Wow, you have to be kidding me!

I'm not claiming this is at the root of your problem, but I'm just pointing out that reversing the route can make a significant difference in mpg because of different traffic patterns and elevation change. I have noticed this even in the relatively flat state of Michigan. There is a 10 mpg difference between going into town and coming home - even if the car is already warmed up.
Hope they find (and admit to) the problem.

 

It never ceases to me how little information new owners provide. That leaves us with almost nothing to work with.

Speed and distance make a huge difference. What about the tires? Being a used purchase, what's on the car now? What about inflation? Did you check oil type & level?

What measurements have you tried? Something simple, like a steady cruise at 55 on a flat road for a few miles, can quite telling.

 

^^^
OP did answer the questionnaire at 2010 Prius 38 mph on trip 42 back... | PriusChat, but I had to dig to find it. I haven't been monitoring that thread.

As a data point, The most fuel-efficient cars is what CR got. Last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf describes their test vs. the old (pre-model year 08 EPA test).

 

my 2010 never goes under 60 mpg in the summer. Present tank will come in at 67 indicated, 65 real. Mixed driving, top mph is 60, never use AC, energy saver tires at 40 psi, always drive in ECO mode and try, if traffic permits, to keep the eco light on. Use stealth and warp stealth depending on road slope. no short trips - combine when I can. 40Kmi, 57 lmpg . Try checking brake dragging, wheel alignment, and watch Wayne's video on getting good mileage.

 

My company uses Priuses (mostly 2010 G3's, but some G2's) as fleet vehicles. I can tell you from personal experience that the real world mileages can vary wildly from 40 to 60MPG. Most of these delta's are caused by what's going on between the seat and the steering wheel, but there are also other factors that can affect mileages. Weather, tires, routing are some big ones. Mostly? It's either the driver or the route.
My personal G3 can repeatedly achieve 59MPG. That's hand calculated, tank average, all the way full to almost all the way empty, and when I'm hypermiling. However (comma!!) I've also had tank averages in the very low 40's during cold weather, when I'm on the interstate, when I'm not interested in pinching my company's fuel pennies, etc.
You have to almost ignore the MDF readings. I've never seen a G3 where those reading were within 3-4 percent of 'the truth'. The MDF data is good for day to day monitoring, but if you want the truth then you need to noodle the numbers for yourself.
It gets worse if you buy a used Prius. As stated above, things like tires, oil, the condition of your underbody panels, your 12-v battery, all can play a part in a Gx not getting it's rated mileage. If you have a "previously babied" Prius and you're sure that your driving style should be netting you more than you're getting, then you need to look at some of these things.

According to Fuelly.com, a G3 should be getting somewhere in the high 40's for miles per gallon, but YOU can make that number go about 10-mpg either way by how you drive and maintain the car.

Good Luck!

 

We have a 2012 Prius 3 and the advertised mileage is just not happening. The computer in the car tells us that we are averaging 48.1 mpg, but we have been checking the mileage the old way since the car was new, and we are really getting 43 mpg. This car is the worst purchase of my life and I am 67 years old. Had I wanted 43 mpg, I could have spent 10,000$ less and bought a Ford Focus or Chevy Cruz that get around 40 and I would have had $10,000 left over to buy the gas for the extra mileage. The worst part is neither Toyota Corporate or the dealer really give a damn.

 

^^^
As 2 more data points, the 2 Gen 3 Priuses at Advanced Vehicle Testing Activity - Hybrid Electric Vehicles are getting a cumulative 45.6 mpg and 43.0 mpg, respectively.

 

Please read Car and Driver: The Truth About EPA City / Highway MPG Estimates | PriusChat to learn about the EPA tests. EPA values are not to be interpreted as figures that you will get. See Your Mileage Will Still Vary.

The '12 Chevy Cruze w/automatics are EPA rated at 27 mpg combined vs. 50 mpg combined for the Prius c and liftback. See Compare Side-by-Side.

The most fuel-efficient cars is how Priuses did in CR tests. In comparison, this is how Cruzes did on CR's tests.
'11 Cruze LS 1.8L 6AT: 26 mpg overall, 17 city/36 highway
'11 Cruze 1LT 1.4L turbo 6AT: 26 mpg overall, 17 city/36 highway
'12 Cruze Eco 1.4L turbo 6 AT: 27 mpg overall, 17 city/40 highway

The Cruze also has HORRIBLE reliability in Consumer Reports. Versions w/both engines made up the two most unreliable vehicles in the small car segment. They were far worse than average in reliability.

If you have mileage complaints, please start a new thread and answer the questions at Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new | PriusChat

 

How do you know you weren't having a headwind going there and a tailwind in reverse? Have you confirmed that there's no elevation change between the two points via Google Earth can give you an elevation profile of a route between 2 points! | PriusChat

For instance, I can always see I'm getting better mileage going this one direction down an expressway from my house and worse mileage the opposite direction. I guessed there was an elevation change (downhill in the direction where I get better mileage). Google Earth confirmed it.

