Which EPA to use?
 

Right, My Saab is slowly sipping its way through this tank (apart from one or two "TUUURBBBOOOO" moments:D)

Happily its at over 230 mles and still showing over 1/2 a tank- trip comp says 300 miles + range left.

Shortly I'm going to have to add it to my garage. The 9-3 WAS available in the US so it does have EPA figures available. See below.
Gas Mileage of 2001 Vehicles by Saab

The figures seem to suggest 26/28 on Motorway/Hway on Regular/Premium.

My question is

Which figure should I pick?

The car is run on 95 RON unleaded here, but the manual seems to state its mapped for anything above 91 RON

This is all so I just know the correct figure to put in the garage
information:cool:

Anyway, now back to some more :turtle:

My personal opinion is that each car in the EM garage should use the FE numbers for where and when it was made/bought. This means that new cars bought in the US should use the new EPA, while older cars should use the standard from a few years back, cars bought in Europe should use the European standard, etc.

Of course, this means that models offered on both sides of the pond might have totally different numbers. I doubt that a car made for the European market would get the same results in an EPA test as its American counterpart, and vice versa. Even if the engines are the same size, each will be tuned to pass different emissions regulations on different fuel, each car may be fine-tuned for a different FE testing cycle, and each may have different trim/options.

i whole heartedly agree:)

However, the garage only has a field for US mpg..

I try to give my figures in imperial and US-i would do l/100km, but i dont know where to start!

is it possible for the garage to show different mpg fifured?

According to my saab manual, it should do 31.4 mpg uk combined

You could always take the figures from the UK test and convert them to US mpg. Google calc is handy for that kind of stuff.

I just entered my European numbers (city/highway/mixed) as mpg(US) using any l/100km to mpg calculator.

There has been talk (see US switching to metric system?, post #49) about the forum automatically converting units, but it still seems to be low on the priority list.

yeah thats similar to what i did for the avensis..cheers for the info though!

Gasoline note:

The US measures Octane in "AKI" (anti-knock index), or explicitly "(R+M)/2". AKI is the average of the RON (Research Octane Number) and MON (Motor Octane Number, a different test) octane ratings. The MON tends to be 8-10 "points" lower than RON for the same batch of fuel, so the US pump rating will be 4-5 points lower than the RON rating.

Your 91 RON is ~87 AKI, which is regular-grade fuel in most areas of the US.
Your 94 RON is ~89-90 AKI, which is mid-grade fuel in many areas of the US.
Premium fuel would be roughly 96-98 RON.

-soD

320touring -

Definitely a good question. I think that the majority use the new EPA numbers because it makes it easier to compare the "old EPA" cars to the "new EPA" cars. It also makes it more relevant when you have a conversation with someone that is considering a new car versus getting bogged down in old-epa versus new-epa discussions.

I prefer the old-epa figures because they are harder to beat, but I use the new-epa in my Garage. This way my MPG signature at the bottom of this post is comparable to other people's cars.

However, it is up to you.

CarloSW2

I use the new EPA figures for mine as well. Both are lower than I can get on the highway, but the old one was pretty close, or a hair high around town. The new one is low around town. Old was 13/17, new is 11/16. I typically get 12.5 / 19-21.

SoD- thanks for the info on the difference on RON ratings..

I'll take the 95 as top end of Mid then.

So we reckon the new EPA figures are a plan..

Ok, but which rating should I compare it to? its not driven exclusively in town, or exclusively on the Motorways...

The european tests (NEDC) are more forgiving than the new EPA test, and roughly comparable to the old EPA test. If we want equal comparisons, we should use the epa for new cars, the revised epa for old cars like mine, and a ~15% lowered adjustment for the euro ratings to roughly match the new epa.


2010 Prius (I converted the L/100km numbers into US mpg):
EPA: 51 city / 48 hwy / 50 combined
NEDC: 59 city / 62 hwy / 59 combined
EPA is 85% of NEDC.

2007 Prius (that has both old and new ratings):
Old EPA: 60 city / 51 hwy / 55 comb
New EPA: 48 city / 45 hwy / 46 comb
New EPA is 84% of old EPA.

VCAcarfueldata.org.uk - Search Results - Further Information
Model 1 Vehicle Characteristics
http://www.fueleconomy.gov/feg/compx...Field=Findacar

'Lowered adjustment' in this case means mpg, not l/100km, right? So lowering mpg by 15% = raising l/100km by 15%?

Maybe the garage could have an option that automatically calculates standard numbers depending on what type was entered? (This should go to the bottom of the to-do list, next to unit conversion.)

