully ready and the new battery pack may not be large enough yet to make such a change worthwhile.

 

yes of course they are anything like the new Lexus layout that makes use of the e-CVT as a substitute of a torque converter: i did indicated the paper for possible simple solution in giving, throug clucthes, some upgrade of the PSD. And it sounds like the intention of the authors... whether this is connected to Toyota i don't know.

 

Honda's hybrids tend to be pricier than the competition here too.
In hindsight, the Fit hybrid might have done better here than the apparent Prius wannabe of the Insight2. Alas, it never arrived.
Honda has held the Accord hybrid back a year for improvements to that hybrid system.
Is this Honda's first DCT? Despite the reputation they have for reliability here, they have botched it on some of their automatics in the past, and maybe their early CVTs.

 

Honda uses an 8-speed DCT combined with a torque converter in the Acura ILX. I hear it's pretty sweet if a bit shifty.
Honda's new 8-speed DCT uses a torque converter - SAE International

 

So, it's not 155 ev after all! Hyundai IONIQ Electric Has A 28 kWh Battery, 105 Miles Real Range

 

huh. go figure...

 

Well, actually we already realized it when we discussed about the first statement of 155 miles: it was european cycle and the guy from Hyundai mentioned the Leaf as comparison. They end up just 2 miles short for the 2kWh less. Leaf is the commercial target.

 

Again NEDC vs EPA estimates...
Fortunately WLTC will take place next year.

 

One of the comments pointed out that the Korean price is close to the price of the Spark EV. Which starts at $26k in the US, and the longer range Leaf at $34k. So Hyundai has a chance of seizing the entry level BEV market if they keep the price low in the US. The range is still a disappointment, but 100 miles beats the 80ish of most everybody else, and the next Leaf likely isn't going to drop in price. As long as it isn't CARB market only, it can carve out a niche in face of the 150+ mile BEVs coming, and help expand total plug in ownership.