Consumer Reports Rating of 2010 Prius

well cant say that i hate CR. was a subscriber up until a few years ago when i decided to stop receiving paper in the mail as much as possible is when i terminated my sub with them and others.

i have actually been a fan of theirs for years and on the one hand, i can see how city driving has a huge variance so test track makes sense. but at the same time, under 3 minute segments are unrealistic and penalize the Prius more than others due to its warmup cycle. granted all cars need to warm up. but the Prius does not warm up while sitting at a light like a regular car does so the comparison is not valid.

what they should do is at least do the entire track which must take more time since it involves 4 minutes of waiting which again is not realistic for 18 stops. even at 30 seconds per stop that would imply 8 lights, 10 stop sign?? again, not realistic.

one thing that puzzles me somewhat, is that CR has always been consumer-driven. there have been many reviews that readers took offense to. CR took the feedback, examined it and their processes and usually came back with a reasonable compromise. on this drive test thing, they have defended their processes adamantly despite the large discrepancies.

 

I, for one, am glad that SOMEBODY is getting lower city driving mileage than me! Right now, because of fairly short daily commutes (4-5 miles each way), hills, and many stop signs and red lights, I've only been getting around 42-45mpg at fill-ups. My average mph is only 15! If I were going to the closer Metro station, which is only a mile away instead of 4 or 5 miles, I'd probably be averaging around 32mpg because my first 5 minutes or so is really dismal. And this isn't because of lack of effort on my part.

I don't know why everyone is getting so upset with CR just because they don't reflect people's driving experience here. As far as I know, they still rate the Prius #1 as far as gas mileage goes! Also, this forum is not representative of everyone. Most people do not keep detailed statistics at every fill-up and probably have no real knowledge of what they are getting.

 

I get much lower mpg (apparently the low 40's) "around town" (hilly surburbia), with little real "city" driving.

On the freeway, I get mpg in the high 50's over 74 miles.

 

It is hard to believe some of the comments I read here knocking CR because some folks don't like the results of their Prius review.
I read the report and they used the same criteria to review the Prius as they do for all the other cars.

I guess I haven't drunk enough of the Prius kool-aid yet. I thought CR was fair and honest in their report and agree there are still quite a few areas where the Prius could be improved. That being said, I still love my Prius and CR.

 

in my case, other than my Zenn, i have not driven another type of car in over 5 years so cant really comment on another car. they posted stats on a many cars and they all have the same lower city ratings. so its not bashing the Prius review, its bashing the testing method.

someone posted that they get poor city mileage because they only drive 4 miles and spend like 10 minutes to do it and getting 42-45 mpg. well, that is nearly 4 test runs for CR. shorten your runs to 3 minutes and you will also be getting 32 mpg.

 

I guess my point is the testing method (criteria), liked or disliked, are the same criteria applied to all vehicles tested. I don't believe the tests would be relevant if CR created a separate set of testing criteria for just the Prius to better shows its strong points.

Maybe the Chevrolet Malibu owners are saying the same thing - the test methods are flawed.

From my observation, many Prius drivers do drive their cars like any other car and are not driving in a way that necessarily optimizes fuel efficiency.

 

My Milegae experience Re: Consumer Reports Rating of 2010 Prius

Given that consumer reports does a 4 mile test track, and the first 1 to 1-1/2 mile is warmup, my experience is that warmup phase consumes 0.05 gallons. That is in addition to the normal consumption -- lets say there mileage was 50...they would consume 4/40+.05=.13 gallons in 4 miles. That would be 31 miles per gallon over the four mile loop.

That is not a surprising result...If they started warm, they you beat 50 MPG.

This test is actually good, because it shows shortcomming of the Prius in the short trip to the grocery store.

 

Re: My Milegae experience Re: Consumer Reports Rating of 2010 Prius

Agreed!

 

For grins, I looked up the EPA ratings for these four models and plotted them with the CR results:


Now this was just a quick grab of four data points, non-hybrids, just to get an idea of the relative numbers between Consumer Reports and the EPA tests:

• similar offset on City testing - the nearly identical slope suggests the range of City numbers will be fairly consistent regardless of test protocol. The CR numbers are consistently lower but that may not be such a bad thing, especially for folks who live in northern latitudes.
• wider variation on Highway testing - CR is coming closer to the older, EPA numbers. But the variation compared to the EPA testing has me scratching my head. This could be the effect of having to conduct tests on the road in a temperate climate versus the EPA protocol that is dynamometer based.

Now I prefer having 'mph vs MPG' and 'hill climb' graphs over the two number, City/Highway, metric. We could have added the Euro and Japanese metrics for equivalent vehicles and we would have four pairs ... five pairs if we roll the clock back before 2008 and use the old EPA test numbers:

1. City/Highway - Consumer Reports
2. City/Highway - New EPA
3. City/Highway - pre-2008 EPA
4. Urban/Extra-Urban - Euro testing
5. City/Highway - Japanese testing

The problem with these two number systems is they don't help the driver choose driving patterns that maximize their fuel efficiency by selecting routes and speeds that minimize their trip durations. For example, the two number systems don't identify the 'knee in the curve:'


A proper study would collect a large set of Consumer Reports test numbers and compare them to the EPA numbers (and Euro and Japanese tests.) This was just a snapshot of data 'cwerdna' provided just to get a clue. But we're still looking at the problem of two number systems that don't give the information needed to drive efficiently after the purchase.

Bob Wilson

 

Re: My Milegae experience Re: Consumer Reports Rating of 2010 Prius

I haven't done a detailed analysis but this number seems reasonable based upon earlier tests with my 1.5L Prius. One aspect I can't measure, yet, is the traction battery overhead since I often use EV, normally speed triggered, in the final mile to the house. This brings our traction battery SOC down and my subsequent morning warm-up includes replacing this charge.

Bob Wilson

 

Re: My Milegae experience Re: Consumer Reports Rating of 2010 Prius

OIC!! i guess i am confused about how the city test is done, because the PDF provides a COMPLETELY different explanation.

it implies that there is no length mentioned. what it does say is that the course contains

*18 stops
* 4 minutes of stop time
*total test time of around 16 mins (not sure of that one) broken up into 6 segments between 2 drivers each segment 2 minutes and 40 seconds.

so to make 4 miles in 2 minutes and 40 seconds, we would have to be doing around 90 mph.

ok, easy to see how they got 32 mpg now.

but all kidding aside... a repost of the PDF supplied by CR describing the testing process follows

These tests are stop-and-go city-driving simulations
on our test track, which has a total of 18 stops and 4 minutes of
total idle time. Top speed is 40 mph. Two different testers each
drive three runs for a total of six 2-minute, 40-second trials on
every test vehicle. Total test time is approximately 16 minutes.

 

Re: My Milegae experience Re: Consumer Reports Rating of 2010 Prius

I think the CR results are pretty reflective of my personal driving experience. I have a 4 or 5-mile commute each way with many hills and stops at lights and stop signs (I think there are 17 lights on one route that I go, and I had a red light at 10 of them on a recent trip). I've been tracking each trip recently, resetting the trip meter each time. My average mpg is 39-51 mpg one way, depending on the route I take, number of stops, weather, traffic, etc. My average speed is around 15mph (and it does take me about 20 minutes to go the 5 miles). For the first 3 miles or so, I hardly ever exceed mid 30's mpg.

 

I would love to see their critique, given that my experience is that the Toyota Nav system in the Gen III Prius is excellent. It has saved my rear more times than I care to count.