Comparison with Hyundai ioniq?

I haven't been following the pros and cons of the 12v battery ...... but your last statement, "if the whole Li-ion battery is discharged, you cannot start the car" I think that would be true with the Prius as well. Perhaps, with the external belt driven starter/generator on the Ioniq, that would be a true statement. But my understanding is the 12 v battery in the Prius does not start the ICE. But either way .... if the "Li-ion battery is discharged" you have bigger problems than not starting the ICE. I think the hybrid system is designed to prevent that from every occurring. If the HV battery were to completely discharge, it would be due to a catastrophic energy management system failure, extended storage, or an electrical short.

Hopefully someone with knowledge will clarify your question.

 

If they are indeed using a 12V portion of the traction battery to eliminate a lead-acid 12V, that is probably a good thing (tm). One less battery to worry about. I would worry if it has enough capacity though. Lithium batteries are usually rather small in A-Hr capacity due to cost.

The Prius uses the 12V battery to start up the -electronics-, not the engine. The 12V battery is also a "ballast" for the 12V system, which is used to power the lights and entertainment systems, besides the vehicle electronics. The engine is turned over by the traction battery through the inverter (the inverter converts the 200V DC to about 560V three phase which is then used to turn a MG (motor-generator) to crank the engine). If the Prius is moving both the MG and the vehicle momentum can be used to turn over the engine. A 12V starter in a "conventional car" has about 1-2 HP and turns the engine at up to 500 RPM or so, but in a Prius, with 20 HP or more of power from the MG, the engine is spun at about 960 RPM. It seems to always start, no matter how cold or hot soaked, as long as there is gasoline in the fuel system and tank.

There are no gears shifted in the Prius eCVT, and there are no clutches. Instead it uses magnetic drag to change the "effective gear ratio" through the sun and planet gears and the two MGs. In neutral no magnetic drag is used so the engine can spin freely without affecting the wheels. For reverse, only a MG is used, driven in the reverse direction by the inverter (as you can see it's more than just a simple inverter). The other MG is used to add drag to pass the rotation to the wheels. This is why a Prius is power limited in reverse (try backing up a steep hill to see the limitation).

From what I've read the Hyundai uses a dual clutch transmission.

So far nobody has beaten the Toyota HSD, though both Ford and Nissan have copied it (and licensed those copies with Toyota).

 

yep the Ioniq does use a DSG gearbox, there is the difference

the eCVT in the prius is more efficient round town, but the Ioniq with its DSG is more efficient on the highway

 

Why should a DCT be more efficient on the highway over a CVT?
The only benefit of a DCT is fixed gear ratios, so it actually behaves similarly as manual transmission which is expected by most of the specimens from homo sapiens sapiens species.

 

We are yet to see IONIQ here in Australia, but what I read is that it's not the DSG (or eCVT), but the way it is designed. A bit like a BMW 5 series vs Mercedes E Class - won't be the same.

In PRIUS it seems more that city speeds use EV, and at highway speeds, it defaults to more ICE use, but both in conjunction as a hybrid. Whether it had a DSG or eCVT shouldn't matter to the outcome.

It would be interesting to see an IONIQ and PRIUS compared using hypermiling techniques over a set course.

 

Since Hyundai Canada won't publish the -actual- specs., such as the city/highway mileage (at least it isn't on their website), we can't compare them. Makes me wonder exactly -why- the specs. aren't on the website. Makes me very suspicious of their claims!

As I've already posted, nobody has so far beaten the Prius. Maybe their car is better, maybe it isn't. Would be nice if they actually allowed us to compare them!

 

I would expect the Canadian Ioniq mileage specifications to roughly match the US EPA estimates which are already available at fueleconomy.gov. Although the EPA numbers converted to liters per 100 km are not identical they are very close and the relative difference between the Ioniq and Prius efficiency shown on EPA numbers will likely hold for the Canadian ratings as well when they are eventually published in a few more weeks. The US and Canada use very similar test cycles and since 2015 are again in fairly close alignment.

http://www.autos.ca/auto-consumer-info/analysis-natural-resource-canadas-2015-fuel-consumption-revisions/

 

Looking at your Fuelly badge ... is the "UK mpg" something that they use in real life in the UK, given that gas is sold in liters (I do apologize: "petrol" and "litres" respectively).

 

We can compare UK mpg with US mpg easier rather than convert from l/100km, a US gallon is 4/5 of a UK gallon.

 

(slightly re-worded)

On the web-site MOTOR AUTHORITY, it states "Toyota has announced new 8- and 10-speed automatic transmissions that will be coming to replace a number of 6-speed and CVT units it currently uses"

Perhaps Toyota is moving in the direction of greater use of EV at higher speeds? Maybe CVT has limitations at higher speeds?
(I'm asking a question ... not making a point.)

 

we're up to 84 mph, so, i'm not sure where someone could use it legally, in the u.s. anyway. maybe they have discord a secret to better mpg's by reverse engineering an ionique.

 

Could be - technology steadily marches on. In 10 years time, we'll look back at the old days of 2017. The other thing is they're probably preparing for autonomy, for ever lowering emissions and fuel use on conventional engines - which has been steadily happening recently.

 

Well, my question was whether the Brits use the UK mpg habitually/normally or mostly on forums, dominated by US members.

 

Sorry, ole buddy. Can't answer for all Brits or all forums, but we have been mandated into buying gas by the litre, but distances were never changed to the metric system for roadways. So our Govt, (in its wisdom) saddled us with general measurements as metric, having abandoned the duo-decimal system of yore except for highways distances. Speedometers are in mph. Fluids have gone from pints, quarts and gallons to liters, so we are left in a state of no man's land. You work it out. If you're confused, think how we feel!

 

Oh dear, my head hurts - will it be Euros, Shillings and cents too? Oh, wait - with BREXIT, the Euro will disappear.

 

And its only a few years back that loose fruit & veg was still sold in lbs and oz.

 

Well.... we never actually went with the Euro. Just changed from 20 shillings in a GB£ to 100 new pence ('p') instead of 240 pennies ('d' from the Roman denarius). Of course, back then there were 12d to one shilling, which sounds weird But! You can divide 12 by 2,3,4 and 6 and still be left with a whole number which has many advantages in currency which the decimal system can only handle with clumsy extended decimal places. You could have half of it, a third of it and a quarter of it. Try doing that with the base 10 without needing a calculator. . ( to two decimal places)!

 

Felt, to answer your question, In Gen4 Prius's, the top EV speed without spinning ICE is 84 MPH, but its pretty much useless given the small battery (non prime). I can go up to about 67 or 68MPH for a 1/2 mile holding speed or longer in EV on a downgrade.

 

we use mpg all the time, our European neighbours use l/100km, and various other measures, so when on forums like this it becomes obvious there are so many ways to measure fuel economy

in general 60mpg UK = 50 mpg US as a rough measure, it can be confusing if the poster don't let you know if the figure quoted for mpg is US or imperial / UK, which is why I try to either show mine is UK or give both UK and US figures to help