What did I do wrong?

Yes probably......to all of your questions.

The C is optimized for CITY driving. That does not mean 75 MPH.
Yes it needs to "break in" some.
Yes your mileage will drop off DRASTICALLY above 60 or so.

Give it some time and check your mileage in the city or on a trip on 2-lanes at 60-65.
My long term average (~3000 miles) so far is about 51.....but that includes almost NO time on the freeway above 60. With a little care, I can get ~60 around town or on a leisurely country cruise around 50 MPH.

 

Cold temps are your enemy, speed is your enemy. Cruise Control should be fine if it is dead flat, it is your enemy on hills.

Bob Wilson did a MPH vs MPG curve for the lift back, for the c the low speeds should be better, (it is a city car) and the high speeds worse (it is a city car)


Notice that it was over 80 degrees out when he tested.

 

It is too bad you did not read any of the text I wrote. 50 MPG at 82 to 86 degrees will NOT yield 50 MPG at 35 to 45 degrees, even in a liftback. I have no trouble assigning 3/4 to temp and only 1/4 to aerodynamics.

You may wish to search for grill blocking, or even Engine Block Heaters if desperate. I live in MS, (it was 81 yesterday) so I only grill block about 2 months, in MN grill blocking may be a 6 month strategy with EBH for 3 months each winter.

Fuel Economy Top 10 Tips in order of % effectiveness? | PriusChat

Engine Block Heater for 2012-2014 Toyota Prius c - PriusChat Shop

The traditional EPA test never exceeds 58 MPH, a 2008 enhancement, which the automakers could ignore until 2012, adds a 80 MPH burst.
The Truth About EPA City / Highway MPG Estimates - Feature - Car and Driver

Here is a Gen 1 owners month by month MPG in MN

http://john1701a.com/prius/documents/Prius-2001_MPG_Graphs_Lifetime.pdf

 

wind and elevation come into play, and tyre pressure as well.

 

The tires need some break-in, they will do better with some distance. Same with the driver. But I don't believe the car itself needs much break-in to produce good mpg.

Try this: Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new

 

The Prius is not a magical creature that just gets 50mpg right off the bat. It takes a little bit of a learning curve to get higher mpg with it, and as you drive your car more you'll learn how to optimize the mileage, if you care to. Yes, it takes driving it a little more laid back than you would a car meant for speed. My coworker traded in his Mustang for a Prius a few months ago, and gets consistently 46 mpg, but drives it almost like he used to drive his Mustang leaving it in PWR mode all the time. He doesn't care because 46 mpg >>> 16 mpg which is what he was getting with his Mustang.

You might want to check your tire pressure, maybe it's a bit low. The temperature makes a huge difference too, especially in the C, as it's battery is smaller it's not as efficient as it will be in the summer. Once you get up to 60s and 70s you'll notice a big difference. Do you have the heater on? The heater is drain on mpg. As stated in previous posts highway speeds aren't as efficient for the C as well (the C does stand for City after all). Try driving 65mph and see if you notice a difference as well.

Another thing about the Prius I did not know about when I got my first one is that the engine needs to warm up before it can switch to EV. This warm up is almost like a penalty for shorter trips, especially in cold weather, as gas is wasted heating up the engine at the beginning of your ride.

Try not to get too frustrated with it, and good luck getting your mpg up in the future! Alternatively, accept that you're getting much better mpg than your previous ride (I assume) and just drive it as you would any other car.

 

Well you only have 1000 miles on the vehicle as a whole.

One thing I have said in other threads to other new Prius owners, is don't worry or evaluate based on single trips, or even singular tanks. You've got to look at your average...maybe on a monthly basis, and over a longer period of time.

So far you have one tank at 48 mpg...pretty good. And one tank at 41? And I'm assuming those are your first two tanks?

Almost look at it from a medical/illness standpoint. If your Prius really is "sick" and has a problem? It won't get better, and the symptoms (poor gas mileage) will become undeniable. Then you will know...

At this point, with only two tanks, and 1000 miles, you just can't say. I'd expect you are fine and everything is "normal" but I also think you should expect better than 41 mpg gallon on average.

So just keep driving. And pay attention. See what your average is after your 4th tank and at 2000, 2500 miles.

If your overall average is still hovering in the very low 40's..then I think you can start to worry. I wouldn't at this point.

 

????

Wimpy? Only by the standards of the 1990s and early 2000s Horsepower Wars. As another poster repeatedly stated, a Prius as all the power an adult needs, but not all the power a boy could want.

Did you ever spend any time driving cars built in the decade or two after the 1970's energy shortages? My Prius would blow the doors off my '84 2.3L Mustang, which still had all the power I needed.

 

I'm sorry you are sad......but did you notice the sticker on the window that showed the mileage in the city to be HIGHER than it was on the highway ??
The C was not intended to get a lot of highway use and certainly not at high speeds.
If that's what most of your driving IS, then you probably got the wrong car.

 

That is really just an artifact of the EPA MPG scale with different empirical fudge factors for city and highway. Don't read too much into it.

While the highway may not be the ideal niche of the 'c', and it won't get quite the MPG of the liftback at highway speed, it would be harsh and misleading to say that it is not intended for highway use.

 

The design was optimized for low speed driving, as evidenced by the FACT that most all owners really DO get better mileage in city driving than they do on the freeway.

And as long as we are nit-picking semantics:
I did NOT say "it is not intended for highway use"........now did I ??

 

Just like others said just a couple more:

1. From 20 MPG down to 16 MPG you see only 4 MPG lost (20%). From 50 MPG to 40 MPG you see a big 10 MPG lost but still 20%.

2. Full loaded passengers and luggage is different than 2 people: how many people in your trip?

 

40mpg is low.

Check tire pressures
Verify handbrake is off

Perhaps an unlucky day with the wind?

If you averaged 75 mph though, a lot of your driving was over 80, and in that case the result would be in range of expected.

Bob Wilson's chart is a gem. Look what happens at 75 MPH and a 10 MPH headwind.

 

this is the result of an ambiguous epa testing system. i assume you are a young person, who up until now, was ignorant of this fact. learning the hard way is always difficult, i hope you can get past it. unfortunately, every now and then, someone will post here with an "i never expected this with a prius" complaint, and go on to trade it in, taking a bigger hit than the lost mpg's might cost.

 

That, and the EPA MPG inversion between highway and city, are no different than other versions of Prii. Many drivers see this result, but not all do.

I felt that was a reasonable paraphrase of your full sentence: "The C was not intended to get a lot of highway use and certainly not at high speeds."

Yes, the highway is not its ideal niche. But the 'not intended' phrase is often common vernacular for 'should not be used for', even if formal English doesn't produce the same meaning. This is where I disagree. If the 'c' is a better fit to a car buyer's budget, parking space, style preference and cargo load than is a regular Liftback, there should be nothing wrong with putting into 100% Highway service.

 

I don't think your "paraphrase" was reasonable at all.

And if one decides to put it into mostly highway service AND AT HIGH SPEEDS, they should not be complaining about the poor gas mileage.

THAT is the only thing "wrong" with that decision. They probably could get similar mileage out of something else with a tiny gas only engine and pay less for it up front.

 

The Prius 'C' will get very respectable (as in better than any other non hybrid) highway MPG at 70 MPH. So while truly unreal MPG is a city phenomenon, we should avoid inadvertently adding to the idea that the Prius is not a good highway car. It is in fact a very impressive highway car.

I'm not trying to pick on anybody, I just want to encourage useful feedback for the OP.