2015 milage lower then 2012??

Time of year? (Gas companies change the formulation of their gas as the seasons vary) I keep accurate logs of the gas consumption of my 2009 Gen II and I've noticed the best I get during the summer months (Jul, Aug,Sep) can be ~51mpg, but in winter (Jan, Feb, Mar) it drops to ~39mpg! …but as they say, YMMV!

BTW: In the summer, the car is wearing Michelin Energy Savers (48F/46R) on 16" Alloy OEM rims, in the winter Bridgestone Blizzaks on 15" steelies (40F/38R)

Also highway driving with the windows (sun-roof) open uses more energy than closing everything and running the A/C

 

Did you check to see if the parking brake is dragging?

 

When I joined Fuelly last month, I wondered about the reasons for the different gas mileage averages for the different Gen 3 model years.

Toyota Prius Mileage | Fuelly

Summary

2010 46.4 (843 vehicles)
2011 47.1 (419)
2012 48.4 (760)
2013 47.3 (533)
2014 48.0 (254)
2015 45.1 (163)

I was expecting that the 2010s would have the lowest gas mileage of the Gen 3s because of higher mileage and maintenance issues with age such as clogged EGR systems, but the 2015s are the lowest. What are the differences between model years that could make a noticeable difference? I know the intake manifolds changed many times - probably a lot of other little things too. Is there a noticeable break-in time that might cause the low average for the 2015s?

 

Good catch:

Before drawing any conclusions about the 2015, it makes sense to plot the distribution of MPGs. The reason is I've seen a bi-modal distribution in the early 2010 data suggesting there are two, distinct groups of Prius owners and driving styles. Also, it helps to have at least a full year after the model year, to even out climate and terrain effects.

Given the model year starts in the Fall (I suspect), the cold-weather, early purchasers would have more entries than the Spring purchasers. Given the 2016 went on sale in the middle of February 2016, take another peek at the data in February 2017 to ensure a full operational year of the 2015 model.

Personally, a 2015 would be a better buy compared to our 2010 if only because all known factory improvements are in those cars. We have a 2003 Prius and it has been relatively trouble free compared to the 2001-2002 models.

Bob Wilson

 

how many miles have you put on her, how many tankful's, and how are you calculating mpg's?

 

My 2015 is one of the higher-mileage ones on Fuelly, but you will see my mileage get (rightfully) decreased by cold winter temperatures and winter grade fuel. I have not blocked my grill, and I drive in "Normal" mode around 100% of the time.

I believe bwilson is 100% correct that there are lower 2015 Fuelly mileage averages because:

1) Many eco-focused early adopters have already purchased or have moved on to Teslas/Leafs/Volts/etc.
2) Gas is much cheaper nowadays, decreasing the financial benefit of sensible Prius driving techniques
3) The "lame duck" 2015 was a tremendous value with large discounts from MSRP (over $4K for me) and 0% financing, attracting "value" shoppers who weren't willing to pay a hybrid premium in the past
4) A significant portion of the late-purchased 2015's have had a full winter, but not a full summer.

He is correct that a 2015 is a great deal because of all the factory improvements helping reliability. Also, late model 2014's and 2015's have the chassis stiffening that improved small-overlap crash test ratings from "Poor" on the 2010-2013 to "Adequate" on the late model 2014's and 2015's. (see
Vehicle details
)

 

Yea, I thought they'd never leaf. <grins>

Bright people, they were sometimes a little "Type A" about 'you must pulse-and-glide; you must feather the throttle, and; Release the Gertes.' Now they've self-selected to EV technology where such nonsense becomes redundant. In contrast, our quirky Prius control laws provide no end of amusement . . . and 3x to 5x the range before stopping at a gas station.

Bob Wilson

 

My bet is the tires. we are comparing new tires (maybe not even LRR) with old used LRR tires that have better efficiency.
prius is very sensitive to tires. i went from used ecopias to new continentals (supposedly LRR) and my MPG went from near 60 to low 50's overnight. i still average near 50mpg 30,000 miles later. same commute.

furthermore, the OP didn't explain if he went from 15" tires to 17" or not.

 

I'm getting average commute of 44 mile at 60 to 70 mph mixed highway and city of average of 56 mpg or more...

Posted via the PriusChat mobile app.

 

could be multiple reasons. close your windows, use ac, the cooler the battery the better performance. don't slam the gas pedal, speed up coast and speed up again.. give transmission a try.. coast instead of breaking often.. use better gasoline, costco by me went great fuel to crap in the past few weeks. use premium to clean out every couple tanks, I do 1 premium fill for every 20 regular fill ups.

Posted via the PriusChat mobile app.

 

What was your testing methodology for this mileage comparison?