Good deal! The 119.5 MPG round trip is much closer to realistic values. Toyota claims the NHW20 is at least 10% more efficient than my NHW11 and "119.5" matches expectations and data.

As for our good friends, the newbie Prius drivers, using a minimum cruise control speed, 24 mph, over a flat loop is an easy way to get pretty high numbers. They can reproduce this test and quickly see that 'the car ain't broke.' Sometimes, maintenance items like tire pressure, oil level and others may need to be fixed. Once they know the car can be mastered, it is a lot easier to work on driving, route planning and other advanced techniques.

Bob Wilson

 

I just have a very idiotic question.

Why do we have to jump through all the hoops, and tons of experiments to get the "claimed" MPG for Prius ?

I understand the claimed MPG might be screwed due to unrealistic testing devised by authority. However, my 98 Accord, it listed 23 City 30 Highway MPG has been very accurate ever since day 1 I got her. Even after more than 9 years of ownership, she delivers 23 for City 30 for Highway regardless which brand of gas she is filled up.

Unlike the 2007 Prius I got, I understand it's still new, only with 500 miles so far, but my husband and I have been learning and practicing all the tricks. Woody is still about 44MPG for this 2nd tank so far. Far cry away from the claim 60 City 51 Highway.

So the simple question comes down to, if the testing MPG is unrealistic, what's the most accurate MPG for Prius without all the hoops nor new driving techniques ?

I am just really curious...

 

There are two parts to the question but first the easy one. The original EPA tests were put together in the early 1970s, a time when many speed limits were lower. Thus the average "City" speed is in the 20 mph range and the average "Highway" speed is 48 mph. Also, back then air conditioning and automatic transmissions were not standard. Unfortunately, no one upgraded the EPA test methods over the years so it became more and more disconnected from real-world performance. Worse (or better depending upon your point of view,) the Prius hybrid electric excels in the 1970s test.

One of the 'hoops' suggested is to drive using 1970s style speeds and options. Then a funny thing happens, you get equal to or even better than EPA performance!

The EPA has upgraded their test methodology an in September, the cars will have new window sticker EPA numbers:

http://www.epa.gov/fueleconomy/
http://www.fueleconomy.gov/feg/ratings2008.shtml

The second, more complex answer, has to do with the physics, the way the car behaves. It would be possible to make a few simple changes that would substantially improve MPG but they would hurt other areas. The Prius seeks a balanced solution so to achieve higher performance, many of us have been testing and making subtle changes including the way we drive. For me, it is an engineering exercise and an entertaining hobby.

One proposal is to have a "mode" switch with a "performance" and "efficient" setting. If you hit "performance," the car would have a little more zip and less fuel efficiency. But if you hit "efficient," it would drive and behave quite differently.

Bob Wilson

 

However, a quicker answer is the new EPA ratings. 48 city, 45 highway. About what most people get in a Prius. Funny how "correct" testing methods can fix problems.

I find it fascinating how I can regulate what is powering my Prius down the road with gentle and careful control of the accelerator pedal. I can get the ICE to shut down (below 70 km/hr) and run on battery, coast, or regenerate, depending on how hard I press. Much more fun than the anti-Prius I traded in (2001 Pathfinder).

I can easily "pulse and glide" in the city, but I wouldn't do it in heavy traffic. I am amazed that in this city of pickup trucks, SUVs, and mini-vans, all in a hurry, that I can actually "keep up" with them while using the mileage extending tricks. They don't even get fed up with me, staying behind when they could pass if they like. I see 67 MPG when cruising at 70 km/hr (about 45 mph).

 

One of good articles about pulse and glide is...
http://hybridcars.about.com/od/owner...seandglide.htm

Ken@Japan

 

Just posted on another thread on this, here's the post. I find the trick to P&G is two fold.

1) Start your pulse on electric power without lighting the ICE
2) Once the ICE lights at around 20 mph, keep the RPMs around 1400-1600 ~36mpg.

This gives you the acceleration of a loaded dump truck, but sends numbers through the roof.

The glide part is easy enough once you practice. All black and your in it. You can switch to 'N' if you want to relax for foot, but remember to get back in 'D' before you brake

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