Consumer Reports gets only 67 mpg with Hymotion Prius

Stuff like this is exactly why I don't explicitly trust Consumer Reports. I take them with a grain of salt just like any other info.

 

I bought the "Consumer Reports Cars Best & Worst for '09" a review of "268" models. From this and analysis of their January 2009 issue, I realized:

• handling heavily weighted - Consumer Reports has a handling protocol and this has a high weighting in their vehicle evaluation. This includes stopping as well as avoidance manouvers. Remember the 'stiffener plate?' That is the type of after market product that would correct a weakness in handling that Consumer Reports is likely to detect.
• electronic stability control - is very highly rated in Consumer Reports and they marked the Prius down because they believe it to be an option, not mandatory. It doesn't matter if 95% of all Prius are sold with electronic stability control, Consumer Reports will downgrade the vehicle. Also, the Prius came in only 4-stars in rear passenger safety, another negative in their safety rating system.

I am not defending their standard but rather trying to point out this seems to be why their ratings for the Prius look weak in some areas. With luck, the 3d generation will stiffen the frame so stiffening plates are no longer needed and make electronic stability control standard. Perhaps side, rear air bags might improve accident performance.

Bob Wilson

 

My guess is they had the Prius cold outside temperature of 10 F on the interstate doing about 75 MPH. That's about the only way the Prius with Hymotion will get those results. I would like to see the test data to be able to comment to the editor.

---Kent

 

The article is here. They do note

Their test cycle is described here

 

I was shown this article by my aunt who's subscribes to consumer reports. I found it very discomforting and shows a lack of understanding of the car and its abilities by the reporter. If you want to go as far to say they are closed-minded and uninformed of the world, I might agree; however they are just another corporate giant out to make $. My only real complaint about them is that you must consider their "Reports" with a grain of salt, their only 1 opinion amongst a ocean of opinions out there about any consumer products.

 

Over several years consumer reports has shown to be a biased publication not worthy of trust to evaluate a product in an informed way. This report on the Hymotion is just the most recent example of this.

 

Is there another publication that has been more fair than Consumer Reports? I may not always like the outcome of their tests but I have a hard time faulting their methodology.

If there is something about our hybrids that make them appear to perform poorly in the Consumer Reports test, the right answer is to 'fix the hybrid.' This in turn makes the fix available to a wider range of lay-drivers who are also ignorant of the subtle aspects of peak performance.

We are in the 1915s-1920s of hybrid vehicle performance. We've seen two of three generations of Prius in the USA (the first never arrived.) There is a necessary learning curve on how to integrate the hybrid control laws and designs with how people actually drive. Let the machine do it so even my non-technical wife can get good mileage. <wink>

I just wish I knew their highway mileage route. I could then see if there is some way to replicate it in Alabama.

Bob Wilson

 

I have a very high opinion of CU. I think they are the most unbiased testing organization out there. PeakOil feels that driving the car like a "newbie idiot" is false advertising, but remember that CU is a publication for the ordinary consumer, not the skilled aficionado, and that they test all their cars under the same standards.

What I find noteworthy, and I doubt anybody can find fault with, is their finding that while the HyMotion conversion yields significant increase in mpg while the additional battery has charge, its added weight reduces the mpg after that period. In other words, this PHEV out-performs the stock Prius for short commutes, but under-performs the stock Prius for road trips. Once the lithium battery is depleted, it does not participate in HSD operation, and is not available to recuperate the energy of long downhills, for example. Presumably a PHEV from Toyota will change this.

A Prius-savvy hyper-miler will get much better mpg numbers, and stretch the PHEV range beyond what the CU protocol achieves, but will still see a reduction in FE after the battery is depleted, compared with what s/he achieves with a stock Prius. This tells me that in my case, a HyMotion conversion would be a bad idea, since I only use my Prius for longer trips.

 

Another article on this (that I stumbled across today) "Consumer Reports: Prius Plug-In Kit Gets Nowhere Near Maker's 100+ MPG Claim" Green Car Advisor. At least you can comment there...

 

http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf doesn't have the route but says:

 

These folks have a plug in fleet

Google.org

They subject the cars to 'average skill' driving (I guess), and average 57.6 mpg.

 

I have a hard time believing that 187 lbs will result in a 5 mpg decrease in city driving.

 

Funny how so many of us read the same article, and came away with vastly different impressions. I thought "about twice the mpg with the hymotion upgrade than without. Yep, about what I expected."

Since I average about 70 mpg in my Prius in temperate weather, I would expect about 150 with the hymotion upgrade. I no more expect to get *their* driver's 67 mpg with the extra battery, than I get 34 mpg without it.

 

I just had the Hymotion installed three days ago by the Green Car Co. of Bellevue, WA. in a 2007 Prius. Based on my limited experience, I neither see how I will ever achieve 100+ mpg as advertised, nor do I see how CR got only 67 (unless they drove most of the time with the battery depleted.) I am averaging 82 mpg -- with fairly careful driving but not really hypermiling.

I commute about 25 miles per day and so far the battery pack has depleted several miles before I reach home each day -- maybe I am getting about 20 miles out of it. I would say that is probably my biggest disappointment. (The 82 average includes those miles with the battery shut down.)

I should note I have been driving in 30-degree weather, the car is parked outside and so is started in the cold, and the manual warns that ambient temperature has an effect, perhaps a large one. Under these conditions the gas engine doesn't really shut down until I am about 7 miles into my commute into town. Anyway, wait 'til summer to find out.

Another consideration -- I have non-stock Toyo Tourevo "touring tires" designed for better traction and, especially, for noise reduction. They are one size larger (195). I LOVE how much better this car drives on those tires but I did notice they cut mileage a bit --maybe 2 mpg.

Anyway, thought I pass it on.

 

With the cold we've been having in the NW this past week or so I'm sure it's having a huge effect on your battery performance and thus overall mileage. I'm actually impressed at the numbers you are getting. Maybe add an engine block heater? Grill fully blocked?
Temperature here this morning was 13F, glad my car sleeps in the garage!

- D

 

Consumer Reports has a pitiful record for fuel economy. The Force just set a new record and beat Consumer Reports by almost 2700 MPG!

The New Record!

 

Is there somewhere I can find and read up see picture of this prius that never made it to the USA I'm curious to see.

 

i do value CR to a point. they have always tested their cars on more of a stressed level than most of us would drive our cars, so i fully expect their test mileage to suck...it always does.

but to get 67 mpg actually says volumes. there is no doubt they tried to make it less and couldnt do it...lol awesome!@!

 

With our cold snap and my Prius huddled overnight (as low as 7 degrees) there may be another reason my new Hymotion pack was yielding just 20 miles... brownout conditions. My neighborhood has been suffering brown lights, slow microwave and long oven cooking times, etc.
Puget Power came out and did a little fixing on the lines and improved the neighborhood voltage so now it is just a couple volts below normal. (It should get better as usage lets up with normal temps.)

Suddenly I am getting about 24 miles out of the battery pack.
Is there a connection? Does a lower voltage (despite ample plug-in time) keep the pack from getting its full oomph? (Although the SOC screen hasn't shown any reduction.)

Something to think about, anyway.