Featured Hyundai IONIQ - Prius competitor?

i think motor trend was deceived by the pics they had of the rear end. it is hard to tell where the hatch seams go when the reach the rear window.

 

I thought we could compare and contrast the drive systems of the Prius vs Ioniq. I'm speculating that the Ioniq will have the same hybrid drive system as the Sonata which may not be the case.

• Ioniq has Lithium polymer batteries as standard equipment and twice the battery capacity of the Prius.
• The Ioniq has an 8-speed transmission and a clutch that can disconnect the engine completely from the drive making the electric drive more efficient and allowing for electric-only drive at freeway speeds.
• The Ioniq can downshift during deceleration thereby spinning the regenerator motor up and getting more efficient regen.
• The Ioniq can open the clutch during deceleration thereby removing any engine braking from the regen making regen more efficient. If the battery is full, the clutch can stay engaged and the engine can be used for increased braking.
• The Ioniq can be manually shifted allowing the driver more control over the transmission.
  
• The Ioniq has a belt-drive starter motor and the belt requires periodic inspection and replacement.
• The Ioniq always starts from a complete stop in electric drive and starts the engine later. This hurts 0-xx acceleration times compared to the Prius which can use both motor and engine drives from standing start.

What have I overlooked or gotten wrong?

 

This is probably a 6 speed dct (double clutch automated manual) using the electric motor instead of the slushbox like the sonata. The 8 speed information was released at the same time leading to confusion that it would use the newer transmission, but the old design saves $ and weight, while probably not impacting efficiency. (change to second bullet point)

Engine is 1.6L di 105hp Atkinson design reaching 40% efficiency.

On last bullet point, I would wait until there was a test and more information. My guess is the hsd will have better 0-30 time no shifts, the ioniq will have better 0-60 time with better power to weight.

Both gen 4 prius and ioniq promise better NVH on the newer more efficient engines compared to gen III prius.

 

Discussions like this will be engaging (pun intended). It's a nice change from the past with others...

We've learned over the years that factors of that nature are overly simplistic. Efficiency of the converter/booster alone could cancel out any non-mechanical advantage. There's also the penalty caused by having to re-engage, rather than just having a power-carrier free-spinning. Also, EV only driving comes with a tradeoff when the electricity source is a gas engine.

It will be quite interesting to learn how an 8-speed transmission interacts with a hybrid system. That's far more complex than a continuously-variable transmission.

Prius doesn't start with the engine either. The current generation waits until 10kW of power is requested before the gas engine is fired up.

How's that any different from Prius? Kinetic energy is transferred from wheel to generator when decelerating. The transmission simply transmits. 8 gears verses infinite (continuous) gears.

Sounds like more electricity will be consumed than just having a planetary connection already spinning, or at least a wash. It will definitely be slower too.

 

until GenII PiP news confirms what EV range it will have, combined with its CS mode, & then we get released info of the same data for the Hyundai plugin, it's an open race. Price will matter too. To the victor go the spoils. Even so, the body style of the Hyundai sure treats my eyes a lot easier.
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I doubt it will hit the Prius reliability. Prius has takken baby steps since 2003, which means they have had 12 years to work out just about all the kinks.

Hyundai is pretty good at pricing their models. I wouldn't be suprised if they took a loss for the next few years to price it competitively. I guess we will find out when we find out. No price yet on the gen IV prius or any flavor of this hyundai.

 

I agree, based on the pictures seen thus far. I'm still not sold on the interior however, but then, I don't particularly like the "darth vader" interior of the Prius.

BTW, I appreciate all of the discussion above. I am not an engineer, and have no way to evaluate the pros and cons. I rely on y'all to keep me informed. The only problem is, so many initials are used, I sometimes have to go search for what y'all are talking about

An engineering question: (a question. Not a debate)
Years ago I changed the SOHC cam in my Pinto. I was overwhelmed with the force required to turn the cam (overcoming valve springs pressure). Wouldn't a small ICE with a solenoid valve action, turning at a constant (peak efficiency) rpm, driving a electrical power source, be the most efficient combination of propulsion?

