Alright...here we go.
First off, for those that don't know - see my disclaimer in the signature. Yes, I do work for Ford as a Global Core Weight Engineer in our facility in Allen Park, Michigan; but my daily job as actually very little to do with fuel economy (it's indirectly related).
Second, I myself bought a 2013 Ford Fusion Titanium Hybrid. I did so for a number of reasons, the first of which was because I poked a hole in the bottom of the oil pan of my old 2003 Chevy Cavalier (literally -- it was quite a bit bigger than the size of a U.S. quarter. I always thought that I would get a new car because I run the old one into the ground - I didn't think that I was going to be doing it quite so literally when I cut a corner a little too close and the inboard side of the curb (the grassy area) - the ground was sunken in (a la pothole, but obviously not a pothole per se) so that meant that my right wheel cut the corner, and fell into the hole, which meant that between my front left wheel and my front right wheel - I was straddling the curb = coming out of a parking lot; fell hard/far enough to poke said hole. And after fixing the car twice (under insurance) and the check engine light kept coming on - I gave up on it). I drive ~40,000 miles (~65,000 km) a year; so I needed something fuel efficient. Test drove both the Prius and the Jetta Hybrid - decided against both for different reasons (which I won't get into now). And the Fusion actually PASSED the Insurance Institute for Highway Safety (IIHS) Small Overlap Crash Test (usually referred to as the small overlap rigid barrier or SORB) test. So, for those reasons, I pay a LOT of attention to the fuel economy stuff, cuz I run the car myself; so it has no relation to the company or the fact that I work for them.
Third, it's always interesting reading the general public (who may or may not be engineers, and more specifically automotive engineers) looks at and interprets this fuel economy stuff.
Fourth, please understand that because I DO work for Ford, that I have to be VERY careful about what I put in writing. (I'm actually probably going to be drawing upon my class material and lecture notes and stuff from when I took my hybrid electric vehicles course when I was doing my undergrad (BSME, Kettering University, 2009) MOST for legal (and liability) reasons. That also means that there might be some stuff that I CAN'T answer (to put in public record).
So, with all that out of the way, if you want the pictures of my hole-in-oil pan and also the curb where I hit - message me and I'll post 'em up. Yes, I've got pictures. No, I haven't uploaded them anywhere yet; but I have nothing against sharing them.
First off - fuel economy isn't really "fuel economy". The way that fuel economy is measured, yes, the EPA defines the test schedules, but the idea that we run it and then measure how much fuel we consume (which you would think would be the easy way of measuring fuel economy) isn't what actually happens.
1a) Fuel economy is measure moreso as a "result" of emissions, and NOT the other way around. Fuel economy is actually a back-calculated value from the emissions results; which is something I don't think that a lot of people in the general public know about.
b) To ALL the people who were talking about the whole real world vs. lab world (or EPA/Ford) tests - and some of you have probably seen me say the same thing (I think?) - so many people are critical about it and the results that they produce to which I usually ask them - ok how would you come up with a test that will be able to capture 99% of how people drive in the US - ranging all the way from hard core traffic in downtown Manhattan and L.A. to the farmer in Idaho, doing 80-85 on the long, flat, straight road? From the drivers in Florida (lowest elevation) to those in Colorado (highest elevation)? To the people in Alaska (coldest temperature, with the heaters jacked up on high) to the people in Arizona (hottest temperature, with the A/C cranked up)? What would THAT test look like? And it seems like that the moment I frame the fuel economy tests like that, the person's who has complaints still complains, but also realizes that it's not as easy as they might once thought. (And since the rate of acceleration is specified, it has to (loosely) cover the grandma's style of driving to church to the lead-footed men AND women)).
And the tests cannot be cost-prohibitive, and they can't take forever. In fact, I think that if you were to add up all of the tests, two required and three supplemental; I think that the schedules combined is like less than an hour total time.
2) It's a bit of a history lesson on dynos (and I'll be honest, I have very, very little experience with them), but from what I'm told; they used to actually have to physically put weights on the dynos in order to give it the inertial resistance. I'm not sure exactly HOW that worked, but dynos aren't just dynos. The resistance on the roller is supposed to represent the resistance that the vehicle will see when it's running on the road. This is important because it leads to this concept called "equilvalent test weight" or ETW. Back in the day, they could only physically add weights in 250 lb increments, so this lead to what's called the ETW tables. That means that if your car weighs a certain amount, it's classed in/lumped in with other vehicles within that ETW weight class (hence why I said what I do is indirectly related to this). Modern, computer dynos have much greater control, but because of the history and the amount of baggage that the US legislations carries; that's how the dynos are set up. (In water brake engine dynos, modern ones control the amount of resistance (work that the engine has to do/load) by the amount of water in the water brake). I'd assume that the weights on a chassis dyno is a similar idea nowadays.
And it's more of general history lesson as well it being a lesson on the history of the EPA regs which came about since ~mid 70's.
Once you understand those pieces, understanding how Ford (and ALL automakers) do the fuel economy testing ought to be easier.
So, unfortunately, to the OP that started this thread - mehhh...the theories aren't exactly true.
The test schedule is governed by Title 40, Code of Federal Regulations, Part 86 (which, by the way, is a total of 1211 pages if you read both Volumes 19 and 20; which you can download from thomas.loc.gov; which I had to (read)). If you are REALLY bored and you have nothing else better to do (or it's your job as it was in my case) - read it. It's quite interesting actually - especially on a "fuel economy" internet board.
Per the official releases and stuff - we've done exactly what US federal law requires us to do, in the manner that the US federal law requires us to do it in. Any deviation from that would have been really, really bad.
And while I can't comment on EPA/Consumer Reports - let me put it to you this way - you don't see Consumer's Reports say much more about us (Ford) lying about the numbers.
And as I always have before (I gotta run for a meeting) - you can find an article in Car and Driver which says why the EPA tests aren't so good for predicting fuel economy in electrified vehicles (like hybrids, plug-in hybrids, and full electrics (which BTW, doesn't even use the EPA test procedure, cuz there's no emissions to be measured) ).
Edited by alpha754293, 16 September 2013 - 12:57 PM.