Unimpressive plug-in Prius results?
Is plugging it in worth it?In "real world" driving, Toyota plug-in Prius testers are achieving about 65 mpg when driving exactly as they would in a conventional Prius.
According to Bill Reinert, Toyota Motor Sales, the way you drive has a far bigger effect on plug-in hybrids compared to conventional hybrid cars. "That difference is just magnified, supercharged, turbocharged with a plug-in electric because how fast you go really pulls the current out of the battery. It is a big deal."
The 2010 Toyota Prius, on the other hand, is supposed to achieve about 50 mpg in real world driving.
Is such a small gain worth the effort?
Obviously, for those with a soft foot, or those whom drive solely in urban traffic, a plug-in Prius might offer significant gains above 65 mpg. So, pricing will be key.
Still, if the new tax credit for plug-in hybrids makes a plug-in Prius the same prices as a non-plug-in Prius, the plug-in version could be a steal.
Labels: Hybrid Vehicles, plug-in hybrid vehicles, toyota prius
posted by Dahcredyns at
8:39 AM
20 Comments:
That's strange, because even A123 conversion achieves 100mpg. Could it be because Toyota uses heavy and less efficient Nickel-Hydrate batteries?
I do not believe those figures. Why would CalCar's advertise 100 mpg if they only got 65?
Where does it advertise? It is not CalCar, IMHO, it is Toyota prototype, or what?
Ford has found the same thing with their plug-in hybrids. Range varies greatly depending upon driving conditions and driving styles.
If you are commuting back and forth to work about 20 miles everyday, you probably will achieve well over 100 mpg, especially if there is lots of stop and go traffic, slow speeds, braking,etc..
If you're going fast, steady speeds, however, the PHEV doesn't offer a lot of advantages, especially if you have a lead foot.
Well, that's true, it all depends on mileage and AC usage. That's obvious. The question is why don't they give statistics split by the average daily mileage.
Well, it doesn't really matter what Toyota says ultimately.
It all comes down to the EPA's city and highway cycles, which aren't really very accurate, especially for measuring extremes, such as tough inner city congestion.
GM, for instance, claims 40 miles of EV power for the Volt based upon the EPA's city cycle. However, in the real world, many battery experts have already claimed the Volt could easily achieve less than 20 miles of EV power.
As hypermilers know, the variance in hybrids is pretty wide, and it will be even wider for PHEVs.
Well, Toyota's plug-in that have been in the testing has the extra NiMH pack installed on the Iconic model (04-09). If that achieved 65 MPG, that's a 19 MPG improvement over 46 MPG 2008 EPA combined number.
The MPG is lower than Google ChargeIT average because it has 2.62 kWh NiMH pack that probably has 1 kWh usable energy (assuming 40% SOC window). A123 System conversions for Google has 5kWh pack with about 3kWh usable energy. Which explains why Google was able to achieve 94 MPG.
If we don't know the the size of the battery pack, the 65 mpg figure doesn't mean anything, IMHO.
Is Toyota trying to badmouth plugin hybrids, make their new Prius look good, or what?
People underestimate their own lead foot. If current hybrids had EV mode enabled, many would see why the range is so short on electric-only plug-ins. I believe the figures. Electric-only travelers would need separate lanes if they were mixed in today because of the impatience of other drivers "off-the-line." It will provide another trigger for road rage.
Research how hyper-milers set their records. They are often coasting at unsafe (slow) speeds.
Like any other of the adjustments to cleaner energy, its not just technology, but habits and culture that face big change hurdles.
alcatholic-
I respect honesty, and using real world results is important (Still your point about batteries is very true. There is too much about this story that is unknown).
Nonetheless, I asked one of the Volt engineers about the Volt and claims that battery life could easily be halved or more depending upon driving conditions.
He admitted that was probably true, but that GM is defining mileage via the EPA's cycles, which even after improvements, are horribly inaccurate, especially in city driving and with hybrids.
