Consumer Reports on the plug-in Prius

REWahoo

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Consumer Reports has an article in their February issue discussing the results of having a Prius converted to a plug-in version. The aftermarket conversion added a 5KWH lithium-ion battery and almost 200 lbs to the car - and cost almost $11K. On the plus side, gas mileage increased from 42 to 67 mpg in the first 35 miles of driving (before the battery depleted its charge).

Bottom line:

"Our Prius' conversion cost more than you could ever expect to recoup in gas savings"... "But our plug-in Prius showed us this type of technology can produce significant fuel economy gains. And as a sign of things to come, we found it encouraging."
 
How do you get 67 miles per gallon traveling 35 miles when no gas is used in those 35 miles?

How about posting the raw data rather than some flunky journalists half-baked analysis?
 
F_of_A - I assume the engine still needs to kick in for acceleration. I don't think an added 5KW is enough to run in battery-only-mode for 35 miles. But I would like to see the data also.

Their 'bottom line' is confusing to me:

And as a sign of things to come, we found it encouraging."

I think it is discouraging that adding a Lion battery pack to a Prius is not even close to being cost effective. It just demonstrates that we need significant battery cost improvements before this becomes a mass market option. We are a long way off, not on the cusp of conversion to all EV.

-ERD50
 
I read this article, too, and as a subscriber, I think they wasted $11K.
 
Their 'bottom line' is confusing to me:

And as a sign of things to come, we found it encouraging."

I think it is discouraging that adding a Lion battery pack to a Prius is not even close to being cost effective. It just demonstrates that we need significant battery cost improvements before this becomes a mass market option. We are a long way off, not on the cusp of conversion to all EV.

-ERD50

Agreed. I subscribe to CR and read the article. When they said that you'll never recoup your $11k investment, that was a HUGE understatement. In fact, you'll never even come close to recouping your $11k investment. CR, with the help of Argonne National Lab calculated the savings per mile for fuel (gasoline @ $4 + recharging electricity @11 cents per Kwh) would be 2 cents. $10,875 coversion cost / $.02 = 543,750 miles to break even....... And that is the best case assuming you don't need a new battery during that time or that the extra do-dads added to your car cause no reliability problems, extra repairs, etc. And, oh yeah, don't drive over 35 miles without a recharge or the breakeven point skyrockets upward.........

You're right, if this example of plug-in technology is as good as it gets, we need some big breakthroughs if we're ever going to make it pay, especially if you drive over 35 miles without recharging very often.


Standard Prius: 42 mpg overall, 34 city, 47 highway

Plug-in with battery charged: 67 mpg overall, 56 city, 75 highway (approx the first 35 miles)

Plug-in battery depleted: 40 mpg overall, 29 city, 47 highway
 
The pack doesn't take over completely. The car still runs on gas with a battery assist.
This particular pack (if they are using the Hymotion pack), is largely dependent on your commute.
If you drive 75 miles on a highway, you will get 60-70mpg (I am guessing this is what they did, any details??).
If you have a 10 mile commute between charges, you will get closer to 125mpg.
If you drive in cold climates, the batteries will not be as efficient.
Basically their conclusion is correct. It is NOT yet cost effective, of course, neither is a sunroof, or for that matter, a new car in most cases.
And as the battery technology improves, it will become more effective for more people.
 
If you have a 10 mile commute between charges, you will get closer to 125mpg.
.

They did not achieve this. See the info in my post above taken from the article. They said "While the converted Prius operates the electric motor and gas engine as needed, as in a standard Prius, it spends more time running on electricity and relies less on gas. Still, when running solely on electricity, any moderate acceleration or mild grade makes the gas engine kick in." Perhaps if the driver was extremely light footed and never encountered an uphill grade, results closer to your 125 mpg might be possible. But not on the standard CR course where they do all their milage testing.
 
I did, they stated 35 miles, not 10, and there were no details about the type of drive or weather conditions.
I have gotten that mileage myself, in summer, when going under 10 miles each way with a charge in the middle.
However, I rarely drive that way, so my overall mileage is much less.
 
When they said that you'll never recoup your $11k investment, that was a HUGE understatement. In fact, you'll never even come close to recouping your $11k investment. CR, with the help of Argonne National Lab calculated the savings per mile for fuel (gasoline @ $4 + recharging electricity @11 cents per Kwh) would be 2 cents. $10,875 coversion cost / $.02 = 543,750 miles to break even....... .

Yup, and this also ignores the time value of money, as many of these break-even calculations do.
 
Yup, and this also ignores the time value of money, as many of these break-even calculations do.