 

That of course begs the question of how closely you monitored MPG in the past. Back when gas was dirt cheap, most people only did spot checks at best. So, they really didn't know what to expect from their driving & conditions in the first place. After all, without ever having a screen available, how convenient was it to check?

When it comes to Prius, it's especially important to keep the YMMV notice on the window-sticker seriously. Things like short trips have a profound influence on efficiency. Outside temperature does too.

On a side note, I do wonder about the "worst" qualifier... clearly remembering how incredibly unreliable cars were decades ago in comparison.

 

^^^
It seems most of the responses at priuschat.com/threads/2010-prius-38-mph-on-trip-42-back.111856/ have covered everything. Those 3 mile trips and other short trip, esp. "around town" and in your very hot weather (I'm guessing 100+ F) aren't doing any favors for your mileage.

It would be interesting to get your car warmed up, take your car onto the highway, reset one of the trip odometers (to reset the mpg value), set the cruise control at say 60 or 65 mph and drive for at least 5 minutes. Then, turn around and do the the same on the same highway, then the report the mileage you get. That will help cancel out effects of elevation change and winds. It's probably best to continue mpg help discussion for you car in that other thread.

Your tires are most likely not LRR and thus hurting mileage. The fact that they're new doesn't help either (Tire Tech Information - Tire Rolling Resistance Part 3: Changes to Expect When Switching from Worn-Out to New Tires).

 

whatever you're getting in the loaner, you should get with yours. don't settle for less, be proactive and pursue more answers. you can still enjoy the car in the meantime. why give up 10 mpg's?

 

^^^
Problem is per the OP's answering the questionnaire at 2010 Prius 38 mph on trip 42 back... | PriusChat, she has Accelera 651 195/65r15 tires. I've never heard of them. The loaner likely has one of the factory tire choices w/better rolling resistance characteristics.

 

I have experienced mpg's all over the chart while driving rental Prii since 2009. The worst cars were the ones with generic Mr Donut non-LRR tires. The best had OEM tires on them. I always ran 45 psi in all tires. In my own Four, I can average 30 something on under 15 mile trips. If I go further it goes back up to mid 40's. Further yet and I can get into the 50's with a bit of careful driving. I have LRR tires but they are the 17's so my mpg is lower than a regular Prius.

Mike

 

The direction of a route can change as much as 10 MPG on a Prius.

I can often get the Prius to achieve 74 mpg on a 16 mile commute route that has a drop in elevation of 200 feet in the summer time.

On the way back using that same 16 mile commute route where I have to climb 200 feet in the same weather conditions the best I can achieve on a Prius is 64 mpg...

and I am hypermiling so I'm pulling every trick out of the book that I can muster to maximize the Prius' MPG..

You might think that's great - it still averages out to be about 69 mpg -- but when I start doing those 5 minute hops to the local grocery store - the Prius only gets about 20 to 30 mpg on the average. And if I do enough of these short trips on the Prius - its overall MPG will drop like a rock. This dramatic fuel efficiency drop for short trips is because the Prius ' primary design function is not fuel efficiency but near zero emissions. High MPGs is only a side effect of having near zero emissions when you drive it a certain way.

 

EPA mpg ratings are based on standardize tests which probably doesn't reflect your kind of driving - so you are not achieving the same levels of fuel efficiency as the EPA MPG rating. I also drive differently from the EPA standardized tests but I get about +60 mpg (20% better than the EPA MPG rating ) via hypermiling techniques. However, if it is any comfort to you (misery loves company, right?)- Consumer Reports rates the Prius MPG at about 44 mpg which is about what you are getting.

Almost all the MPG displays on today's cars are optimistic by several miles per gallon - the Prius is no different.

The new hybrid technology on the Prius(and other full hybrids) often requires that the driver relearn how to drive to get the best MPG - much of the Prius' fuel efficiency advantages is premised on that trips that are over 7 miles/30 minutes long. This phenomena is not normally covered in the general press (WHICH IS WHY PRIUSCHAT FORUMS ARE A VALUABLE RESOURCE)- Simply put -short trips hurt the Prius' MPG performance. Conventional gas vehicle like a Ford Focus or a Honda Civic can offer similar short trip fuel efficiency at a better price - if that is all you are going to do. However, the Ford Focus only gets 40mpg on long superhighway trips (which are over 7 miles/30 minutes long )-- for short trips under 3 miles/10 minute - a Ford Focus is going to get about 30 mpg for most drivers. yeah Ford is playing the same game as Toyota. Surprised? Don't be. If you find yourself at that stage of life where you need to simplify your life - you might want to switch back to a conventional gas vehicle.

With respect to getting better MPGs - money will get you only so far - the rest is dependent on the driver skill. Even after studying hypermiling for over two years -- I'm still have not mastered all the techniques. However, even with my limited skill set I can beat the EPA rating - even in the winter time.

 

Yep, as a hint for the other posters and a teaser to read the articles and info I pointed to: on the EPA tests, they don't drive on a real road, rather a dyno (rollers). They don't measure actual fuel usage, but rather derive it from tailpipe emissions. The highest average speed on any of the test cycles is only 48.4 mph. Only two of the cycles start from a cold engine and each of those are 31.2 minutes long.