Why my mpg does not match promised values?

I believe that WLDP is adoped by at least 55 countries in the world in it's original form - including China, Japan, South Korea, Russia, India, some non-EU countries with modifications. Hence the name "World ...". It seems that the USA hasn't yet adopted it, but will be in some form - but might call it something else??:

"and the USA, are currently in a monitoring position and have not yet communicated any implementation timeline"

 

U.S. adopt someone else's idea? Have you ever heard of the 'metric system'?

Right now we are pulling out of treaties and agreements much faster than we join them, and killing more old regulations than creating new ones. So until something changes, I believe we will be on the timeline known as 'never'.

 

Yes, I well remember, when at school in the '60s there was talk of Aust moving to metric - which happened. It certainly is much more logical. Then a decade later, not long after we converted, I read (Popular Science or Mechanics?) that USA was going to follow, and Congress had approved it I think. Maybe one day. Last I heard, there were only 2 other tiny countries which didn't adopt metric.

Metric now has a new kilogram. Or at least a new way of measuring it.

 

Yes, in the 1970s, we were very much on track to Metrification. I remember some speed limits in km/h and distance signs in km posted near home, as tests and initial acclimatization steps.

Then in November 1980, Ronald Reagan was elected President. The End (of metrification, budget responsibility, and various other things).

 

The only "advertised" mpg is the EPA estimate, which is just that, an estimate. That test is done under defined conditions on a dynamometer, not actual roads and not in cold weather, etc.

All the manufacturers run the same test cycle, so they are measuring under a common set of parameters. The test has some adjustments built in to estimate real mpg, but it's a guess. If you drive that cycle under those conditions every day, you will get the "advertised" mpg.

I have always been able to exceed the EPA estimates on every car I own (except my convertible, which I flog mercilessly).

 

What is your convertible?

 

2006 MX-5 with a few street mods.

 

They changed the ethanol mixture in Washington state. i struggle to get 54MPG now. I miss the summer months where 56 was my worst and 59MPG was a good tank. I keep the AC at 67-68F.

 

In Seattle?

I mostly have my AC Off, with ventilation just pushing through fresh outside air with temperature set to LO. When AC becomes desirable -- certainly not yet -- the control temperature is set at least up to mid-70s. Is there something materially different about your Gen4 compared to my Gen3?

 

When the temps outside are cooler usually my AC is 65-66F. If it was 90F outside my AC would be probably 70F. I try not to spend much time in the Prius when the temps are warm outside.

The Gen 4 is a much better Prius than the Gen 3 Prius. Better handling, better fuel economy, quieter, bigger and full color display. The Gen 3 Prius will not start up on battery like a Gen 4 Prius will. It also utilizes electric driving more so than the Gen 3 Prius. That is not to say the Gen 3 Prius doesn't get good mileage. The Gen 4 has a high upside as has been stated by other Prius forum members.

My ODO says my overall mileage is 54.1 with 28K miles on it. There are what I call professional Prius drivers on this forum. Some are pushing 60MPG tanks. My best tank was 59.8 last summer. There is an art to driving a Prius when it comes to getting good MPG. It takes practice and some have trade secrets to their art.

I do keep my AC and heat on Eco mode.

 

MG2 always starts the vehicle, no matter what Generation PRIUS it is. At least it does for Gen 1 and Gen 4 - but I haven't double checked Gen 3 - I can't understand how it wouldn't.

 

I was referring to cranking up the gas engine. The Gen 4 will start and drive without cranking up the gas motor if you have a good charge. I was under the impression that all other Prius generations start with the gas engine and switch to electric after some time.

 

I believe that the car never moves (either direction) without MG2 taking the "first step". Step on the throttle and the ICE joins the party a split second later.

I've just had a look at the Weber Auto YouTube - and he seems to say that for Gen 1 - and that's just progressed through to Gen 2, 3, 4, 5.

Start at about 16:00 and he describes the action of Gen 1 - only a couple of minutes to watch:

Here is Gen 2 - start at 5:00

Gen 3 - start at the beginning"

There's one for Gen 4 somewhere which is quite a different layout - and it's dinner time!!!!!

 

Actually it’s MG1 that starts the engine and charges the battery from the engine.
MG2 drives the wheels and captures energy from regenerative braking.

 

True, MG1 starts the ICE - but MG2 starts motion happening. And - MG1 starts the ICE at times when the car is stationary (eg to run the heater or if hybrid battery is low).

WIKI says it like this [ Hybrid Synergy Drive - Wikipedia ]:

 

I was referring only to climate control, not the other items you replied with.

But Seattle had only 11 days that reached 90F last year. While this was far hotter than a normal year of just 1 or 2 days reaching 90F, it wan't enough to have much impact on your whole summer's mpg.

If you must be running with AC turned on most of the time in your Gen4, then there is something serious about it that is not better than the Gen3.

.. very similar to what my 2010 had achieved at the same age and distance:

Note that the MPG displayed here is pump MPG, not dashboard computer MPG. The later would be a couple points higher.

 

Each state is different. Washington state used to put the 10% ethanol in the gas November 1st through March 31st. You can see that your mileage dips in the winter months. Many believe that is because it's colder and takes more energy to heat a car than to cool a car. Those with electric know that the winter months are their worst mileage months. If you want to test my opinion because it's not a theory. Find someone or somewhere that has ethanol free gas. Seal it up good and put it in your empty tank in November or December. A Prius is a hybrid gas as electric so the winter cold months of heating the car do not impact it as much as all electric cars. If you look at gas prices during the 90's and early 2000's. You will notice gas prices always went up in the spring and down in the winter. It's common knowledge that ethanol reduces fuel economy around 10%.

I don't know how much fuel my Gen 4 Prius tank holds. But I have never put more than 9.8 gallons in my Prius and fill it up between 500-550miles. Usually the pump says somewhere between 8.9-9.6 gallons.

I have central air at home. I run my AC in my car quite a bit for personal comfort rather than need. I only change the oil because the oil changes are free. That is how reliable Japanese built cars are. The Prius has been completely trouble free.

Could you provide a screen shot of your ODO with your overall MPG along with total miles driven on your Gen3 Prius? I will post mine if you would like.

 

I have not found that to be the case, and based on energy content along you would expect about a 4% decrease in fuel mileage, since 10% ethanol mix has a bit more than 96% as much energy per gallon as 100% gasoline.

 

Yes and tobacco doesn't cause lung cancer. Just remember there is money to be made putting out numbers that do not make sense in the real world. Getting rid of leaded gas was a good idea thought. But that was back in the 80's.

 

What does that have to do with the actual energy numbers of the fuel? You can do the same math if you would like, and perhaps you can show us how you arrive at the 10% number.

For a 10% fuel economy hit with 10% ethanol, the ethanol part of the fuel is providing zero energy?