NEXT GEN VOLT

I think 2 of the 3 you list are a must to gain wider acceptance - interior room at least needs to be better packaged and the price needs to be more competitive.

 

I'd most like for future battery improvements to be compatible with the cars already on the road. I am envisioning a pack of the same size, but more capacity and perhaps less weight that can be used in the next gen volts but also swapped out for the old packs in the first gen volts.

 

Better batteries/EV range would be one. Although don't need much, say another 10 miles.
Have no need for more interior space although it wouldn't be a detriment if it had a little more back seat legroom.
Lower cost is always nice for any vehicle as long as it isn't to the detriment of other features.

 

<delete> after seeing it is DBs thread.

 

lower price, better efficiency (both electricity and gasoline). why guzzle both?

 

No ice

-Htc Tapatalk

 

Seating for five
Engine that runs on 87 octane. Maybe trade performance for better economy
Longer EV range (of course)
Reliability, reliability, reliability

 

Wow, they just released some info on the 2013 Volt.
EPA EV range increased from 35 to 38. Excellent news although I would still like to see another 7 to 12 miles on the range.

 

Lower price, even if that means lower range. More efficient gas engine will negate/relief that. That should also enable the 5th seat with smaller battery.

The bottom line, put the existing components to more use. Get rid of the EV purity notion and promote the teamwork of the hybrid powertrain. The Hold button for the 2013 Volt is a good start.

 

That's exactly what was meant by "too little, too slowly".

We all knew the needed components were present, but the chosen configuration didn't match what mainstream consumers required.

Purity is a low priority for middle-market. They will benefit greatly from a significant reduction, which is what the hybrid system could deliver.

 

I would like to see a blended mode that more uses the gas engine when I know I am going to travel long distances. Perhaps then it could do a bit better on the overall mpg? Perhaps the gas engine is more efficient to be used? Oddly though they claim that it needs to be over 70mph for it to be more efficient. Basically I would like to see some performance curves of the different theoretical operating situations. I believe the higher octane has several advantages. It keeps better and many Volt owners I know usually see the engine maintenance mode so they need that. More battery capacity would be awesome! I want a backup though, because I can't have 2 cars but I want to drive EV here and have the ability to drive cross country. I feel though that even having a really small engine like 50hp at the most, even smaller possibly could be utilized. You would have to let your car know you were going to be traveling great distances though, because even with a fully charged battery, with that limited generation you would have to immediately start charging. Perhaps the computer could tell you how far you could drive at various speeds the same way it calculates it's range. That would be neat to see!

 

Not sure where you got the 70mph is better.. When the volt is is mode 3 (ICE+EV in parallel-hybrid mode) is the most efficient mode for the ICE, which can occur anytime from 35-??mph (the upper end depends on road load and wind.. more than just speed). The car has to decide its not accelerating, or it waits to change to two-motor ER (mode 3). Because the areo-drag increases quadratically with speed, its most efficient as on gas as long as you can keep it in two-motor ER mode. (Well 2-motor EV might be more efficient, but its only avaible at very high-speed and low-load, like downhill at 75mph).

Here are some chart's showing the various modes for speedsvs tourque.


Here is a related plot.. the KWH/mile consumed for the Volt at various speeds (measured by user)
http://gm-volt.com/forum/attachment.php?attachmentid=2242&d=1309465048

 

Thank you! I had heard from almost every source possible that Volt engine came on only as a "generator" to extend the range. The gasoline engine is only supposedly coupled onto the drivetrain at speeds of 70mph+ because the engineers said that it was more efficient at that point. A lot of people complained as the drivetrain was supposed to be 100% EV and the engine was only for generating electricity. There is supposedly a "3rd clutch" or whatever to keep it disconnected from providing torque to the drivetrain until those conditions are met. Have I heard wrong?

 

yup what you heard is wrong. It can be a serial hybrid (i.e. using engine for generator) but as you can see from the above chart (figue 18 from a GM paper), two-motor ER driving can occur from about 60 kph (about 35mph) anywhere up to 100mph. the two-motor ER (i.e. parallel-hybrid) mode is 10-15% more efficient than serial hybrid in the range were it is used.


There is nice video on youtube about it.

In that video around 33:40-34:30 they show extened range driving and shifting from 1 motor serial hybrid mode, accelerating to 70, then settling at 70, the clutches changing and the car switches to two-motor ER mode. I think that is where the magic 70 came from, but its was just an example speed.

If you want to understand how the volt really works, I recommend the whole 40m video.

 

I'm going to double check. Because I was hearing this 70mph number directly from posts by Volt engineers. This video seems to date back before the actual production model hit the market. However, it is after their first release that it wouldn't always be a "true serial hybrid." Never fear, I'm not upset or offended. Efficient is ALWAYS better! I appreciate the video, I always wanted to visualize how the Volt's drivetrain functioned and never did come across this video. Much like this link for the Prius: Toyota Prius - Power Split Device

 

Well if you can point to the article's I'll examine it. There are articles like this one from motortrend

Unbolting the Chevy Volt to See How it Ticks - Motor Trend


That also get the 70mph wrong.. (but I think they got it from the example in the video, as the figures look just like segments of the video.


It is also possible its from a map such as these


which show composite engine efficiency as a function of torque and speed. But the torque there is dyno-torque so its ignoring wind resistance, which grows quadratically with speed. So while there is a region of 87 at around 70mph, its only going to achieve that if you are only using 300nm, which at 70mph means you are going downhill or have a stiff tail-wind. Comparing with figure 18 above you'll see its also about where 2-EV serial mode can happen (which is why i made that comment before.. i presumed that was in the 2EV mode.. but maybe its still 2-motor ER).

 

Motor Trend did indeed publish 70mph from there testing. At that point gm was mum, but later clarified that it can happen at lower speeds. I don't think they ever gave a full statement on what torque/speed transition will occur.

 

Well I shall continue to look into it and get back to you. I know I saw speeds of over 69 or 70mph somewhere. And in this video they answer questions on the presentation. They said there was no "direct" mechanical linkage. Knowing what I know about the Prius, that's sort of a funny way to put it because really there is... but I think it happens more as a passive leaching of the power since it's already producing anyway. She did say it had to be "high speed situations" but then again that's not definitive. It's kind of open ended. I will check back later on when I can do some research!