Prius c only getting 43mpg avg

Go back to post #19 on the very first page of this thread and watch the video as many times as it takes to' get it '. Watching the 5 minute screen is not nearly as productive.

 

Assuming a properly warmed up car and proper tire pressure, you should be able to achieve 48 mpg at 65 mph (Best & worst fuel economy | Consumer Reports). They run their highway test at 65 mph in both directions.

You may be encountering headwinds and/or elevation change (Google Earth can give you an elevation profile of a route between 2 points! | PriusChat). It may be cold in your area, which doesn't help either.

 

I just bought my Prius C this past Saturday, and was expecting to get in the upper 40's MPG on the highway given the EPA rating. Imagine my surprise when driving the next day on a 60 mile highway trip and averaging over 50 MPG. I've averaged over 50 MPG on my highway drive (30 mi each way) back/forth to/from work each day this week as well.

Not sure what might be different than your driving conditions, but in just the three days I've had the car (hardly a good sampling I know), here's what I've noticed:

* MPG is pretty poor when the car first starts up. After 5-10 minutes it seems to "warm up" and MPG improves noticeably. Oddly, this "warm up" period appears to be necessary even if the battery has a good charge from the get-go.

* I drive "like a train" to maximize economy... slow, gradual starts and equally slow, gradual braking. I also use the "B" gear often on the highway to help slow down in place of braking when I have the distance.

* Ignoring the start-up warming period, the thing that seems to eat into MPG most severely is heavy acceleration and needless braking (change lanes if you can to avoid braking and having to regain highway speeds). Keep thinking "drive like a train"... take a long time to get there but once you're at a good speed, try to stay there.

* Note: I stay in ECO setting and also I'm not shy about going fast... I'm typically cruising at 65 to 70 MPH on the highway and still able to top over 50 MPG by the time my 30 mile drive to work is complete. HOWEVER, I only reach that 50 MPG near the end of my drive... at the 1/2 way mark home I'm usually only in the mid 40's not having had time to overcome the initial warm-up period and braking/acceleration to get out of the city and onto the interstate. If I were to drive a few miles further, I think my MPG average would edge up a little higher... as it did one day when I kept driving to run an errand after work and managed to get up to 57 MPG with the extra 10 miles... and this was virtually all highway driving.

let us know if reading any of that sheds any light on your situation. thanks!

 

I have no c, but a Gen 2. All cars get terrible mileage while still warming up and yup it's noticeable via the MFD (at least we call it that on Gen 2). As for the warm up period being necessary, I believe it serves at least two purposes: getting the engine up to operating temp, getting the catalyst up to operating temp (to keep emissions down).

I wouldn't use B mode, BTW.

 

Agree. I just ride the brakes.

 

Once you get going on the highway, how long (how many miles) do you continue to drive before the trip is over?

I've noticed that just 5 miles into the highway drive my MPG is pretty low having "blown" my average having to speed up to get to highway speeds. At about 15 miles on the highway I've managed to "make up" for some of that and usually see an average (since the start of the trip) in the mid 40's. But it's not until near the end of the 30 miles that I see the average (since the start of the trip) push to the upper 40's and over 50 mpg. Today it topped the 50 mark within 2 miles of my house. If my commute were only 1/2 as far, I would have pulled in the driveway when the average MPG reading would have shown the mid 40's.

I know that this car is "supposed to be better at city driving" making it seem like the stop/go of the city traffic would get it the best numbers. But ironically I've found that once it gets cruising steady on the highway... gradually the average climbs up slowly.

In my case I high the highway after about 5 minutes from starting up the vehicle, so here's the pattern coming home from work:

* First five minutes spent in stop/go traffic. MPG looks pretty bad because of initial warm-up. It looks a little better if I try to do all my slow city creeping in full-electric but still is in the 30's or 40's average.

* Pull out onto the highway and watch my average sink fast with all the gas used to get up to highway speed and merge with traffic. Average will be in the 30's or low 40s for the next 10 minutes.

* 20-30 minutes into the highway drive is when the average starts to magically creep up to the upper 40's and slowly tops 50 mpg average within 5 minutes from home (given my 30 mile, 30 minute commute).

 

It does better in terms of EPA city rating. See Car and Driver: The Truth About EPA City / Highway MPG Estimates | PriusChat to learn more about the test.

It doesn't in CR's city test at The most fuel-efficient cars | Consumer Reports, but they have a very short city test (see last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf for a description of their test vs. the old EPA test).

 

Some days I just use it all the time - if I'm driving on major arterial roads and the traffic is flowing, then I can't pull out the tricks and the cruise isn't going to do things any differently to how I would.

Drove from work to my mother's place today - Used cruise for much of the drive at 50, 60, 70 and 80 km/h. Stats were:

Avg. Speed 52 km/h (32.3 mph)
Driving Time 0h25m
EV 13%, 2.9km (1.8 miles)
Outside Temp 19 C (66 F)
From Start 3.7 l/100km (63.6 mpg)

Forgot to capture the same screen on the way home, only got the Trip Summary screen when I stopped for fuel, but with a nice warmed up car and being able to use cruise control at 60 or 70 most of the way it gets better, with a calculated average speed of 45 km/h (28 mph):

Distance 15.0 km (9.3 miles)
Time oh20m
Consumption 3.2 l/100km (73.5 mpg)

I wish my commute to/from work wasn't so short and holding my overall averages down. I love when I can meet or beat the Australian rated consumption figure of 3.7 l/100km urban.

 

My average has been going up of late. Upward trend since 5000 mile service.

With that said - 60mph when warmed up gets me my best MPG, about 58+, on my display after about 10 miles on the highway. Average speed here tends to be low because of the traffic situation - even on the freeway.

PC2 with stock 15" tires.

My Fuelly average is about 2.5 to 3 MPG under the car display.

YMMV (literally)