2011 Chevrolet Volt gets an EPA certified rating of 93 MPGe and 37 mpg in gasoline mode

I remember when people thought it would get better gasoline mode ratings than Prius

 

You're about a week late to the party:

http://priuschat.com/forums/prius-h...-electric-37-mpg-gas-only-60mpg-combined.html

 

Remember this is the Gen1 Volt with an Otto cycle engine, which had to use because they only had enough time to pick an existing unit off the shelf.

When they switch to an Atkinson (or Miller) cycle engine, like the Prius, the gasoline only mpg will increase immediately by around 25%. The use of the Atkinson cycle is by far and away the major reason the Prius gets good mileage, simply because it extracts about 25% more energy from every gallon of gasoline than an equivalent Otto cycle engine (ie 36% instead of just 27% thermal efficiency). I would expect the Gen2 to appear with this modification (and a cheaper, lighter battery) in 3 years time.

 

GM had time to reverse engineer the Prius to death, and they came up with the Volt? It's smaller, heavier, and you can tell it has some "GM quirks" about the styling from their previous generation of cars. It's total range of electric plus gas powertrain is in the mid-300's mile range, and it's engine requires premium gas when supposedly it doesn't directly power the drive wheel (which we now know is not entirely true). My 50+mpg Pruis that let's me go almost 600 miles per tank is the better alternative, more practical, roomier, has a lower overall initial and long term cost, and most likely more reliable. I am disappointed that GM came out with the Malibu and LaCrosse, but don't seem to have the same type of hit in the Volt. I hope it succeeds, but let's see how the general public will warm up to it.

 

And power will immediately drop.

The actual reason they abandoned the original 3-cylinder 1.0 liter (which then already had available from Metro) was to increase power.
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Power in the Volt is buffered by the battery, so there would be no issues with switching to Atkinson cycle, just as with the Prius.

The whole reason Prius is a hybrid is because Toyota realised (like everyone else) that although using an Atkinson cycle engine would dramatically increase mpg, it would also result in a vehicle being much less driveable, particularly in terms of lack of low-end torque, poor idling and poor throttle response.

They realised the only way to bypass these problems was to add some kind of power buffer, and a battery was chosen as the solution. It's why Ford uses the same setup for its hybrids.

 

Volt's PSD is different than how Toyota and Ford hybrids are setup. Volt's ICE rpm appears to be tied with speed (per Motortrend graph).

Here is my brief thought on this. HSD provides CVT to the ICE by varying the generator rpm. Voltec provides CVT to the traction motor by varying the second motor rpm. It provided 1-2 more EV miles by lowering the traction motor rpm. There is a catch of course. The catch is, you lose CVT between ICE and the wheels. ICE rpm is now tied to the wheel speed (once it is clutched in). We don't know if the throttle response of the Atkinson cycle is viable for the Volt.

In addition, Atkinson cycle engine has different sound, especially above 3,000 rpm. I believe Volt's ICE operate around 4,000 rpm so it will be quite annoying.

Atkinson cycle improves fuel economy due to higher thermal efficiency. It also lowers emission, not only CO2 but also NOx, CO, PM and other tailpipe emission.

 

I am afraid 10 MPG more than the Prius is not enough incentive to plug it in and pay extra in electricity.

 

Yes, but you could drive 14,600 miles per year in a Volt without using any gasoline if you wanted to. Some people will like the idea of reducing reliance on foreign oil.

 

At the moment I think most of the inferior energy economy of the Volt compared to the Prius can be explained by the ICE choices and extra weight. The extra weight is not going away, because it is spent on battery and "driver experience."

GM cannot out Prius the Prius engineering wise, so they took a marketing tactic of selling an energy hog with some higher end features that can run on electric. Works for some, I guess.

 

Thanks for this Dennis. Explains quite a lot.

 

Yes, but Leaf would make a better choice for it. Less expensive, roomier and more range.

 

More range anxiety though!

Volt is supposed to be a happy medium. Enough EV range to cope with the daily commute, but then a gasoline range extender so you can drive across country in the same car. With the Leaf you would have to buy a second car to do that, and that could be quite expensive!

 

With the Volt, there is range extender anxiety -- ULEV gas engine that runs on premium gas and MPG is less than the assist hybrids from Honda.

Most of the Leaf buyers should have a gas car already (probably mostly Priuses).

 

I would buy a leaf tomorrow if...

1.) My Prius was fixed. Still awaiting repairs from dog strike.
2.) I had the money for the Leaf.

Prius would be my gas guzzler; I would drive Leaf to work (about 45 miles round trip) and for shopping at night, whatever. Plug it in before bed and start all over the next day.
This all depends on good reviews of the Leaf for "driver experence" and range.
:focus:

 

My family has two cars, and it will stay that way if my work stays the same. Right now that means a Prius and and old ICE Subaru, but I anticipate it becoming an EV along with our Prius. EV for daily driving fueled by personal PV, and the Prius for my ~ periodic long drives.

My fingers are crossed that I get my PV. Bloody neighborhood covenants.

 

The Volt has a knock sensor, so it can run on regular. Granted, using regular may reduce fuel economy, but likely not enough that sticking with premium would have a financial advantage. That goes for the times you take the car out for a road trip. If most of the driving is with electric, just use premium, it has a longer shelf life. It's just 2 to 4 dollars more a fill up with no hassle of measuring and adding a fuel stabilizer. So you skip Whopper Wednesday that week.

It got an ULEV II rating only because of carbon monoxide emissions. It would have been SULEV II otherwise. It is GM's first generation hybrid in which they cared about emissions. There are likely variables involved in a hybrid that don't even have consideration in a standard ICE car. The first Insight wouldn't score as well under current emission standards, and the gen 1 Prius might not either.

Bringing up 10 year old models isn't an apples to apples comparison. Well, if GM hadn't been run by a bunch of egotistical idiots, we might be discussing the 2nd gen Volt now. I am apathetic towards GM. The only car of theirs that I have driven and liked was my '86 Park Ave.

I just would like to see the Volt judged on it's own merits. I've mostly seen arguments used against it here that would have been defended against if , and when, used against hybrids and EVs in general. It doesn't live up to GM's promises. Duh, it's GM, we already know they lie. I'm personally disappointed in the direct connection between the wheels and engine. That's only because it makes converting a used one to pure EV harder. Otherwise the designers and engineers seem to have done a good job of trying to meet expectations.

Outside of enclosed spaces, does CO have a negative environmental impact? Difficulty of committing suicide with isn't one of my car shopping criteria.

Would have liked to see higher fuel economy. However, on a long road trip it does about as well as the Honda hybrids. So the Prius has a longer range on a full tank. So what? How often do people jump in their car, and drive for 500 miles without stopping at all? Unless you are planning to trek across the Sahara, and I would take neither one, maximum range isn't important. I'd have been happy with a smaller tank in the Volt. An Audi PHEV prototype only has a three gallon tank, and a slightly shorter EV range than the Volt.

If the Volt's electric range is long enough for most people to use little to no gas, then I have no complaint about it. It is a half to a third of full EVs that are coming out in the near future. It may not be as efficient in electric as a pure EV, but that's the price of peace of mind. And that's the Volt's real advantage. An EV would be a better choice for nearly everyone buying a Volt. But we are dealing with people, emotional beings that are mostly nuts. Most aren't ready for the shift in thinking required for owning an EV. Some will never be. The Volt is for them, and it will help make a pure EV more acceptable for their next vehicle.

 

Knock 12 to 15k off the sticker price and it might be worth what it offers. As it is, it's out of the range of customers who could take advantage of it, and of little interest to customers who could afford it!