Consumer Reports MPG Result For 2013 Fusion & C-Max Hybrids!

Just a couple of data points:

• 19 hp = 25.5 kW
• 15 hp = 20 kW

I can't rule out a non-linear, transaxle efficiency curve as postulated by a U of Georgia paper. But this is not a trivial thing to measure.

The roll-down protocol is pretty basic and calibration is pretty much based upon a clock, level surface, no wind, and accurate speed record. By running bi-directional tests, it is hard to screw up the metrics.

I may go back and take another look at transaxle efficiency but it may take a little planning. I also want to review the Dept. of Energy papers and see if anything new has been published.

As for on or off topic, we'll have to agree to disagree. Sure on one level a CMAX owner and former Prius owner came to report he was not getting the EPA 47 MPG. His controlled, mph vs MPG and the 18 CMAX owners reporting an average of 39 MPG at Fuel Economy strongly suggests something is wrong with either the EPA rating, his vehicle, or the data Ford submitted to the EPA. But there is a Prius and wider impact from EPA ratings.

In September 2008, my NHW11 EPA rating changed from 51 MPG to 41 MPG ... magically in one night. A year ago last Spring, a Toyota dealer sponsored a rally and was embarressed when the technical crew awarded the top prizes to non-Toyota vehicles and drivers based upon their performance RELATIVE TO THE EPA RATING OF THEIR VEHICLES. And this Spring, there was no repeat rally. Then there are the fines Hyundai is facing. EPA vehicle ratings have effects that range from "braggin' rights" to paying $30,000 dollar decisions.

I'm an engineer with an insatiable curiosity about the natural world. Show me a problem that piques my interest and I'll drop just about everything to run it to ground. The Second Law of Thermodynamics has been on my list since undergraduate engineering and the EPA ratings are just a derivative. Hopefully my efforts have been enlightening and entertaining.

Bob Wilson

 

Just to correct to make sure we are reading the charts correctly
1 hp = 0.745699872 kilowatts


19 hp = 14.1 kw
15 hp = 11.2 kw

When looking at the chart we need to add power for transmission losses, and accessories.

They were just guesses based on what is modeled here.

I think some members of this forum were going to shoot me for saying that toyota too sometimes makes changes to do well on the test

As to the c-max meeting highway ratings, one thing EPA does not do is look at SOC of the battery, so they have talked about possible errors in the test based on using un counted battery power. Simply the fact that cdA is higher in the c-max than the fusion, indicates to me they should not get the same epa highway figure.

They have. By off topic, I think it deserves a diferent thread.

 

Opps . . . I agree.

carpe dieum (sp?)

Bob Wilson

 

I just did a head to head comparison between my 2010 Fusion Hybrid, which gets EPA for the most part, and the 2013 Fusion Hybrid, which gets FAR below EPA.

Test was an 11.5 mile drive each way from my house the a gas station in WI. Roads are partial snow packed, temp is 26* F. speed limit 55 for the majority of the trip, 30-35 for short sections for a total of 1 mile or less.

The tires on the 2013 are at 34 PSI, the ones on the 2010, unknown, haven't checked since the weather got cold, should do that when I get a chance.

Each car was warmed up to an extent as they were each driven prior to the test and rested for about an hour each. Trip settings were all zeroed out along with lifetime MPG readings. Left the house on EV in both, with the HVAC turned off, radio off, only lights were on and heated drivers seat. Heat was turn on about 1.5 miles into the trip, both at the same point, and floor/defrost setting on low speed. Acceleration was gingerly done in both cars, speeds were also pretty much maintained identical on each section of road with a variance of +/- 2 MPH. When I arrived at the gas station I shut each car off, and recorded the trip readouts, then filled the tank, and then updated Fuelly,com, Fuel log and fueleconomy.gov.

Return trip I drove both cars the same as I normally drive the 2010 Fusion, getting up to speed quickly, but keeping RPM to 2500 or less until I reach my set speed, in this case I drove up to 60 MPH. The return trip is also slightly downhill for a few mils, which shows in the return trip MPG.

Results are about what I figured they would be considering the Michelins do not like snow or rain, and usually drop 2-3 MPG in both. The Goodyears however, haven't shown much difference, and when I was on dry pavement, doing 60 MPH, when I lift my foot on the 2010 a bit, it stays at speed and the instant goes up over 40 and touches or passes 50 a bit before I need to apply gas to get back to speed when it slows a bit, the 2013, when I try to get it into EV at speed, it slows down quickly, and the instant never goes over 40.

End results

2013
Trip up 33.7 MPG
Return trip 34.9 MPG

2010
Trip up 33.5 MPG
Return trip 36.4 MPG

Not a very scientific test, and also not an apples to apples test, but it is a test against a known good car with a record. It's about as close as I can get considering I dont have anyone nearby with an exact 2013 Hybrid to test against.

The 2010 has the exact same tires that come stock on the 2013.

 

I never had much interest in the Fusion because it is a sedan. I sat in one but had no interest in a test drive. I did take a CMAX for a test drive even though it offered no significant advantage for my wife's wheel chair over our 2010 Prius.

The EPA spreadsheet is available and you are welcome to lookup the roll-down characteristics. As for Fusion performance, we have one engineer who bought one a year or so ago but he doesn't talk much about the mileage. I never really asked beyond giving an opportunity to 'talk technical' and he doesn't seem interested.

I appreciate your problem but without a test article, all I have access to are the EPA data and two Prius, 2003 and 2010. I've had high hopes that Ford would offer a competitive system and their EPA window numbers look good but the Fuel Economy user data doesn't:

	Column 1
0	[th]model yr[th]composite[th]user(vehicles)[tr][td]Fusion 2011[td]39[td]37.9(9)[tr][td]Fusion 2013[td]47[td]41.1(20)

Source: Fuel Economy

GOOD LUCK!
Bob Wilson

 

You know I would be happy getting 41 on the 2013, I am quite pleased with the 38 or so my 2010 is giving me. 34 is a far cry from 41 though.



