chimmike

it wasn't a tow test. it was a payload test.

"5.7.2. Increase pay load testing for transmission mapping Further testing of the F-150 was done with increased road load emulation to simulate a higher payload. The chassis dynamometer road load coefficients were kept constant but the test weight was increased to 10,000 lb for the high payload testing. The increased payload test was performed for a UDDS drive cycle and included three different cases: (1) standard vehicle weight of 5250 lb with transmission in normal shift mode, (2) 10,000 lb vehicle weight with transmission in normal shift mode, and (3) 10,000 lb vehicle weight with transmission in tow mode. Note that the vehicle owner’s manual states that if equipped, the vehicle should be placed into Tow/Haul mode as described below:"

page 59.

P 60:

"The fuel economy results and transmission gear histogram for the three test cases are shown in Figure 45. The additional payload of 4,750 lb reduced the fuel economy by 29 percent in normal shift mode and by 36 percent in the Tow/Haul mode....."

acdii

Road Load, as on the rollers, not on the chassis. The only thing they can't account for is wind resistance on frontal area. In essence they simulate towing a trailer by increasing the road load on the rollers. I highly doubt they dropped 4750 pounds in the bed of the truck. The trailers weight my not be in the bed of the truck, but this would be the closest they could get to simulate towing a trailer. That plus the fact the F150 is in the under 8500 pound GVWR category.

SHO4CY

A couple items to note:
1. in the 2017 model year the 5.0 did not have the 10 speed transmission even though the report says it did.
2. Eco mode was not available on 2017 model year, just normal, sport, and tow/haul (in response to @flynavy812 )
3. I see why my rpm's are a little goofy when accelerating in 3rd gear as the transmission slip varies quite a bit (by design). I notice that my revs will be higher initially then lower slightly before raising again while accelerating in 3rd gear.

B00Ndocker

Thank you for finding and posting this! At halfway through this report, I can't tell you how thrilled I am to be reading empirical, factual results with full explanation of the testing methods used to achieve them and some similar vehicle comparisons as a bonus. Furthermore - presented without a lick of bias or emotion. Full disclosure - I'm a career systems (software not mechanical) test engineer, so you'll excuse me if I geek out over this.

After the first read through, if I'm motivated and there is interest, I may reproduce some sections with Clif Notes covering some of the most oft-debated and misunderstood subjects on this forum - like transmission behavior, auto stop-start feature and whatever else I find interesting in the second half of the report. I'm not interested in debating the merits of design. For me to understand how something works affords the most opportunity to make the best of it.

Getting reliable information from an internet forum is a lot like gold prospecting - lots of sifting for a few nuggets. This report is a real gem for those of us who own a 2nd generation 3.5 Ecoboost / 10-speed and are interested in an in-depth dissertation on how and to some extent why our power train performs. I visit the f150forum frequently because I want to learn more about my vehicle - not just the hard engineering stuff either. So this is like forum prospecting payday! Thanks again.

riptide88

Thats very surprising to me too because i wouldve thought for sure it was a major killer to mpg. Not complaining at all and like you im using sport mode more lol

w00t692

The power the 3.5 makes on 87 octane is about a 25% drivetrain loss. That doesn't really line up with modern transmission efficiency. I'd expect something sub 20%. On 93 on average they make within 13% of rated power. On 91 i'd be willing to bet money they make right around a 15-18% loss which puts it right in line with modern drivetrain efficiency.

Looks like a raptor makes right around 370-380, that's 18-20% drivetrain loss vs rated power.

sdg516

Thanks, amascio, for posting this report!