More forgiving to the car manufacturers then, or in easier words: less realistic ?

I'd already be hypermiling :)


Thanks for calculating the differences.

Interesting stuff!

I reckon I'll work off the 31.7 MPG UK listed in the manual, and take the New Highway EPA as my baseline for this forum

Of course, that's correct. I apologize for overlooking that.

I found the old epa tests to be pretty accurate for a reasonable driver - eg my wife. She's not a hypermiler, but she does realize there's a connection between the gas pedal and the gas pump.

Since, as you noticed, the old EPA is about the same as the NEDC, then NEDC should also be good for the average driver. My opinion is that it's pretty hard to stay within the NEDC numbers. I could barely beat them before I started aeromodding and got serious with hypermiling. Before then I was a relatively slow (only 10-20km over the speed limit, which is very slow here) self-educated ecodriver. I think that Euromodder will agree about how hard it is to beat NEDC figures. Everyone at the my local car forum has worse milage (?kilometerage?) than NECD, the few that have tried to do better gave up without extraordinary results.

Maybe the difference is between American and European driving? Different traffic, different roads, different climate, etc. I guess I'd have to drive my Peugeot around the US to really see if there is a difference.

That's my opinion as well.
Reaching the claimed 5L/100 km (47mpg) has been rather hard, and improving upon that didn't come as easy as my fuel log here may make it appear to be.

I've always had decent mileage from my cars even in my wilder years.
I was already "eco-driving" (think hypermiling without coasting, P+G, or physical mods) and driving well below the posted motorway limit before joining up here and starting to use hypermiling tricks like coasting, weight reduction, ...

Like you, I've needed hypermiling techniques to go beyond the official numbers.

I wonder if the fact that both of your cars are diesel has any relevance here. Could the NEDC ratings be harder to beat with a diesel? Maybe the test is a "best-case" situation for diesels, more so than gas cars. We don't have many diesel cars here in the USA, so I can't really speak on epa-diesel ratings.

I doubt it.
Few people do better than the official FE values for their cars, regardless of wether they use diesel or petrol engines.

My family's new (to us) Hyundai Sonata is rated for 9l/100km with the EU standards, and 9.8l/100km (25MPG) with EPA. My mom generally gets around 9.5-11l/100km, and I would say that she drives kinder than most 'normal' people. With this car being my first hands on experience with the European ratings, I was rather shocked at how stupidly low the consumption numbers are.

In the old Camry, we would get about 9-9.5l/100km, with the EPA rating being the same 9.8l/100km as the Sonata. I suspect a lot of the difference is that we do quite a bit of city driving, and the Camry's manual transmission has the benefit of no torque converter, and engine braking. Now that I'm the only one driving the Camry, it's had two tanks of <7.1l/100km :D

That seems odd to me. In my limited personal experience (4 vehicles I/we have owned), all it takes to match or beat the old epa rating is not driving like an idiot.

Example: my civic, rated 38 mpg highway (old epa). If I set the cruise control at 65 mph (105 km/h), it'll do 42-44 mpg. Using AC might bring it down to 40, which is still better than the rating.

That won't be sufficient to match the European rated fuel consumption.

Before joining ecomodder.com, I only managed to stay below the official rating twice in 181 fuelings.
Yet I was already driving 10-15 kph below the speed limit on motorways (120 kph posted); doing the limit elsewhere (mostly 70 kph / 43 mph) doing a lot of DFCO-braking; using LRR tyres; keeping fuel records; eco-parking; ...
It just wasn't enough to beat the official numbers :o

i've managed 36.2 uk mpg in the saab, despite a fuel leak:-(

I reckon i could do 40uk mpg if it didnt leak out about a gallon from the filler neck..

Certainly it aint easy-i'm hypermiling my butt off here:-)

There's clearly something not connecting here.

Hmmm... maybe the Prius is the odd one out.

2009 Honda Civic manual 1.8L iVTEC
US new epa: 26 city / 34 hwy / 29 combined
US old epa: 30 city / 38 hwy / 33 combined
NEDC: 27 city / 43 hwy / 35 combined

It looks like the NEDC rates the cars better on the highway. I can see how that would be tough to match or beat.

city NEDC -> New EPA = multiply mpg by 0.96 (civic) or 0.86 (prius)
hwy NEDC -> New epa = multiply mpg by 0.79 (civic) or 0.77 (prius)

I think I'm thoroughly confused. :p Basically, there isn't an easy translation between the ratings, because different cars perform differently on the various tests.