Oh, since I post my numbers on that site, and so far show the most fills, that 41 may be dropping.

 

This is not correct. the current standard is based on SAE J1711 – Recommended Practice for Measuring the Exhaust Emissions and Fuel Economy of Hybrid Electric Vehicles, including Plug-in Hybrid

This specifies continuos monitoring of SOC and defines when the CD and CS segments are based on that. (Note this is true for hybrids as well).
Battery SOC is a requires standard PID on HEV and PHEV's because of that -- so anyone can monitor it.

But they do believe the car's reported SOC, so if its misreporting the SOC that could cause a problem.

There are efforts underway at both NREL and ANL to revise J1711 to better match real-world driving for PHEVs.

 

I was referring to the hybrid vehicles not the energis when I wrote that. The 5 tests are the same for hybrids and ICE vehicles AFAIK. I read from the epa that they do not monitor SOC on hybrid vehicles as a possible error on the test. That was a while back, but I have not seen mention of recent changes in the tests in the latest ford controversy Do you have information that they have changed this practice, and how they adjust mpg for changes in SOC in hybrid cars?

I really don't understand how they test plug in hybrid vehicles and adjust. At least in 2011 it appeared they used the 2 tests instead of 5 and adjusted.

 

The spec for "Charge sustaining" test (for both HEV and PHEV) require the SOC at beginning == SOC at end (within 1%). There is a procedure for correction if SOC for differences up to 5%.. and maybe that correction is what was in error (it depends on measuring a bunch of stuf).
If they just believe the Manufacture/vehicle Voltage reports, and they charging voltages are not constant, they could have greater errors in the estimated corrections. (And I can see how one could "game" that within the in rules).

There is a decent discussion in this thesis
http://scholar.lib.vt.edu/theses/available/etd-11092011-115101/unrestricted/Meyer_MJ_T_2011.pdf

PHEVs are currently using the 2-cycle test because they must run each cycle multiple times in CD (to depelte the battery), then have a soaking period, then run the cycles again in CS mode.. more soaking.. more runs in CS. Its a lot more testing than regular cars so for now they allowed the 2-cycle. Also last I heard, ANL/NREL are still working on enough statical data for the corrections of PHEVs on the 5-cycle tests.


BTW, my last post was wrong.. the SOC reported in OBD message is intended for emissions testing (which states want to be able to replicate) not fuel economy testing. J1711 specifies particular measurements for that.

 

Excellent link, that happens to show to what extent cold winter driving is under estimated.
As an aside, I wondered if the cold part of the test allows concurrent cabin heating.

 

The "cold weather" aspects of that thesis were all simulated using Autonomie. The model ignores accessories (including cabin heat) as well as changes from cold air density or changes in rolling resistance. Pretty much its a basic model with a penalty for a cold engine.
(Also the effects of Mass and Areo were all simulations).

 

Sound familiar? Gee I wonder who else stated this,

Oh thats right, ME!

 

What is the percentage of 5 out of 21? Thats the number of reported Fusion Hybrids getting or exceeding EPA. All the rest are under, or far under it.

Cmax is even worse, only 2 out of 40 at or above 47. 16 are 40 or above, the rest are below. Looks like the Fusion is actually doing better.

 

I just checked fuelly.com for the C-Max hybrid. Of the 43 cars, 2 of them are reporting averages higher than my Volt when it operates in CS (hybrid) mode. Another 3 cars are matching my 46-47 mpg average over the same timeframe that the C-MAX has been available. All 15 of the 2013 Fusion hybrids were under 46 mpg (most under 40 mpg and highest at 44.5 mpg).

Since I joined voltstats.net in early January I've driven in hybrid mode on 757 out of 1756 miles at an average of 46.51 mpg. Based on EPA estimates, I assume the Energi may do a bit worse.

Granted, those cars may not yet be fully broken in and I drive in a mild winter climate.

 

Ford sent my service manager to fueleconomy.gov for the MPG stats. I dont know about you's but does that not seem a bit strange?

Would Toyota send their techs to that site when a customer has a fuel economy issue?

 

Well it took a little more digging than planned but I took the EPA, highway mileage numbers, the raw data, and made a distribution chart:

• Toyota submits multiple HWFE (highway fuel economy) data for their models and this chart shows all three for the Prius, Prius c, and Prius Plug-in Hybrid.
• Only the Fusion HEV FWD and Jetta Hybrid are in the same group, on the low-side, but at least in the upper mileage group.

Based upon these metrics, I don't see the CMAX being an especially effective solution. The Ford Focus HEV and Jetta hybrid are competitive but just barely. But now I can offer a suggestion on how to see if this is the case in a test drive:

Based upon my benchmark test for our 2010 Prius, 45-50 mph is the target speed that returns, 70-65 MPG:

• warm-up the test vehicle - 2-3 miles should be enough
• turn off any EV or Plug-in Power feature
• begin 5-10 miles on cruise control at 45-50 mph - this replicates the same MPG point of the ZVW30 model Prius
• reset the trip meter once at steady speed and record value at end

Now this won't do a thing for City MPG metrics. Trying to get usable City performance is the madness that Consumer Reports is mired and well beyond what is possible in a typical 'demo' drive. But highway mileage can, practically be tested.

Bob Wilson

 

Ford is now facing lawsuit for overstating MPG as owners having great difficulty getting anywhere near the official figure, source:

Fuel Economy Class Action Against Ford C-MAX Hybrid

Galaxy Nexus ? 2

 

Ford's PR isn't handling this very well. I bet there'll be a few strategic employee changes at Ford.