2010 Prius III - 18 mpg?!?!

Yes, sometimes right after I fill up and reset my counters I've seen 90mpg but that is only while I accelerate very slowly then I see it drop to 20 or less and work it's way back up.

 

It's not so much that the mileage is too low, but that the trip was too short to get the car to its more optimum operating mode - see the thread http://priuschat.com/forums/gen-iii-2010-prius-fuel-economy/77225-first-few-minutes-mpg.html for a more thorough discussion/description of warmup time and the resulting fuel economy.

 

I'm confused. Do you own a 2010 Prius now? Or have you never driven a Prius before? If you do not own one, I would say the above answer is true to a point but it is also a matter of how you drove it.

When I first got mine, I was getting 26 MPG or so and after 2 months I am now up in the 50-60's depending on the outside temp.

I had to learn how to drive the car and I am still learning that. This site is an excellent resource of what you will need to know to get the most out of the Prius.

 

i would say that it is due to the short trip. i hate filling up at work because it's entirely up hill on the way home, so the avg mpg says 26mpg.
however if i fill up at home and head to work, i'll be getting 70mpg on that same 10 mile trip. by the end of the tank either way i am averaging out to 50-51mpg.

 

Yes, you have to learn how to drive a Prius, particularly when it' i
s your first hybrid car.
I did it since 09 November.

 

No. Just a few miles is enough.

Next time, take a look at the: AVE MPH

If it's really low, odds are a salesperson was showing off the vehicle in the parking lot. Stationary with the engine running (for heat) will drag MPG down. And sadly, that often do that. Fortunately, that new gauge clues us in to what may have happened.
.

 

Two things to bear in mind about mpg calculations:

When gliding in "warp stealth" or regen (no energy going to the wheels, engine not running), you get "infinity" miles per gallon (whatever distance you go, divided by zero gallons).

When not moving but the engine is running (warm-up), you get negative infinity miles per gallon (zero distance, divided by whatever gallons you use).

And if you really want to melt your brain, take your Prius out on a really cold day - the gas engine will run to warm up, but won't provide any power to the wheels unless you really stomp on the pedal. Assuming you don't, all of the propulsion will be from the battery until the engine is warmed up enough - so your MPG is calculated based on the distance provided by the electric motor, divided by the gas consumed by the engine (which isn't propelling the vehicle at all)... The engine will use the same amount of gas to warm up whether you're moving or not, but the further you go on the electric motor during that time, the better your mpg.

 

Please be aware the 6 miles test drive starting a cold engine is a worst case.
Any driver can't record a good mpg number on that situation no matter how he drives.
Any car can't record a good mpg number on that situation, too.

It is more important to know how Prius is doing than to know how to drive it.

Next time when you do test drive again, ask sales person to let Prius warming up or drive more than 20 miles, then reset the previous mpg number.
Now, it's your turn to do the test drive starting a warm engine.

Ken@Japan

 

Yesterday the weather was 72 deg F in Cleveland. I drove 75.2 miles at an average of 63.6 MPG.

I do not drive any special way. Key things are keep the tires over inflated (45, 43 PSI) and do not speed.

 

I'm going to have to disagree with the any driver/any car part here... Once you get familiar with the car, and your typical driving routes, 6 miles should be plenty distance to bring the trip mileage up. HOWEVER, if that 6 miles is filled with 10 stops, crossing traffic, typical city situations, than I would expect the mileage to be low. Out on the stix, my typical morning (provided it's 30 and above) driving my kids to preschool yields in the 50-60 MPG range over 6 miles. The trip back can be in the 70s, provided I can pulse and glide. Otherwise, it's in the 60s.

I forgot to mention the roads... out of my development is one stop, with a second stop about 1.5 miles out. A third stop at mile 5. Fourth at 5.5. Sixth at 5.75, and then parked.

Return is much the same, parked to a light, hang a left and a right. Left at 1 miles out, stop at about 3.5. Next stop at 1 mile, then a left and parked at .5.

Roads are posted at 25-55 MPH (and 55 seems to be because I'm in NC, that'd never happen in PA considering the sight lines), and have very little traffic. Most days I don't have anyone behind me, and then I can pulse and glide all I want. With traffic, I just hope for the best using SHM when the engine warms up enough. At best, my wife will get about 48 MPG for that same trip, worse when she's running the heat.

 

Think about how much energy you consume riding a bicycle up and down a very large hill. Up hill, you consume a lot of energy, and down hill, you consume nearly none.

You can't count only the "up hill." Even a Prius gets very bad mileage in certain conditions, such as chugging uphill, or when it first starts up cold, etc. I've had mine two days now. I have an 85 mile round-trip commute each day. This morning, freeway traffic was stop and go, which is usually the worst for mileage on my other cars. Prius delivered remarkably good mileage in this traffic. I drove carefully -- I didn't mash the accelerator and then mash the brakes, I tried to coast, but mileage for the morning's trip was over 50 MPG.

 

When I was looking at the Prius I bought last month, one day I went to test drive it and the average MPG was 20. I couldn't believe it, so during the test drive I reset the average, and ended up getting an average of about 45 mpg. Turns out that the dealership had been moving the cars around the lot while they were plowing it, and had left the Prius idling for long periods of time. So far since I bought the car I'm averaging 47 mpg, with the first 5 minutes averaging 25 and the last 5 minutes averaging about 65-70.

-Ken

 

My experience was the opposite. Even on a test drive, I got excellent mileage in the Gen II Prius. The good news for me was that it when up even more after I bought the car and did longer commutes with careful driving. I routinely get between 52 and 59 MPG on the gauge, although the actual mileage is 5-8% lower. Either way, this is better than advertised.

 

No you don't. I drive more aggressive in the Prius than other cars I own, I still get 42mpg. That is still better than most cars out there.