Abysmal city driving fuel economy

I figure it can't be too bad and I'll sacrifice 1 MPG to be happy with the wind blowing on my face.

 

My experience has been that if it is tolerable to open the window, then I get better MPG doing that than using AC.

You can lower the fan speed, which helps some on the battery drain, but that won't affect compressor speed. Instead, raise the desired temp.

But no matter how you have the HVAC set for cooling (as opposed to defrost), ICE does NOT have to run. The ICE running is incidental because the battery became low (two bars or less). HVAC will be quite happy to cool without ICE running if the battery charge is sufficient. Granted, if you are mass cooling, then the battery will drain in a minute or two, then ICE will start to maintain charge.

 

Prius has an electric variable speed scroll type compressor. google it. It is an industry first in many regards. The most energy efficient way to run the AC is to blow all the vents towards you and adjust the temperature up until the fan slows down to low speed. If that is not quite cool enough, then turn it down one degree. This will cool you but not the whole car. At long red lights, I sometimes turn it off and roll down the window or turn off the compressor intermittently and just run the fan. This is only when I'm alone and going for ultimate mileage.

 

I noticed you can shut the A/C off and just leave the vents on from outside (it is automatic for me, when A/C is off the vent auto open). Then slightly open your window, just a crack, and your will feel cold air come across the coils also. I do this at long lights (turn on fan on low).

I use the A/C all the time now and have only noticed a 1 mpg (if even that) drop from my usual MFD display value.

 

I actually notice a rise at first with
ac use due to the warmer temps. Once it starts to top 100 the mileage starts to drop as the
ac works harder and the battery starts to require cooling. If I park in the hot sun the battery gets really hot and the start up mileage is just terrible until it cools back down. The cargo cover and tint help.

 

As soon as my tint cures (1 month) I will start using my prius chat heat shades again. I got shades for all the windows. I am hoping with the tint, heat shades, and dynamat the inside of my car will not get past 80-90 deg, instead of 120.

 

I have had my Prius for 21 days. My trips are mostly short ones, 1-2 miles, and some 10 mile round trips. It has been a cold May here and I am getting 47 mpg.

 

Prius is supposed to get better city mileage. I believe most of us do. MPG drops substantially above 50 MPH.

 

I definitely get better mileage in town.

 

I have 2 routes that I can take to work one is flat and at 50-60 miles an hour and the other is flat and the speed is about 30 with at least 15 stop lights. If I take the low road and go fast I average about 4.7Liter per hundred Km. Slow route average is about 4.2 L. per hundred.
4.7 L. per hun=50 US mpg
4.2 L. per hun=56 US mpg
I opt for the 50 mpg route as it cuts the commute by 15 minutes.

 

Depends on what you mean by "city". Driving around downtown Chicago, where you stop every block and then some, 40-45MPG is pretty good, and it can be worse sometimes. I get GREAT mileage when it's slow-n-go on the highway, around 35MPH with occassional stops (this is frequent), but if it's stop and go for a long period, mileage plummets. Suburban conditions, 35-50MPH sustained speeds with few stops give incredable mileage.

So it depends.. I can get better city mileage than highway, depending on conditions. Those conditions are few and far between, unfortunately. What's really amazing is the difference Prius gets in the city compared to a conventional auto. Conventional cars have a terrible time with the stop and go conditions I described above, ESPECIALLY a 4cyl with the a/c running (performance also suffers). I used to get 17-22MPG in my Saturn 1.9L Coupe with all city conditions (25 EPA City) vs 42-45MPG in the Prius. The 2dr saturn copue is not a big car!!!

The difference in mileage the Prius gets in these conditions (even if not the Prius's best) is amazing! Plus, it still gets better mileage than the rest, even on the highway, even if that's not as drastic.

 

Interesting... So how many people (if any) are actually getting better MPG in-city than highway?[/quote]

In a rural city (pop. 40,000) w/no traffic signal coordination, poorer than freeway, unless I go with the 75 mph prevailing flow. On Los Angeles rush hour urban freeways mileage improves greatly with stop and go, where speed rarely exceeds 45 mph, unless I try to keep a small gap between myself and the car ahead in my lane, by accelerating quickly when traffic is in the "go" mode. Even then, MPG is comparable with speed limit freeway MPG.

BUT, I don't trust the MFD calculations. They vary, both from actual mileage calculated manually at fill-up (assuming that filling station nozzles all shut off at the same level), and in the differences between displayed averages and calculated averages. :?

 

<div class='quotetop'>QUOTE(Tadashi\";p=\"92566)</div>

Kudos for including the chart, and for your work maintaining that record!
Anecdotal contributions are entertaining, but actual data are invaluable, and enhance the site's contribution to the internet experience. 8)

 

At 3200 miles. I'm definitely getting better mileage on the highway than in the city. On a recent 1090-mile round trip to Wyoming, the car got 59 mpg. However, only a third of that driving was on 75-mph interstates, where for the most part my wife and I drove 65-70 mph; most of it was on two-lane roads at 55-60 mph, and a couple hundred miles were in the mountains at 35-45 mph, where the mpg really soared.

In town, the short trips and stops/starts generally keep me under 50 mpg, though it's improving with the warmer weather.

 

After 3 tanks of 50+ (4 tanks, if you believe the MFD), I was feeling a little disappointed that the MFD has shown 47+ to 48+ on the 100 miles so far on this tank. The miles put on have been on short trips, from 2 to 8 miles on the whole.

Then I got to thinking about the Grand Voyager I had before. When my commute was over 10 miles each way, I got 21 or 22 mpg. Then I got a job 1.1 miles from my home, but I still needed to drive because as a teacher I had a lot to haul. My mileage dropped to 16 or 17 mpg, but I filled the tank less than half as often. Even though I'd love to be in the high 50's or even reach 60, this kind of puts a different perspective on 47 to 48 mpg.

Still happy,
Beth