That's a good point. In this case, driving the half million plus miles to reach breakeven would take me 30+ years. The time value of money is very significant over that kind of span. And who knows what could happen to the car over that time, what new technologies would appear making your plug-in Prius obsolete or where energy prices will be?

Having said all that, my hat is off to folks investing in this type of technology because they are, in a small way, helping to advance the research and technology. I'm sure they understand they aren't saving money.
 
Also read the same Consumer Reports Article.

IN my local newspaper, "Road show section", (about car things), A person complained it cost almost $ 900 to replace 2 burned out headlights!

Labor was $ 200. This number sounded crazy until other writer's verified they had similar cost's replacing the Pirus headlights.

Happy new year.
 
IN my local newspaper, "Road show section", (about car things), A person complained it cost almost $ 900 to replace 2 burned out headlights!

Labor was $ 200. This number sounded crazy until other writer's verified they had similar cost's replacing the Pirus headlights.

It's not hard to do, if you have small hands. I'd suggest replacing both lamps at the same time. The process takes maybe an hour on a 2005. You need to remove a plastic dust cover on the front of the engine under the hood, and either the top of a fuse box, or an air duct, to get access to the back of the headlamp. The bulbs are in a funky bayonet fitting that has to be turned and wiggled just right to release, and is finicky to re-install.

I haven't tried this, but the 2008 Prius manual has the procedure as:
Code:
Remove fender well trim ( a few screws)
Remove front bumper COVER (not the bumper- the plastic cover)
About 14 screws. Mostly on the underside, get a creeper, and a few
on the top.

Remove the (left or right side) Headlight assembly ( a couple more screws).
One assembly contains the headlight, turn signal and running light. Unplug
the electrical connector from the assembly. All bulbs remove from the back
of the headlight assembly. Headlight is held in place by bail wire, smaller
bulbs are 1/4 turn.
 
I haven't tried this, but the 2008 Prius manual has the procedure as:
Code:
Remove fender well trim ( a few screws)
Remove front bumper COVER (not the bumper- the plastic cover)
About 14 screws. Mostly on the underside, get a creeper, and a few
on the top.

Remove the (left or right side) Headlight assembly ( a couple more screws).
One assembly contains the headlight, turn signal and running light. Unplug
the electrical connector from the assembly. All bulbs remove from the back
of the headlight assembly. Headlight is held in place by bail wire, smaller
bulbs are 1/4 turn.

On my celica you flip up the lights, There's one screw on the exposed side with no obstructions to keep you from accessing it. When that screw is removed you unplug the headlight and plug in a new one. I replaced both headlights in under 3 minutes last year.
 
Remove fender well trim ( a few screws)
Remove front bumper COVER (not the bumper- the plastic cover)
About 14 screws. Mostly on the underside, get a creeper, and a few
on the top.

No Thanks! Changing a light bulb should be as easy as..... changing a light bulb!

On my celica you flip up the lights, There's one screw on the exposed side with no obstructions to keep you from accessing it. When that screw is removed you unplug the headlight and plug in a new one. I replaced both headlights in under 3 minutes last year.

I have heard of a few other cars where the headlights are a major job to replace, costs hundreds to have the dealer do it. My Volvo S40 is tricky, it's mostly a blind operation, and you have to get the bulb base seated *just* *right* or the clips just won't go into place. But you don't need to remove anything, and after you've done it once, you might get lucky and get it done in a minute, but five minutes is probably more like it.

I need to remember this on my next car purchase. It would kill me to think that a simple DIY thing like changing a head light bulb could cost hundreds, or take more than few minutes of effort. Is there a web site that lists crazy stuff like this on a model-by-model basis?

-ERD50
 
Hmmm, my 1985 CRX Si got 50 mpg - approximately 10 gallon tank and could drive 500 miles before empty....could get from Phx to LA on one tank.

I drove the Prius as a rental in SFO a few weeks ago - was not impressed with the mileage, frankly - the display showing the powertrain connections and what was powering what was cool, though.
 
This makes me wonder once again if GM still doesn't get it with their Volt, last reported with a price target of under $40K. Unless they have technology that no one else has, and it certainly doesn't sound like it, the Volt may be another money pit for them. They talk as if it's their future, but it looks like another miscalculation on their part. I hope I am wrong...
 
It may be a few years before the PHEV become economically feasible for most consumers. I have not doubt that more experience and R&D into PHEV will yield progress.

If the USA winds up just using smaller conventional gas vehicle (on average) or more conventional Hybrids (like the current Prius)... we will reduce oil consumption consumption.

I suspect that the next vehicle that we purchase ( 4 or 5 years ) will be a hybrid of some sort.

