Toyota says EPA 50 MPG Now Official

Toyota Vehicles : / Toyota

Directly from Toyota Press Room.

That's 2 MPG more in the city and 4 MPG more on the highway despite the increase in the gas engine to 1.8L.

 

AutoBlogGreen also has a new article on the 2010 Prius which mentions the official 50/49 fuel economy numbers.

Prius 2010 detail overload: will get 49 mpg highway rating; 100,000 sales predicted for 2009

It's a multi-page article with loads of details (some old, some new):

 

Let's see, 87 MPG and an 11.9 gal. (11.3 gal. usable) tank should give 1,000 mile tanks, piece of cake! Vanity license plate:

1K-TANKS
1000-MI
1K-MILES
​

Bob Wilson

 

I managed 39 on my last tank. Damned cold weather, strong winds, and highway speeds.

Tom

 

If EPA says 50. that means 55 in real driving. I get 50-52 routinely in the warmer months with my 08, 45 in the winter. With lots of short trips.

 

I wonder if the EPA MPG for the second-generation Prius was calculated through a mathematical formula, not an actual test. Basically, the mathematical formula would convert the unrealistic 60/51 MPG of the old EPA test method to the current 48/45. But obviously we know for sure that the third-generation Prius went through an actual test according to the new test method.

With almost any economy car, you can get 50 MPG under certain driving conditions, such as driving 45 MPH on the highway. This doesn't mean that the new EPA numbers are low estimates. The thing is many people end up doing a lot of high-speed driving and are not gentle on the gas. For such conditions EPA numbers become good estimates, sometimes a bit low, sometimes a bit high, but about right in the ballpark. Of course, MPG freaks will do anything to get more MPG, even at the expense of being honked for driving 45 MPH on the freeway or accelerating to 0 - 60 in 60 seconds. Not the healthiest obsession for sure.

 

Great article. One of the better summaries on the 2010 Prius. Thanks.

 

The 2008/9 EPA stickers should be the weighted average of several tests. What is it, 3 additional tests were added in 2008?

Personally I'd like to know the pre-2008 Highway figure, as that has been my benchmark for several decades.

 

It appears that the EPA numbers 48 city/45 highway/46 overall for the second-generation Prius are not real test results, but calculated using some formula.

Old-test numbers: 60 city 51 highway

Plug these numbers into the EPA old-to-new-test converter:

2008 Fuel Economy Tests

The result is 48 city 46 highway, which is the same within roundoff errors (EPA rounds off the numbers released to consumers to whole numbers) as the EPA sticker for the 2008 - 2009 Prius.

This strongly suggests that the EPA numbers for the second-generation Prius are not actual test results.

This means when we compare the second-generation-Prius EPA numbers to third-generation-Prius EPA numbers, we are comparing apples to oranges! The second-generation Prius could have scored higher than 46 MPG overall if it went through an actual new-method test, or it could have scored lower.

The bottom line is that the third-generation Prius is not necessarily 4 MPG more efficient than the second-generation Prius -- could be less or more than that. We will know the actual MPG comparisons only when Consumer Reports tests the new Prius. The second-generation Prius scored 34 city 47 highway 42 average for the Touring and 35 city 50 highway 44 average for the base version.

 

Hi Gokhan.

If you plug in 63 City, and 55 Highway (old EPA) into that calculator, you get 50 City, 49 Highway new EPA (3rd Generation Prius rating). There might be other solutions. The 2nd Gen Prius on the old EPA was 60 City and 51 Highway. So, that is a 5% improvment City, and 7.8 % improvement Highway. Its too bad they had to increase the power. We could have seen 10 to 15 % on the City mileage.

I use the old EPA rating, because that is what I get driving my Prius when not using hypermiling techniques, in summer weather, without the AC - about 57 mpg in combined traffic. This is with a 56 mph highway speed, and just careful driving not to come racing into a red light. Which is what the old EPA rating was. So, for my driving enviroment, the new Prius improvement is going to be about 6 %. Or 60.4 mpg. Which I can get easily using hypermiling. My hypermiling summer fuel economy is around 64 mpg.

 

you might be right

At first, I was going to post the opposite, but I think you're right.

If you go to Download the Fuel Economy Database and download the 2009 datafile, you'll see an entry for the 09 Prius containing the 48, 45 and 46 mpg figures.

The above web page states:
"*The data included in the Department of Energy's Fuel Economy Guide are the result of vehicle testing done at the Environmental Protection Agency's National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Michigan and by vehicle manufacturers themselves with oversight by EPA."

Then, I noticed in the very last column (AE, if you import into Excel), there's a column "5C CODE" and it says DERIVED for the Prius and for the MAJORITY of vehicles listed there. A few others have "5-CYCLE" which would corresponding to the now total of 5 test cycles per Fuel Economy Test Schedules.

 

ehm, all EPA tests are done the same, in lab conditions, using formulas. In fact, I would say they are a lot more indicative of anything compared to CR report which is basically someone driving the car and reporting their info (which can be very different depending on many criteria).

And no report will tell you as much as single test drive

 

Actually, I want to know the pre-2008 Highway test figures for the 2010 Prius and Insight.

The old highway sticker was 78% of a certain EPA prescribed dyno test. My ancient Accord had to test out at 38 or 39 mpg to get its original sticker of 30, downgraded to 28 on the new system. But I was able to average 35 most summers, and broke 39 on a few trips, and its lifetime average (including city and winters) exceeds its original highway sticker.

My less old Subaru couldn't beat its EPA sticker until I learned to hypermile last summer. Then it jumped to 95% of its dyno test.

The new system weights in additional tests, lowering the number. But I still want to use the old dyno test as my target.

Based on a variety of comments, I have a feeling that some of the factors that normally drag down new EPA numbers have been improved in the 2010 Prius, and that some of the modes used by hypermilers are now programmed in. Though both would be excellent moves, it would also mean that it will be harder to stretch fuel economy above the new EPA sticker than it has been for past models, both hybrid and traditional.