Our mileage is disappointing, wondering if it's normal

yes, up to 5 mpg negative

 

great tire though, many happy reports here

 

You might want to check the tires for their economy rating. Prius does best with low rolling resistance (LRR) tires. Most brands put an ECO or Green type label on the sidewall, even a leaf. Tirerack.com can give you the specs on your particular model. Poor tires will definitely give lower MPG results. And you said you noticed this even before moving to Nashville...

 

Michelin Defender XT are maybe a Costco iteration? Some have the "Green-X" label, and the latest version has been saying "Total Performance". I'm not sure that they've change much, are a good tire, decent rolling resistance.

Regarding the recent drop in mpg, try a fuel injector cleaner, the kind you pour into the tank at fuel-up. Look for a good rated one with PolyEtherAmine (PEA), which is supposedly quite effective at cleaning the injectors.

Your 12 volt battery may be undercharged, with the short trips. If practical with your parking situation, consider getting a smart charger, 3~4 amp range, one that can be left on indefinitely, if needed. Plug it in on days when the car will not be used, and leave it hooked up until next drive.

Exhaust Gas Recirculation circuit may be starting to clog. I kinda hate to mention it, but it's pretty much inevitable, with all 3rd gens. Not sure how much it might impact fuel economy though.

For short trips:

1. Consider getting the Toyota block heater installed. That'll raise the coolant temp around 20~30C. Temp plateaus around that level with about 2 hours plugged in. Plan for the time you forget to unplug, ensure the cord is very secure at the car, and the extension cord is also secure, and will pull out easily.

2. "Severe service" was mentioned up the page. Repeated short trips is one criteria constituting severe service. Consider doubling up the service interval, to 6 months or 5K miles, whichever comes first. FWIW, just across the 49th parallel, Toyota Canada calls that the regular oil change interval, for 3rd gen. (With 4th gen they're in line with the US.)

Tips:

1. Especially when partially warmed, experiment with turning the cabin temp down, and/or the AC off (if it's running). Or turning the vent system right off, rolling windows down instead. The car will shut down a partially warmed engine at red lights much more readily, if there's little or no cabin heat/vent demands.

2. Consolidate trips as much as possible. Avoid "impulse" trips, especially short ones, or consider walking if practical.

BTW: our situation is similar, if not worse, lol. We're now putting around 6000~7000 kms a year on the car, lol.

 

Check it's voltage with a digital meter, first thing in the morning, preferably with the hood left ajar the night before. Just opening the car doors to pop the hood (assuming you check at the jump point, in the under-the-hood fuse box), will drop the measured voltage somewhat.



If you get a reading 12.6 or higher, say up to 12.9, the battery should be in pretty good shape.

For a more complete assessment, most battery retailers will test the battery with an electronic load tester, for free. Dealerships will also do it, but might charge $50~75 for the service, and aren't that convenient.

You can DIY the test with something like Solar BA5. The connection with these testers has to be right at the battery, directly to the posts.

 

I drive on a weekly base l.a to vegas avg speed of 75 mph with one stop. My tires are worn and are never the best condition no LRR. I average 50 mpg.
I noticed when driving in vegas it goes to 56mpg. Driving in l.a i get 42 mpg.
Hope that helps

 

Run a couple tanks with injector cleaner through it.

Posted via the PriusChat mobile app.

 

Funny, I put a like on that without even checking what thread I was in, because it's never a bad idea, lol.

 

I drive 60 MPH where it is VERY flat. (it gains 90 feet in 156 miles) so my mileage is just a reflection of how warm the car is. (and which way the wind is blowing)

In Winter, the mileage may level out in 20 miles, in Summer under 10 miles. never under 3 miles. beyond that I get fabulous mileage.

 

What is the ethanol content of the gas that you regularly use ?

You can try an A/B test by comparing mileage based on gas with minimal or no ethanol content compared to the regular gas that you buy .

Do not put a higher octane gas in Prius as it will surely complain (Atkinson cycle issues with higher octane).

In 2014, toyota made changes to the prius engine for efficiency. Toyota introducing new series of gasoline engines with gain of at least 10% fuel efficiency; up to 38% maximum thermal efficiency - Green Car Congress
So in comparing notes with others, may be helpful to see if they have the same engine as your model year.

IMO (rather an uneducated suspicion), 2011 Prius engine was engineered for a time when our gas did not have increasing percentage of ethanol. A few years ago, there used to be lines stretching out the local Safeway for people to gas up because of favorable price. Today, not much of a line anymore at local Safeway even though their pricing is still favorable. Somebody knows something I don't.

 

They may have been developing new engines in 2014, I don't see this meaning the 2014 Prius model year engine was any different. Having said that, 2014 saw a revised piston, and 2015 revised piston rings, but those two changes were in effort to stem oil consumption issues.

 

My 2002 Town&Country is a flex fuel motor, as were other vehicles. I think Toyota knew about the ethanol in the fuel.
It's about the rubber and gasket seals they use, the ethanol will eat the older seals. And I guess some software info
for the computers.

 

My two cents when I rolled off the lot with my new Prius the first few drives I was like Wth and disappointed with the results. It definitely takes some getting used to the car to get good results.

Also, hills will hurt your results. We live on top of a big hill and coming home it always knocks a bit off the results.

 

Any car takes time to get use too. Even on it's worst day the Prius will get better fuel mileage then pretty much
anything else out there.
Just drive the car the way it was designed for and you'll be fine.

 

I recommend checking out a few videos on youtube on hypermiling. That's how I learned. There's one that's about 11 minutes long that is very informative. Learning how to use the gauges on my dash board really helped me out a lot. When I first got my car I had a few drives in the 30MPG range but I really upped my game with these techniques. I get in the 60's and even the 70s some times.

 

For what it's worth, that's about the same MPG I get on my 3-mile commute down here in Atlanta. Short trips like this can't do well for mileage. Having the AC on is also a mileage killer.

Every so often, I take the car for a weekend drive on a highway, set the cruise control to 65, reset the trip meter, and go for about an hour. As long as my MPG is over 50, I don't worry about low mpg during the week.

 

Every time a fellow Prius owner asks about his low mpg, I advise him to do the exact same thing.