EPA Vs NEDC
 

We all know that US EPA figures are much easier to beat than European NEDC figures.

This frustrates those of us who own cars that were never EPA rated.

EG: Honda Fit/Jazz 1.5 CVT 36mpg (6.5l/100km) combined. NEDC 4.5l/100km or 52MPG US :eek:

A quick look in the garage finds that the best Fit (an older model) is only just breaking 52mpg. I don't know how badly you'd have to THRASH a Fit to only get 36mpg.

Now my my current daily is a 1.6 Renault, rated 9.7 city. Doing all city driving with a payload up to 800kg (~1800lbs) it's running 57% over NEDC.

If I consider the Jazz example, there's a 44% difference between NEDC and EPA.

Now if I multiply my NEDC figures, 9.7 becomes 14l/100km. That would mean my best tank of 6.05 was 130% over. Even the current tank which has been 100% with 800kg payload, would be sitting at 75% over.

So am I a hypermiling god or are you guys just not trying?

Are those U.S. gallons used in those miles per gallon figures or Imperial gallons?

Our ethanol mandate hurts some, I doubt anybody is running ethanol free gas except the EPA which says they adjust the sticker down 1.5% because of that. From the EPA webpage, "EPA adjusts the fuel economy label estimates downward by about 10 percent to account for a variety of factors that are not currently accounted for during laboratory fuel economy testing, such as tire under-inflation, wind, hills, and road conditions. It also includes a 1.5 percent downward adjustment to account for the average national ethanol content."
Your 34.9 mpg in a 2014 1.6 L car doesn't seem all that great to me but if it is all city with a payload then that's pretty good. Then again a city in WA like say Perth at the worst is probably much better then a warm city like LA with bad traffic. I would say it's more like Vegas or Phoenix, where I bet some pretty good city averages can be found. I get about 28 mpg all "city" summertime with a 2002 2.5L AWD Forester which drops to 23 in the winter. I don't really try, especially with gas at $1.75 a gallon like it is right now. I think bottled water costs more, glad my car doesn't run on that LOL!

All US Gallons.

European fuel contains Ethanol too.


I parked my Renault next to a Range Rover and took a photo from overhead, it wasn't that much smaller (unfortunately my SD card crashed). My average speed in peak hour can struggle to beat 10mph. My tank averages under 20mph, most days I don't get to go over 40mph. It might be a 2014 model, but the engine dates back to 2001. Closest thing you can get in the US is the Ford Transit Connect, rated 22mpg (10.7l/100km) City (a more modest 10% discrepancy - but it uses a modern DI engine and the auto might be 'helping').

You guys seem to have massive roads that when I watch the odd YouTube, usually have next to no traffic on them, even suburban roads seem to have a massive capacity. Nothing like that exists in Australia, infact much of my commute is on a single lane road, because the other lane was converted to a peak bus lane...

http://usa.streetsblog.org/wp-conten...1-1024x651.png

My broader reason for starting this thread is to compare peoples EPA vs NEDC vs real world results. I could Google them up myself but owners are better positioned to know if their cars are the same in Europe Vs USA.

I know the Toyota 86 is the same around the world so 25mpg EPA vs 7.1 NEDC or 33MPG. So a 30% difference.

The lower speeds make the size and aerodynamics meaningless at least. My sweet spot is around 35 mph as the forester has low gears and bad aerodynamics. Just fast enough to idle around in 5th gear.
I've been to Perth which seemed to me exactly like any US city, that was back in 1998 so maybe they haven't kept pace with growth but back then the roads seemed pretty easy.

Size = Weight. I'd argue that engine size is more meaningless (bigger engine = shorter pulse - within reason). Besides at ~30mph aero drag is already at 50% of total drag, far from meaningless.

My point isn't really about my city vs 'your' city etc. It's about how beating the EPA figures really isn't an achievement. Avg speeds are a decent way to compare traffic density but they're rarely posted. When ever I post economy numbers on other sites I get excuses - one guy told me that in London he sometimes averages 10mph, well that's why I do in peak hour - I was a bit surprised London isn't worse. There's a point at which people just give up on driving - most cities reached 'peak traffic' in the 90's.

I possibly do have the worst 1.6 on this site (edit: had to check - I don't :)), but it's no doubt one of the best (up to) 5000lbs vehicles was well (tested CD at 0.45), and beating the NEDC which most cars on here with hypermiler status don't. Even with 5000lbs I'm matching/ beating the EPA of things like late model Focus and Civic. Is the EPA too easy to match/ beat?

But then I look at my poor little UFI struggling to match NEDC combined, yet he's still in 26th on this site. In fact he's the only car in the top 50 with a negative in front of his 'EPA' (NEDC) figure. As a point of referance the second best Fiat 500 on here is a US 1.4, running 44MPG which is 34% over EPA, while my 48MPG is -20%.

I just wonder if having an agreed multilpier for NEDC rated cars would help spur interest from more Europeans, or at least NEDC on the labels on the garage and signature tags.

I understand your point, but being different tests, there's no direct comparison.

As an example, the 1997 1.8 Mazda Protege (the figures I use for my Astina), rates 23MPG city in the US and rates 26.13 in Australia, 13.6% higher.
The same car rates 29 MPG highway in the US and 36.75 in Australia, 26.7% higher.
Which percentage would you use?

Because the test method is different, different engine/transmission combinations would probably produce different percentage variations even within the same model.
There's probably no "one size fits all" multiplying factor that can reasonably be applied. :(

Some Googling suggested a 20% difference on average, but of course there will never be a solid figure. You would of course use the average of city and highway ,which conveniently, is around 20% based on those Astina figures. It would never be strictly 'fair' but neither is using the NEDC numbers.

But I think I have a semi-solution, change the required percentage to claim 'hypermiler' for NEDC rated cars, that way we're not trying to compare apples to oranges, but just changing what we consider a 'good' result.

Perhaps simply matching NEDC should be enough to get a 'hypermiler' tag.

Or one easier solution: just keep satisfied with your skills when you beat NEDC (as am I) and if you want, change your personal rating (lurker, master acomodder etc...) to "NEDC hypermiler". (which I probably would)

Or hopefully our great and smartwise EU administrative will make more realistic tests ( which I doubt).

EDIT: Just stroke me: mikeyjd here on ecomodder is doing vacation in France (thread here: http://ecomodder.com/forum/showthrea...nce-34165.html ) and back in the U.S he is doing some good hypermiling (much more MPG than EPA rating of his cars), and he has rented Renault Trafic (according to the thread), with NEDC rating 5.6 l/100 km. So now we just need to wait for results. I know it is not scientific testing, but at least it can answer how hard/easy is to beat NEDC