Prius overall MPG shows no improvement in the 3rd generation according to Consumer Reports tests

I think the difference is "live in the city" versus "drive in the city".

If you live in the city, you may well make a lot of short trips, which will kill mileage. If you commute through the city, or spend some of your commute in a city, it's a different story. And theoretically, the hybrid tools (regen braking, EV) get used more in the city than in more constant, high-speed highway driving.

 

People use "fast" and "slow" loosely and it creates confusion. Do you mean high top speed, or rapid acceleration? (Or something else, as I will mention.) You can drive everywhere at 75 MPH and get EPA mileage. You can't takeoff from every stop doing 0-60 in 9 seconds and expect to get great mileage.

AN interesting, anecdotal data point: I was at a video shoot yesterday when my wife called and was feeling ill, so I rushed home. I was going 80 most of the way and didn't hesitate to hammer the gas as needed. (She was feeling badly enough that I stayed on speaker on the cellphone all the way so I could call 911 if she stopped responding, so I was in a HURRY.) Obviously, I already had 50+ MPG on the meter from the trip to the interview, but as I remember, I got home with little change in MPG.

Why? Well, the engine was obviously warmed up already, which helps. And even though I was generous with the gas pedal, I was driving in conditions that meant I wasn't jumping on the brakes shortly after hammering the gas. I really think that people who complain about "I have to go fast" really mean, "I accelerate hard in order to turn around and brake hard".

A key to good mileage is smoothness. Smoothness, plain and simple. Which is not the same as slowness! I've used the story before, but a good example is Jackie Stewart, a Formula One racer who had his own driving school. One of the exercises he made you do was he taped a shallow salad bowl to the hood in front of you and put a ball in it and had you drive around the track without the ball flying out of the bowl. The idea was that you could drive fast and smooth, and smooth is a key.

A lot of people who are into "I need to be fast" get the feeling that they are fast because they throw the car around. Not you, necessarily, but you used the word "fast" in the sense that they do, and I'm just running with that.

 

Thanks for all the links to other information. Regardless of how "city driving" is defined by EPA or CR, I have found my results on my Gen II, as well as the Gen III (only 600 miles on it though) to be fairly close to the CR results. I know that many of you are getting much better mileage for both city and highway, but there are others like me who aren't getting up in the 50s for city driving -- and I don't think it's anything wrong with our technique necessarily.

In my particular case, I am actually in a suburban area, not a downtown city area. But anybody who's familiar with the DC metropolitan area knows that the traffic is probably comparable, if not quite a bit worse, than other major cities' downtown areas. My daily drives involve 5 miles each way to the Metro station. The first mile is all uphill and then the rest is up and down. I don't know exactly how many traffic lights I pass, but I probably have to come to a complete stop at at least six. The last part of the drive involves going up the ramps in a multistorey garage. I definitely notice an advantage in the Gen III for this last part because I can usually go into EV mode (although sometimes it won't let me because the battery doesn't have enough charge, which I don't understand) and I see the mpg actually climb a few points. With the Gen II, it would drop when climbing the ramps. This little 5-mile trip generally takes me at least 20 minutes in the morning! On my return trip, I usually have less traffic and fewer lights because it's after rush hour by the time I get home, but there's more uphill driving. With the Gen III, it's around 47-48 mpg on the MID for these commutes. However, my calculated mileage at my last fill-up was less than 45 mpg (trip odometer showed 47).

The other day I drove 30 miiles to Springfield on the highway and it showed 53mpg on the trip odometer. On the way back, I had to go through the city, and then drove home on a road with many lights and which was uphill all the way. No matter how hard I tried to stay in the ECO zone, it was almost impossible with the uphill climb without slowing down completely and my mpg dropped all the way down to 45 from 53.

So, as far as I'm concerned, the CR results are quite realistic. On my Gen II, my 3-year average over 30,000 miles was about 43.5 mpg (although I was getting much higher averages at the beginning when I was making longer trips).

 

No one, including Consumer Reports can be an expert on everything. My Gen III easily gets 5 MPGF better than my Gen II. Now it will be interresting to see if the drop in mileage for winter is as pronounced as it is with the Gen II. Here in Portland, the terain is very hilly, and I go over a couple hills to get to work. I have a scan guage that I reset once the car is warmed up at the top of the first hill (YES, I know this is major cheating) and I always get over 50 mpg on an all highway commute with Tank Average of 47 including the warm ups. When I get off the highway and go 35 on the side road with no stops, I get 70 + MPG, and just putting around town with stop and go, I get 50 easily.

 

I had exactly the same experience this weekend. The weather is brutal and SOC just sinks with the high AC use. Of course, it didn't help that my wife took the car on Friday and somehow managed to drop the measured mpg from 41.5 to 38.1! She also wants a lower temp than I use when alone. I haven't been able to get back above 40 yet, even with an interstate trip to Sugar Land in the mix. Considering the measured is running 5% lower than the computer, the 2010 with 17" wheels is not doing that much better than my HyCam.

