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-   -   Should there be a new EPA rating City/Suburb/Highway (https://ecomodder.com/forum/showthread.php/should-there-new-epa-rating-city-suburb-highway-9950.html)

drewwitlin@hotmail.com 09-02-2009 04:58 PM

Should there be a new EPA rating City/Suburb/Highway
 
I drive primary in the Suburbs, it is way different then actually driving in a City, and doesn't have the benefits of the Highway.

City has traffic lights every block, its congested or gridlocked, speedlimits 25-35 and pedestrians.

Suburban is traffic lights every half mile or more, easy to predict the flow of traffic, speedlimits in the 40's

Just a thought, comments?

Frank Lee 09-02-2009 05:05 PM

It's complex enough already.

Cover the "typical" worst case and best case scenarios, add an "average" value, and let the viewer decide where they fall into that scheme.

jkp1187 09-02-2009 05:39 PM

I'd argue for getting rid of the combined value - it assumes everyone drives a certain city/highway mix.

RH77 09-03-2009 01:23 AM

First, the "City" cycle needs to be more aggressive. Compared to the European circuit that includes the intermediate "Suburb" or "Ex-Urban" cycle, our City value allows cruises that are too long in duration.

Several times I've wanted to test a vehicle for an FE report, and ended up getting stuck with city-only driving and crummy FE. Indy and San Antonio were prime examples. Try driving in stop-and-go situations, at slow speeds, repeatedly and get that number the EPA reports (EcoDriving techniques removed).

I agree that the the 3-Part result would really show people how much city driving hits FE, and how high-speed operation would perhaps hit FE vs a smooth, 45 mph parkway cruise in the 'burbs. The "new" EPA test (that replaces the decades-old version), is still old-school.

RH77

cfg83 09-03-2009 02:26 AM

drewwitlin -

I would keep the current EPA standards, but issue reports of fixed-parameter steady-state test cycle results, like idle GPH (+-AC), MPG @ 35 MPH in gear X, MPG @ 55 MPH in top gear, etc, blah blah blah, ad nauseuam. This would allow people like us to predict the potentials of OEM drivetrains. Also that BSFC map. That should be in the report too.

CarloSW2

Doofus McFancypants 09-03-2009 08:09 AM

The issue with any static number (City / highway / other) is that the assumed driving schedule is confused with the numbers. Just look at all the car commercials touting the HIGHWAY mileage for the cars. Maybe the Chevy Traverse goes get better highway mileage than a CRV - but when is the last time someone spent MORE TIME on the highway then off the highway? I am sure it is in the single % of the total population.

Those who do not want to really understand will never GET IT.
But i do agree with Carlo - those that get it would greatly benifit from the DATA of speed / gear / consumption..

For the Informed consumer - the more data the better.

gone-ot 09-03-2009 10:16 AM

...I suggest the '2/3's of Clint Eastwood' approach: just GOOD(highway) & BAD(city), the UGLY(in between) you can "guestimate" based upon your own situation.

...I do about 90% highway and 10% urban, but wife is 40% highway and 60% city...just depends upon who's driving.

wagonman76 09-03-2009 12:31 PM

Quote:

Originally Posted by jkp1187 (Post 125504)
I'd argue for getting rid of the combined value - it assumes everyone drives a certain city/highway mix.

I agree on that totally.

There are just way too many scenarios to try and add any new ratings. But I would like to know how they come up with the ratings. What is city? LA rush hour? Or something a lot better? How about highway? Long easy cruise at 55? Or a crowded freeway at 75?

At least that way you could get an idea as to how YOUR typical scenario compares with the ratings.

I am one who spends more time ON the highway than off. I would think that would be similar for most people who live in rural areas and have to drive forever to accomplish what needs to be done.

MetroMPG 09-03-2009 01:17 PM

Quote:

Originally Posted by wagonman76 (Post 125623)
There are just way too many scenarios to try and add any new ratings.

Strongly disagree!!

While I think adding another "let's see if we can simulate another trip to grandma's house" kind of test would be pretty much useless, I'd very much like to see "pure" data as Carlos mentions.

EG. a chart of fuel economy plotted every X units from 50-120 km/h (30-70 mph) in top gear would be excellent for evaluating the efficiency performance of different vehicles.

Such as: http://ecomodder.com/forum/showthrea...05-a-9841.html

http://ecomodder.com/imgs/graph-speed-mpg-corvette.gif

Quote:

But I would like to know how they come up with the ratings. What is city? LA rush hour?
Here's how the EPA test cycles work:

CITY:

http://www.fueleconomy.gov/feg/images/ftpdds.gif

HWY:

http://www.fueleconomy.gov/feg/images/hwfetdds.gif

They've twice added "fudge factors" to the actual numbers obtained from these test cycles. Also there are other, newer tests plus more detailed information about the above, here:

Fuel Economy Test Schedules

shovel 09-03-2009 02:51 PM

An old guy I used to hang out with (inherited friend when Dad passed on) had a saying for every occasion.... and one of his favorites was "Nothing's ever been so simple that some fool couldn't make it more complicated."

The two-figure, "city/highway" is great. it shows best typical and worst typical in a way that everyone can relate to, and everyone can decide where they fit on a one dimensional figure like that.

It's kinda like how engines are rated as horsepower and torque... we know that horsepower IS torque with the factor of time included.. but by seeing both figures we can get an idea - RAPIDLY - in our head of how the engine behaves. Low HP number and high torque number? It's a stump puller... high HP and low torque? Zippy. Instant understanding.

That is what I think is valuable about the city/highway two-measurement system. The actual numbers don't matter because everyone drives differently from each other - but when you see the two numbers you instantly understand what they mean to you.


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