Why the sudden drop in our 2012 Prius gas mileage?

Asked by May 25, 2014 at 04:56 AM about the 2012 Toyota Prius Three

Question type: Maintenance & Repair

The MPG on our Prius recently dropped from 52 to 44.  The drop occurred shortly after we took the car to a dealer for the software related recall fix.

15 Answers

222,985

There is your answer. But some owners who had the recall done reported no change to some saying their MPG dropped. I guess it's how you drive if your going to notice such a thing. Open this link, it will take you to some Prius owners who did the update.....http://priuschat.com/threads/who-has-done-their-recall.137632/

10 out of 10 people think this is helpful.
105

I had my 2012 Prius in for the recall and after the reprogramming there was no change. Where we have seen change is if the weather is cold (below freezing) and if it is raining (water on road seems to effect mileage) .. If driving habits are the same - and these two did not occur - I would take it back to dealer.

30

I had our 2010 Prius Two for software recall in June and noticed a drop in MPG from about 48 - 50 mpg to, at its lowest, about 38 MPG. Brought it back to dealer the other day who, after checking it out for two hours, did not acknowledge any problems, Since then, I have gotten from 50 to 55 MPG. Go figure.

3 out of 3 people think this is helpful.
260

My 2011 prius - had oil change synthetic as recommended, immediately my mpg dropped fro 50 to 47/47. I can't get it back to 50. What could cause that drop. Bill

22 out of 22 people think this is helpful.
50

I finally took my 2011 in for the recall last month. I went from 40 MPG (highway with a lead foot) to 33 MPG. Glad to see I'm not alone.

4 out of 4 people think this is helpful.
260

So what caused the big drop in mpg? My dealer suggested: increased ethanol in gas, low tire pressure, weather. He opposed an y possibility of computer problem. Suggested I buy my gas elsewhere, maybe mid-grade for a few fill-ups. I'm still bewildered. ,

4 out of 4 people think this is helpful.
50

I checked my oil last night and it looks like they put too much in when I took it in for the recall and oil change. Hopefully, the extra oil is the culprit. Hoping to make it to service today to get rid of the extra oil.

1 out of 1 people think this is helpful.
40

Our 2012 prius gas mileage dropped 8 to 10 miles per gallon after the recall also. It's not the gas it's not the oil, it's the software update.I drive 200 miles a day same route same speed and have the recall over a month now have a months worth of data I'm taking it back to the dealer.

4 out of 4 people think this is helpful.
70

I can say the same my 2012 prius has 99,000 miles on it. Before update 47.5 highway I run about 80mph After, no matter how I drive I can't get above 40. Defeats the purpose of the car with this milage. Had computer data and more, presented to dealer, they said there is nothing they can do. Even after acknowledging in writing the update may have affected my milage. I won't buy another one, that is for sure

4 out of 4 people think this is helpful.
70

Oh and I've tried everything. Non ethanol gas, k&n air filter, new tires, etc. None of it worked

1 out of 1 people think this is helpful.
50

My drop to 33 mpg turned out to be a combination of Firestone putting too much oil in during an oil change and they decided to underinflatey tires. After that, I started getting 40 mpg again. Are y'all using the dashboard's mpg or are you calculating it the old fashioned way?

70

Jimine I did it the old fashion way. Filled the tank 24.00 aka 10 gallons and drove it till 0 365 miles on the tank

2 out of 2 people think this is helpful.
10

Priuschat also ha a thread on this

1 out of 1 people think this is helpful.
60

I have a 2010 prius and up until the past 3 months I been getting 45-49 mpg. Tapered off to 42-45 mpg now im at 39. Car has 160k miles now. Checked the tire pressure F39 R34. I do my own oil changes 0-20 mobile 1 so I know that there is the right amount. Gas 89oct and didn't matter what brand of gas I used in the past. Wondering if it might have to do with the winter blend gas? Thing is I have never got below 42 with a roof carrier on top.

6 out of 6 people think this is helpful.
10

Anyone still on this thread? I just experienced this problem on my 2012 a couple of months ago. After I had read this thread I checked my oil and WHAT DO YOU KNOW it was overfull. I have been crazy and insanely busy with medical school stuff but have had some time to breathe recently and realized that I've been getting 44mpg at best if I limp the car around town. Just changed my oil today and will be hanging onto the fifth quart. The last business that changed my oil may have overfilled it. Tire pressure is fine. I have also read that my 12V battery may need to be replaced? Does anyone have any other suggestions? I also just replaced my air filter and plan on replacing my spark plugs soon. I'm moderately annoyed as I could achieve 48- 60mpg easily and I'm not sure I've hit 45 in a couple of months. I've also experienced five or six seizure like episodes with the car. I lost all power and there is no liner connection between the accelerator pedal and whatever kind of madness the planetary gear set and powerplant are doing. I'm assuming this relates to the recall aforementioned. I was not able to safely drive the car as it was violently lurching like an auto transmission was exiting your vehicle, so after restarting the car it fixed itself. I at first panicked and thought that I was losing my transmission. Have done the whole on and off again thing for the subsequent encounters. Super annoying actually. I'm looking to buy a Subaru soon!

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

Prius

Looking for a Used Prius in your area?

CarGurus has 22,368 nationwide Prius listings starting at $1,250.

ZIP:

Search Toyota Prius Questions

Toyota Prius Experts

#1 raae
raae
Reputation 600
#2 TupeloMS
TupeloMS
Reputation 550
#3 jrdregs
jrdregs
Reputation 380
View All

Related Models For Sale

Used Toyota Camry
1,094 Great Deals out of 96,265 listings starting at $1,250
Used Toyota Prius v
37 Great Deals out of 4,623 listings starting at $7,200
Used Honda Civic
668 Great Deals out of 77,419 listings starting at $1,000
Used Toyota Corolla
868 Great Deals out of 74,427 listings starting at $1,500
Used Toyota Prius c
58 Great Deals out of 5,472 listings starting at $5,888
Used Honda Accord
814 Great Deals out of 81,613 listings starting at $899
Used Toyota RAV4
644 Great Deals out of 61,987 listings starting at $2,450
Used Toyota Prius Plug-in
8 Great Deals out of 489 listings starting at $8,790
Used Honda CR-V
813 Great Deals out of 59,368 listings starting at $1,200
Used Chevrolet Volt
19 Great Deals out of 5,152 listings starting at $5,000
Used Honda Fit
136 Great Deals out of 21,475 listings starting at $2,900
Used Toyota Yaris
89 Great Deals out of 13,105 listings starting at $1,745
Used Mazda MAZDA3
231 Great Deals out of 28,937 listings starting at $895
Used Ford Fusion
1,056 Great Deals out of 78,455 listings starting at $1,250

Used Cars For Sale

2017 Toyota Prius Three For Sale
1,724 listings starting at $24,532
2016 Toyota Prius Three For Sale
364 listings starting at $20,995
2015 Toyota Prius Three For Sale
4 Great Deals out of 139 listings starting at $11,999
2014 Toyota Prius Three For Sale
11 Great Deals out of 283 listings starting at $9,998
2013 Toyota Prius Three For Sale
13 Great Deals out of 282 listings starting at $8,998