 

Sitting in the car with the AC running, ggood ? That is my wife's story, and she is sticking to it.

 

That's the beauty of HSD. All ICE's get better mileage driving steady highway. But Hybrid HSD and The Prius itself was designed originally for use in large congested cities. So the heart of the system is really designed to produce lower emmisions and use less gas in congested city driving.

I believe some of the original thinking behind HSD and Toyota's Hybrid design was the idea to produce a vehicle large cities such as Tokyo and New York could employ as utility vehicles and reduce smog.

It should be no suprise the City driving is rated higher, cities are for what HSD was designed.

Thus you get the engine shut off at stops, the switching between gas and electric and the ultra low emmisions. Plus of course great city gas mileage.

 

The only reason I can think of why CR measured a lower city mileage is the fact that the Gen III is heavier than the Gen II by about 70 kg. If their test contains more stop-and-go traffic instead of slow-fast traffic, then it could explain the difference.

Having said that, I have another experience, and think the Gen III has better fuel economy in every type of traffic. Although I do not do much inner city stop-and-go. I prefer the bike for that. And I do not use much of the A/C.

 

This is one of the reasons I never pay attention to what Consumer Reports has to say. Their reports are only as good as the person doing them ... and what their bias might be.

I had a 2008 and now have a 2010. What I just read from the item from CR just doesn't reflect real world experience over thousands of miles. The only way I have gotten mileage that bad on my 2010 was by cruising at 80+ into a headwind. On Interstate 10 in west Texas, you can cruise at 80+ for a couple of hundred miles.

To say that my 2008 and 2010 are basically the same car is a CROCK. Actual use says they are much different ... and the 2010 is a much better road car.

Anyone with a subscription to CR needs to cancel.

 

Exactly! Of course, Insight and Honda fan boys can't be convinced of that.

Most fuel-efficient cars answers your question except that the 2010 Prius figures aren't there yet.

 

The reality of the Prius (and presumably any hybrid to varying degrees) is that most drivers do learn some good habits in regard to acceleration, braking and overall driving to maximize fuel economy. For that reason alone, any standardized test is probably going to be conservative with regard to fuel economy results, at least compared to what many owners experience in the real world.

Someday, CR will have a 150 mile loop where they drive like a hybrid driver.

 

Those numbers are about right if you are not making an effort to drive smoothly. If I drove with a heavier foot (not lead foot), I get about 35-36mpg in-town with a '07 Prius rental. This is with the A/C on and on flat land. If I did a highway run from Santa Cruz to San Jose, CA, I get about 41-42. All of these figures are according to the onboard computer.

 

There is another mileage metric, user reports:

Generally speaking, we like to see at least 35 samples in a mileage database but double-hump curve is interesting. It is as if the early EPA records are showing two, distinct driving populations:

1. The first group is driving the same profile and performance as the NHW20
2. The second group is driving a profile that optimizes ZVW30 performance

The mileage poll in Prius Chat shows a remarkably consistent Gaussian distribution. A snapshot in time, it still is interesting and our votes are smack dab in the middle of the EPA double-humped numbers.

Bob Wilson

 

I'm looking at the September issue and on pp. 52, they've divided the cars into two group at $24,000. If they'd gotten the $22,750 version it would fit in the group along with the Jetta TDI and top rated Nissan Altima. But the $26,550 is in the next group that includes the Nissan Altima 3.5, Honda Accord and upscale Camry. It will be interesting to see what happens in the review and if they are ever able to getting an under $24,000 Prius.

Bob Wilson

 

Well, I don't know how you get 44mpg with this car. Goes against what my friends get and from what many here say. I suppose the test drivers have heavy feet.

 

Maybe the numbers are in the Forum somewhere in here, but I'd like to see the average mileage for a large number of folks driving the new version and the previous version of the Prius. Calculated by mileage, I drive 70% freeway (route 80 - 65mph) and 30% in stop and go in Davis and Sacramento. My previous car was a corolla with a 1.8L engine and I got 38.5 driving the same route. BUT, I got 38.5 only by coasting to a stop whenever I could, by driving no faster than 65 on the freeway, and by turning off the engine whenever I was stopped at a light for more than 10 seconds. You'd need a smaller engine than 1.8 to get more than 40 mpg. Today's small cars just don't get higher mileage.... perhaps because of higher compression? I just got my Prius and without even thinking about driving I got over 50 on the first tank I filled (not the dealer filled tank). I don't drive real fast, but I don't drive that slow either and that leads me to believe that you get low 40s with a heavy foot. Too much acceleration perhaps?

 

Looking over the calibration data for the mileage display, I noticed that the display is more accurate at low numbers than high:


To show the degree of error, they might need to drive the car in a more fuel efficient region and there in lies the conundrum. To show the mileage indicator error, they would need to use a speed range that might contradict their 'official' mileage report. <grins>

Bob Wilson