Re: Google
Often when test drivers test these kinds of vehicles, they go from city to city. They really try to push these vehicles. So, it's possible that these test vehicles are being driven heavy miles. Under those conditions, 65 mpg is actually quite good.
Contrast that to Google, where most driving is probably short range.
Even the Volt is only going to average about 50 mpg on the highway once plug-in electricity is expired, and that figure is probably based upon optimal driving conditions.
Dahcredyns, if you don't go over 65-70 mph, highway driving is very efficient, especially if it's hot and you have to use AC. I'd tend to think that the only major difference between A123 conversion and Toyota tests is the battery pack. The latter, as it is mentioned above, is heavier and have much less capacity. Lead foot sometimes lead to extreme differences, but lead feet are rare. See, in my opinion, 90% of drivers around me are calmer than I, but I still average 38 mpg in combined city/highway cycle.
LB-
That's true. But the more battery power you have, the better your city fuel economy.
Plug-ins and hybrids don't offer much advantage over other vehicles on the highway. In the city, however, hybrids offer an incredible advantage.
If google is driving about 20 miles between charges, then drivers can use more battery power and less gasoline.
If Toyota's drivers are driving hundreds of miles, then you use much more gas and less battery power.
For trips under 50 miles, the Volt will achieve in excess of 100 mpg. For longer trips, its average fuel economy will be 50 mpg or less.
That's a big difference in fuel economy.
Short distances and city driving are very favorable to hybrids, particularly plug-in hybrids. This factor alone could easily account for the differences between what Google and or A123 claim versus what Toyota claims.
Plug-ins and hybrids don't offer much advantage over other vehicles on the highway. In the city, however, hybrids offer an incredible advantage.
This is a moot point that contradicts to my experience :-) Considering plug-in hybrids, how they can not give an advantage, when electricity price is an equivalent of gasoline price 1-1.5 dollar per gallon? E.g. Tesla claims their electric vehicle to be an 250mpg equivalent.
And if you go cross country in the Tesla?
You can't drive from LA to San Francisco in the Roadster. Well, you can, but it will take you days instead of hours.
You can make the trip in the Volt or a Ford Escape plug-in hybrid in hours.
Moreover, the Roadster costs $100,000. So does its cheaper fueling costs justify that price?
Determining benefits AND costs is critical in such a discussion.
Still, this is more about fuel economy, not energy pricing.
In terms of fuel economy, PHEVs offer the greatest gains on short trips and trips with lots of stops and braking - conditions which increase battery usage.
On the highway, however, the batteries become more of a burden, because of their weight, rather than a help, especially after any 'plug-in energy' has been burned through.
That doesn't mean PHEVs don't provide any gains on the highway, just that their greatest gains and, therefore, their greatest fuel economy is achieved on short city cycles.
You can't drive from LA to San Francisco in the Roadster.
I think you could, if you spend a couple of hours charging batteries in the middle.
However, I cannot agree more: If you have to drive hundreds of miles, the batter can be more of a burden. Especially, if you use a double pack of Ni-Hydrate Prius batteries.
Here's an update on this story. It doesn't necessarily say that 65 mpg isn't true or a possibility, only that Toyota is not providing any official results.
http://blog.toyota.com/2009/02/irvs-sheet-prius-plug-in-mpg-not-yet-available.html
I've been documented CalCars and PHEV's for 5 years now and their PHEV's definitely get 100mpg.
checkout my blog posting that describes San Francisco's endorsement and sponsorship of PHEV's.
http://www.sustainabilitymedia.com/blog/02009/feb/18/san-francisco-plugin-hybrid-electric-vehicle-phev-showcase/
A complete Li-Ion PHEV conversion kit is available right now under $2000 on ebay. You don't need to wait for Prius 2011 or Volt 201X
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200344551230
Many enthusiasts do not want to wait until the release of the official plugin. It is possible to mod your existing car in order to achieve a variety of results.
Why wait? Enginer Plugin Conversion Kit can turn your hybrid into a plugin hybrid in a few hours for under $2000. Source www.eaa-phev.org/wiki/Enginer
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