A few of the things that stood out to me:

• Section 5.2.7: "The majority of the engine operation is below 2,000 rpm for the UDDS the Highway cycles. Even on the more aggressive US06 cycle, the median engine speeds are around
  1,500 rpm that is comparatively low. The maximum speed on the US06 cycle is below 3,500
  rpm." Well, that helps explain my poor fuel economy!
• Section 5.2.9: Table 15 is pretty cool, in showing the benefits of start stop function. Not a surprise, that in a New York City Cycle, fuel ecomony can improve by nearly 11%. But for the US06 test (which is more what most of us drive) the savings are 1.9% I have an autostop eliminator, so my savings are zero
• Section 5.3.1: "The best fuel economy of almost 45 mpg is achieved at 30 mph...The peak efficiency of the vehicle is 29 percent at 80 mph." So, should I try driving at a steady-state 30 mph and see if my 36 gallon tank takes me 1,600 miles? I do like knowing the peak efficiency is at 80 mph. Don't mistake peak efficiency for best mpg, peak efficiency is where the fuel going in maximizes return on investment from the engine (power to the road)
• Section 5.3.3: "In this case the powertrain required about a second after 100 percent application of the accelerator pedal to build up boost and downshift from 10th gear to fourth gear. Similar to the maximum acceleration test, the injection system switches to 90 percent DI initially and settles at 60 percent DI and 40 percent PFI once the intake air pressure is fully built up by the turbocharger." Pretty impressive, to take one second for boost to come online and transmission to downshift from 10 to 4.
• Section 5.4.4.1: "In the low load area represented by accelerator pedal position below 15 percent the transmission shifts as soon as possible. In the medium load area represented by accelerator pedal positions between 15 percent to 70 percent the transmission starts to hold the gears longer to enable the engine to make enough power for the driver demand. In the high load areas represented by accelerator pedal positions above 70 percent, the transmission waits to shift the engine until the engine has reached its maximum allowable operating speed" Again, helps explain my poor fuel economy
• Section 5.4.4.2: The [torque converter] is mostly open with a limited number of slipping points for 1st through 3rd gear. This is used for vehicle launch and idling. For 4th through 10th gear, the TCC is only locked or slipping.
• Section 5.5: Not a surprise, hot and cold weather affects fuel economy (but for most driving conditions, not too bad, less than 3%)
• Section 5.6: I loved this section! Basically, running premium doesn't do much for fuel economy, except the US06 cycle (which most of us probably drive), showing a 1 mpg improvement (Table 23). Tables 24 and 25 are awesome, showing that premium does improve acceleration. 0.7 second improvement to 80 mph, and 0.7 improvement passing 55-80 mph. I use premium in my truck, as I want the engine to operate at its best. It does make a (admittedly minor) difference. I'll take it!
• Section 5.7.1: "The Sport and Tow/Haul modes reduce the fuel economy by 1 percent and 2 percent, respectively. Even though the fuel economy difference between the different modes is minimal, the gear usage by the transmission varies significantly between the modes." I didn't realize sport mode has so little affect on fuel economy (I believe it improves driveability in some situations).
• Section 5.7.3: I didn't realize how active the active grill shutters really are. They are opening and closing many times throughout a daily drive.
• All Appendices: Hard to argue with hard data. Well done! Pretty cool to see peer review feedback in Appendix E.

Kudos, Ford. Just reinforces what an impressive powertrain the 3.5 EB/10-speed is. I would extend this admiration to several of the EB motor/drivetrains (having previously owned the stellar 2.7)

h2ouup2

This is very interesting. Thanks for the report.

blkZ28spt

Sold!

MNgopher

One quibble with the summary above- the affects of temperature were actually much greater than 3% in terms of fuel economy. The 3% difference is the powertrain efficiency, which is different than the fuel economy.

The 20 degree F temp testing was actually 22% lower fuel economy on the first cold cycle, and 8% lower on the second. (See page 51, under Figure 36). The basic point being the longer the unit operated in the cold temps, the closer to baseline (72F temps) the effiicency moved (mainly due to the heating all the lubricants through the preceeding cycles).

For some of us, 20F is a normal regular temperature for much of the year (see my location for questions). And if short tripped (as many of us do), matches what many of us see in the winter...