Prius Actual Gas Mileage VS Advertised

what speed do you set it at and what is advertised highway mpg's?

 

Assuming that you're driving a Prius v, I'd say that you are doing quite well given that the advertised EPA is 40 highway, 44 city.

 

Take a look at Fuelly to see the real world numbers
2012 Toyota Prius MPG Reports | Fuelly

Fuelly average for a std Prius is 48 mpg pretty close to your 45-47 mpg.

 

As already mentioned, if you have the 'v' wagon (you posted in the 'v' forums), you are doing just fine.

If you have the regular liftback version, then read and answer this post: Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new

 

You are getting the advertised mileage.
You just didn't read the fine print.
They always say.... Your Mileage May Vary.

Ignore the MDF.
Ignore the DTE (distance till empty.)

The reason that you're not getting more than 450 miles out of a tank is that the fuel gauges in Priuses don't measure the bottom 20 percent of the tank. How much gas are you putting into the car?
If you have a G3 (2010-) then IIRC you have an 11.8 or 11.9 gallon tank.
Your tank range should be at least 500 miles---even the way you drive and whether or not you have the station wagon.
EPA "highway" driving is waaaaaaaaaaaaaaaaay different than SoCal highway driving.

YMMV!

 

Welcome.

76 mph is well above the "advertised" value. The EPA estimates don't take speeds that fast into account. So, you're results are actually pretty good. Watch what happens on a slower stretch of highway, closer to what the measurement tests use.

Unfortunately, it's far too easy to focus on the big sticker numbers and not notice those in the smaller print. People don't realize it's a range where factors like fuel, speed, and temperature all have a major influence. Things like tire-pressure and oil-level do too.

Search the forum and ask questions. There's a wealth of info available for new owners here.

 

yep, it's the speed. they don't test them at 76mph. there is a graph here somewhere that shows mpg v mph.someone will post it. you're in good shape, no worries.

 

So your car is rated 51/48 and you are getting an average 46 mpg doing 76 mph? Sounds to me like you are doing really good especially at those highway speeds.

 

When it shows 15-20 miles to empty, there are usually about 2 gallons left in the 1.9 gallon tank. If you are going to stretch your range you will be better off going by how many miles past 0 miles you go. Note that it won't read negative miles so you need to keep track of miles past 0 yourself.

 

Here it is: Updated MPG vs MPH chart

 

Pushing 76 mph is the cause of your reduced mileage. Cruise control may not be helping either at that speed, especially if the car is straining to maintain that speed going up even slight inclines. You would do much better if you slowed down to 65, and let your speed slip a bit going uphill and making it up on the downside. But 46 mpg doing 76 mph...c'mon, you're doing great.

 

+1, Johndoe if you can tolerate 65 mph try that for a max cruise setting for a few days and see what happens.

 

I'll wager that if you set the cruise to 68 mph for the part of the trip you usually go 76 mph, you will average 50 mpg. It will add about 5 minutes of driving each way, and extend your miles/tank about 40 miles.You will have to fuel up less often, save fuel cost, and pollute less.

I often care about safe maximum range for my tank because like you, I have a long one-way trip and I try to fill up at less expensive stations. After 400 miles or so when the tank MPG on the meter is pretty stable, you can use that number * 11 for maximum safe range. Or knock off 20 miles from the result in the beginning to help allay anxiety
I avoid saying '500 miles on a tank' because a strong headwind or bad roads in the winter may make that statement wrong.

As mentioned, the tank is 11.9 gallons. I fill up using the slow rate on the fuel nozzle so that the pump does not end early from pressure burps.

 

You'll also be negatively affected by winter weather and winter blend fuel. Most of us Cali guys lose 5+mpg when temps drop below 60F and winter blend fuel kicks in. Once temps go over 70F, mpg goes up noticeably and over 90F mpg shoots up nicely assuming you keep the AC off.

 

Please read Car and Driver: The Truth About EPA City / Highway MPG Estimates | PriusChat if you want to learn about the EPA tests.

You mentioned "I keep the cruise on 76 miles per hour..." That'll hurt mileage for sure. The HIGHEST average speed of ANY of the EPA test cycles is only 48.4 mph. The tests aren't run on a real road either, but rather on a dyno. And, they don't measure actual fuel use but rather derive it from tailpipe emissions.

You can see those numbers at Detailed Test Information under Detailed Comparison... Do look at the graphs too so you can see how much time they spend at above 70 mph (not much).

From The Most Fuel-Efficient Cars | Best Cars for Gas - Consumer Reports and Best Vehicles for City & Highway MPG | City and Highway Mileage - Consumer Reports, one can see the Prius liftback has the highest city, highway and overall FE for non-plugin vehicles.

From the last page of http://web.archive.org/web/20060129105844/http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf, you can see they run their highway test at 65 mph. The EPA tests described there are the old EPA tests.

 

DOE MPG curve is very different. I think Bob did pulse&glide in his chart.
Compare to this: MPG vs MPH, MPG vs ambient temp, and more from DOE testing | PriusChat