It will be interesting to find out how rapidly progress is made. If progress is made quickly with leaps and bounds... It might make sense to lease. For example, if prices continue to drop, or if there is significant risk with early technologies... leasing may be a better option. It could mitigate the risk of buying a poor design or if prices decrease.... of course it depends on the residual value of the vehicle.
 
It''s not easy to find info, and the U.S. figures are likely different, but the average distance for a car trip in Sydney Australia is less than 11 kilometres. A small electric car dedicated to this sort of trip would likely be incredibly economical.

Haven't read the article, be nice if CR did a study based on the most common car usage.
 
Interesting threads about the Prius and the mileage its gets, then upgrading it to a plug-in and how the cost can't be justified. Lets go back to the original cost of the Prius. I understand the cost of the hybrid is $4000 over the standard car. At 40 mpg and gas at $4/gal you would have to save 1000 gal of fuel to break even on the hybrid. Gas at $2/gal you have to save 2000 gal. That's a lot of gas. I don't think anyone really buys a Prius just to save fuel. It's a mindset. I have a little Ford Escort 5-speed (1998 model) -purchased used for $1800 that gets 30 mpg. Thats getting a payback.
 
We're sort of between a rock and a hard place with this stuff. Right now it's not economically feasible to mass produce this stuff pending more (costly) R&D on battery technology and production facilities... but if we wait until it becomes obviously cost effective, we'll be screwed for several years waiting for it to hit the market.
 
This makes me wonder once again if GM still doesn't get it with their Volt,

... They talk as if it's their future, but it looks like another miscalculation on their part. I hope I am wrong...

And the (not so) 'funny' part of this is that the govt and the greenies are talking like the VOLT is *the* future. Just because they like the sound of 'plug in hybrid', but they ignore the facts of cost, plus - we don't know what the price of gas will be in two years. It may gain a loyal following, but it is not going to be mainstream at those prices.

It''s not easy to find info, and the U.S. figures are likely different, but the average distance for a car trip in Sydney Australia is less than 11 kilometres. A small electric car dedicated to this sort of trip would likely be incredibly economical.

Haven't read the article, be nice if CR did a study based on the most common car usage.

But that is a bit misleading - kind of like the old joke about the 6 foot tall statistician that drowned in a pool with an average depth of 5 feet.

When you need to take that longer drive, and can't use that electric vehicle, it lowers the value of it for you. Some people will have access to another vehicle, but either way, the utility value of that electric is reduced if you can't use it the same as other vehicles.

edit/add - and another thing - with present battery technology, an all-electric vehicle of limited range will *not* be a cheaper car to buy. There is a relationship between the power you need for decent acceleration, and the power you need for extended range. Right now, if you have enough battery power for decent performance, you also have enough for decent (short commute) range. If you do the math on the VOLT - that is exactly why the range is 40 miles, not because they shot for that as a goal, it is what you get when you have enough batteries for decent performance. Same with the Tesla - when you get 200 mile range, you also have enough burst power for 4 second 0-60 times, and a small group of people will pay $100,000 for that.


I think people are forgetting that any hybrid is a stop gap, band-aid type measure. If you need to carry an engine around with you in your electric vehicle, that is added weight and that is a negative factor for total energy use, space usage, cost, and complexity. It is what we need for the next few years to get the range we want, but a full EV has to be the goal for these vehicles.

I've said it before - hybrid technology makes a heck of a lot more sense for high usage, stop-and-go vehicles like delivery trucks, busses, taxis, mail trucks, etc. Yet, we have not seen wide scale adoption right where it could have the highest payback - why is that?

-ERD50
 
And the (not so) 'funny' part of this is that the govt and the greenies are talking like the VOLT is *the* future. Just because they like the sound of 'plug in hybrid', but they ignore the facts of cost, plus - we don't know what the price of gas will be in two years. It may gain a loyal following, but it is not going to be mainstream at those prices.
Well, I think PHEVs are likely to be one critical phase of the future. But the first hurdle is creating a suitable battery for shorter trips that is cost-effective and competitive with existing mainstream automotive technologies.

At that point I think the PHEV will be the bridge between the traditional gas-powered engine and pure electrics. The latter can't become too relevant until they can get more than 50 miles in a charge and they can (at least mostly) recharge with an amount of time not much longer than it takes to fill a gas tank.
 
Somewhere along the line, the issue of generating enough electricity to keep a fleet of millions of electric cars charged inexpensively and without pollution has to be brought up......

Imagine LA on a hot August afternoon. Brown-outs are threatening due to high air conditioner use. Then, 335,986 folks plug in their electric cars to charge. :p
 
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