FuelEconomy.gov official ratings posted - 58 City/53 Hwy Prius Eco - 54 City / 50 Hwy for Prius

I'm sure that is true. I routinely bettered (calculated, not indicated) the EPA figure with my 2010. But we all know that fuel efficiency is a very elusive figure. Each of us could achieve vastly different numbers even if we were to drive the same car. Environmental impacts, load, tires and driver habits are all such major factors.

I could never understand why Consumer Reports could not do better. If I recall correctly, they always showed a 44 mpg (combined).

 

I also suspect that the programming may be a little different but it could be in areas other than CVT - transmission.

Why do you think that the tires would make no difference in the EPA tests? Wouldn't the roll-down (coastdown) test results reflect tire characteristics and in turn effect the calculated EPA mpg's for both City and Highway.

 

It has to do with the 'revs/mile'. Resize your next set to be 4% fewer miles per rev and the problem is solved.

Bob Wilson

 

I find all this speculation and concern of mileage for the different models interesting.

Don't all of you know the govt., both Japanese and US, mileage "estimates" are -calculated figures-, based on many variables and measurements. The weight does factor into the calculations, and apparently not accurately. Gee, what a surprise!! Oh, and the "EPA" tests were done by Toyota or their hired company, and submitted to the EPA, AND, the Japanese and EPA tests are completely different in method and result.
DO note they include the statement, something to the effect of: "your mileage may vary from the published figures". Very famous now, as YMMV! Again, gee what a surprise!
They also include the statement "numbers displayed are for comparison only". Please, apples to apples!

My GII (Pearl) got very close to the displayed mileage, but only at certain times of the year.
My GIII (Pearl S) gets poorer mileage than displayed, but at least it's consistent!

Oh, and the Canadian test methods WERE ridiculously in error. There is NO WAY you could consistently achieve figures like 3.4 l/100km. Unless you always drove downhill. Pearl S averages around 4.8 without any attempt to get "good mileage". I drive, I don't mess around with other traffic.
I think they "improved" the Canadian methods. But we'll see.

 

Yup, it actually says "will vary".

 

well of course, how could it not?

 

Weight and tires can make and a difference. Just bumping the pressure of the non-Eco tires to the Eco's will improve it. Before the actual EPA test cycles are done, a coast down test is performed to determine the road load to program into the test dynanometer. It is done starting at 50mph, but the new Prius might be done at the new rules of 70mph, and how long it takes to decelerate is measured. Not a direct measurement of weight, rolling resistance, aerodynamics, but they do impact the result.

The lighter weight, slightly better aerodynamics. and tires with less rolling resistance than the stock, which are also inflated higher to further increase that difference, mean the Eco will have to fight less resistance from the dynanometer during the test than the other Prii did.

It includes full tank along with all the necessary fluids. I think there is a dry weight without them that can be reported, but that might be used more with aircraft or boats.

Canada just uses the EPA tests with units converted. They are just finally adopting the changes the EPA made in 2008.

 

Hasnt this always been the argument people use to say the Prius isnt worth buying? The base msrp for a Corolla is 7K less than a base Prius. At the corolla's 35 mpg it would take 350K miles to make up the difference in cost.

 

exactly. prius isn't about saving money with low gas prices, it's a lifestyle.

 

The problem with Consumer Reports is a wacky city MPG rating like 33 MPG. On Gen3 CR gets 55 MPG on Highway. So the average is low. The only good thing is CR seems to hit all hybrids with a wacky low city MPG.

 

My experience has been the annual Prius fuel savings covered one month's car payment each year, ~8%. Once the Prius were paid off, the fuel savings have continued even to today. Then there are gas stops not taken:

• +500 miles - 2003 Prius
• +600 miles - 2010 Prius

Both Prius remain interesting puzzles. So Saturday I drove around town with miniVCI recording engine metrics so I can plot BSFC vs ICE rpm. I also included vehicle speed and EGR valve setting because these things interest me.

Ordinary gas cars are boring and EVs, no mystery there. Then occasionally I apply what I've learned about the Prius to a driving stunt:


Prius have been anything but boring and attract professional and amateur trolls around come to amuse us. And every now and then, someone wanders in 15 years after the first Prius to 'reveal' Prius don't save enough in gas over some piece-of-sh*t car.

What these 'accounting' idiots don't realize is some of us are just another kind of gear-head. Some of us are the sailplane owners and pilots of the road. We really don't care any more than someone who gets a 'leather' interior or a fancy audio system. Since when has car 'bling' payed off?

The Two Eco is a new puzzle and I'm looking forward to getting some metrics and data. With TSS(P), it will someday be a handy ride. Of course I should look around to see if anyone is selling a 2015 with the advanced package and a deep discount. <GRINS>

Bob Wilson

 

Yup it's called the hybrid premium and it's a slippery slope. One could say buying a used corolla has an even better cost/mile ratio over a new one. Or a bicycle. Or public transportation or.........

But in this case, it really is an apples to apples comparison as the '16 Prius/Prius Eco are nearly 100% identical.

 

Are you really saying that the Corolla is now nearly 100% identical to the Prius?

Before I bought my Prius I had rented a new Corolla for a week while on holidays. Let alone not being in the same class, it wasn't in the same league.

Now since then, the Corolla may or may not have improved greatly and many of its shortcomings compared to the Gen 3 may been fixed but so far as I'm aware, there is no Corolla hatchback available in North America.

The Corolla may be a sensible choice for many people but to say its almost identical to the Prius does not seem even close to correct.

Even the 2015 Prius is not nearly identical to the 2016 Prius.

 

No, you're confused so I edited that post. The original comparison of purchase price vs fuel savings was '16 Prius to '16 Prius Eco.

 

no, it's not even close. you have to look at the post he was quoting.

 

You could also include 'buying last model year clearance' versus the latest hotness. Still, we've seen these claims over the past 15 years. Because of the model-year changes in progress, we'll take a rain-check on this:

More than just the Prius and Corolla are going through model-year changes and the details needed for a comparison remain sparse. In about 60 days, the last of the embargoes should be over and test articles available at the dealers. But we can predict the Prius will have superior City MPG over everything but the plug-ins that have their own plug-in premium issues.

Bob Wilson

 

Here are the official fuel-economy numbers from the EPA site displayed side-by-side for easy comparison. I think that the main difference of Prius Eco is a different CVT program (at the expense of acceleration). This is in addition to small MPG-enhancing features such as omitting accessories to reduce weight (at the expense of convenience, especially with a blown tire, and at the expense of higher price of a lighter Li-ion battery, additional cost of which is offset by omission of some accessories) and using skinnier tires to reduce rolling resistance (at the expense of handling and ride).

 

Just a reminder, there were pre-2008 EPA set of numbers:

	Model	City	Combined	Highway	User (cnt)
1	2001 Prius	52	48	45	44.9(26)
2	2004 Prius	60	55	51	47.4 (91)

Not knowing any better, I keep getting 52 MPG both City and Highway in our 2003 Prius.

Bob Wilson