 

Both the gen IV prius engine and this hyundai engine have very low friction which helps them get to 40% efficiency. Electronic valves won't take engine power to operate, but will require electrical power off the alternator, battery, or m/g. I doubt you will see increased efficiency for going electronic. from eliminating parasitic valve energy losses

Electronic valves allow some cool control of combustion though. If you go electronic inlet valves you don't kneed a throttle plate (except for cooled egr, but maybe something could be substituted). Prius gen III valves allow 9:1 - 6:1 compression, electronic would allow a bigger range, and different characteristics to control swirl of in coming air. Electronic exhaust doesn't seem to provide many advantages for design. The skyactiv has electronically controlled valves. It gets expensive for electric valves that work well at high engine rpm.

 

Camless valve drive has been sort of the holy grail of 4-stroke engine design for a long time. Various pneumatically operated valve systems have been tried with varying degrees of success but we never seem to see them for sale.What It's Like To Ride In A Car With The Camless Engine Of The Future

Regarding the Ioniq's gearbox, I don't see why a DCT would be used over the Sonata's gearbox. The Sonata's transmission isn't a slushbox, of course, because it has no torque converter and it should be easy to separate the drive from the wheels with a single-clutch system.

 

It's different because MG2, that does regenerative charging duty for the Prius, has a fixed relationship to the wheels: Toyota Prius - Power Split Device, therefore as the wheels slow under braking, regenerative power falls off. Under Hyundai's system, the regenerative motor isn't fixed to wheel speed. As the wheels slow, Hyundai downshifts the transmission to keep regenerative braking force high and regenerative braking energy to the battery high.

 

The only time I see the braking-power exceed the regen-limit in the Prius is the moment before coming to a complete stop. Even with 8 gears, how much shifting would take place at that point? It doesn't seem like it would amount to much.

 

The definition that has been around for 3 decades is simple... if the back windshield lifts, it's a liftback, which this country calls a hatchback.

Interestingly, GM distants itself to an extreme for the sake of avoiding the "hatchback" label. That's why Volt doesn't have a rear wiper. They'd rather sacrifice the convenience of wiping the more-horizontal-than-vertical window than have it cosmetically resemble a hatch... which begs the same question of whether or not the production-model of Ioniq will do the same thing. Those spy photos imply Hyundai won't offer a wiper either.

 

But when Toyota doesn't have a rear wiper in the Prius Eco its for aerodynamic reasons....

 

They may partially do this because their setup has less flexibility over when the battery can be recharged whereas the Prius has total flexibility and can even run the engine to charge the battery when stopped, if needed. The Ioniq probably has to be more aggressive about recharging and maintaining an adequate minimum energy buffer.

The Prius doesn't need to disconnect the engine since MG1 will free spin when the engine off. Even though the engine is unclutched in the Ioniq, the electric motor will still be spinning the transmission components around with likely as much mechanical loss as MG1 spinning. I'd love to see real measured numbers on this.

It's true that shifting gears on an electric motor can help improve its efficiency for driving the car and regen over a wide range of vehicle speeds but 6 or 8 gears are overkill for an electric motor -- 2 is about right. Some efficiency may be lost momentarily during the unnecessary gear changes.

I doubt that gives any real advantage over the Prius which can just shutdown the engine during deceleration. Using engine braking during deceleration is something the Prius can already do when the battery is full.

This is true. The Ioniq will give the driver a conventional jerky shifting behavior and probably some control over shifting so they can drive less efficiently than the computer....

 

That's a configuration for a specific model, not an across-the-board standard. The consumer has a choice. Big difference.

 

You can say that again!

The hybrid/plug-in should simplify, not just adapt traditional design.

 

The consumer has a choice about whether to make their car look like a hatchback or not? That was the motive you ascribed to GM.

 

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