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Discussion Starter · #1 ·
All,

So I'd gone to the dealer as I could tell I was having an issue with my IWE/vacuum system. I didn't have both my phones so I couldn't book an appointment and ended up having to drive the truck over last weekend. Turns out that was the straw that broke the camels back. I could hear things going south just before I got home, and was just able to make it up a snowy road in 2wd as the 4wd system wouldn't function. So I'm betting the front hubs are now trashed inside.

My question is... as the system failed at 40K miles I really don't have a lot of confidence in it, and if it fails when I need 4wd to get/leave home I'm screwed. Any wisdom on the issue of either replacing the broken parts of the system or installing Dorman or RCV Performance IWE delete kits? I'd rather not impact mileage, but I put my preference on getting home. Also, if you have experience with either IWE delete, did you notice additional noise/vibration in the truck. (Pretty partial to the comfy and quiet cab.)

Thank you.

Dan
2019 F150 PS - Stock, but maybe not much longer
 

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@Built2Order - Let me be the first to welcome you here to the forums!

Can you provide a few more details before I attempt to answer your questions?
  • Purchased new or used?
    • If purchased new, what was purchase date?
  • Trim level?
Thanks in advance.
 

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@Built2Order - was wondering if that is where your handle came from!

I have factory-ordered my last two F150 Platinums, as I figure if I am going to drop north of $60K for a vehicle, then I am going to get what I want...

In terms of your IWEs here some of my thoughts:
  • XLT trim gets you the "simpler" 4WD wheel hub setup:
    • Lariat and above trim levels come with AWD and the "always spinning" front 4WD axles
      • 2015 model years and up have an issue with needle bearing (in the wheel hub assembly that is the receiver for the this spinning shaft) spins dry of grease creating noise on deceleration
      • AWD option and the "always spinning" front 4WD axles is what accounts for contributes to the 3-5 MPG decrease in model MPG due to parasitic loss
    • Your XLT still has IWEs to engage 4WD
      • Some Ford techs hate dealing with Ford's IWE design on the F150s
  • In terms of your truck warranties
    • While you are easily under the 3 years of your 3yr/36K Bumper-to-Bumper warranty, you are over the 36K (disregard green box around PowerStroke Diesel 5yr/100K warranty)
      Font Parallel Number Rectangle Slope
    • However the IWEs are considered part of Ford's F150 5yr/60K Powertrain warranty
      Font Rectangle Number Screenshot Handwriting
Personally I think I'd force Ford to replace your IWEs under your 5yr/60K Powertrain Warranty on their dime and save up your $$$ to be ready for the same questions/decision you are asking now in another 40K miles...
 

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Discussion Starter · #5 ·
@jmperlik Excellent. Thank you for the info. I'm surprised there's that much of a difference in MPG with the AWD option in the higher level trucks, and I guess that might approximate the penalty I'd pay if I went with either IWE delete system. I worry that I'd also pay a penalty in noise. With 4WD engaged (even though it isn't really working as 4WD due to the damage) it's quieter than in 2WD. In 2WD it'd run silent for a bit, then it sounded like all of a sudden my truck was running big swamper style lugs. As that noise used to be fairly short lived I'd always (mistakenly) assumed it was a noise associated with a DPF burn or something. Now that noise no longer goes away. Not quite sure I'd be happy living with that and a big hit to MPG.

On a side note, how to you like your Titan tank? I'm considering one for my truck as I just love the range capability of high MPG and a large fuel tank.

And thank you for your answers above.
 

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On a side note, how to you like your Titan tank? I'm considering one for my truck as I just love the range capability of high MPG and a large fuel tank.
I like the extra range/distance between fill-ups of the 36 gallon XXL tank on my F150 Platinum. FORScan provides the ability to change tank size so that the DTE (Distance To Empty) is accurate.
I probably don't take enough long trips to justify the cost, but this was something I just wanted.
No problems to date with the tank = I am happy with the upgrade!

And thank you for your answers above.
You're welcome!

Please feedback here in this thread what you ended up doing to resolve this issue.
 

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Jmperlik: I’d be very surprised if the Lariat+ AWD/4WD lost 3-5 MPG. My 2021 Lariat (with a bunch of additional options) gets better than 30 MPG if I set the cruise control at 70 MPH on mostly level highway.

Instead, I think the difference in “EPA rated” MPG is due to higher weights of the more highly optioned Lariat+ models. The EPA ratings are not based on actual road testing, but on a specified dyno test which is adjusted for vehicle weight and type. This is why real world mileage is often substantially different than the EPA ratings. The additional rotating parts in the front axle may only subtract 1MPG, if that.
 

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@PeteK - agreed that weight is also contributing to the the drop in MPG between the XL/XLT and Lariat/above models.

Believe me I scoured the Ford marketing material when purchasing my 2015 Platinum (V8 gas) and 2018 Platinum (V6 Diesel) and could never understand the large MPG disparity between the XL/XLT vs Lariat/above models. Yes, 4WD (heavier hubs w/IWE + transfer case + front differential) and all of the creature comforts I like (Panoramic sunroof, massaging seats, etc) definitely increase the curb weight as you go up in trim levels, but that alone could not account for all of the MPG delta.

I don't remember exactly where I read about the "always spinning shafts" information, but you can understand how the shafts always spinning is a parasitic loss that is contributing to the MPG delta = HP being used to keep'em spinning. I will be more careful in the future stating that AWD is a contributing factor to the decrease in MPG. I only raise this as an interesting factoid that many owners probably never knew about when purchasing.
 

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Discussion Starter · #9 ·
So the truck went to the dealership for the eval & fix, and... they covered it under warranty. It was the IWE. Their verbage at the bottom of the slip: "Found 4x4 function is intermittent. Found left front hub is always engaged even when mode select switch is in 2x4. Verified IWE system all holds vacuum and no leaks present. Verified switch and solenoid applying vacuum correctly. Removed and inspected LF IWE. Found IWE has broken. Installed new IWE."

So the decision of whether or not to remove the IWE system will wait for another day.

Cheers!
 

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@jmperlik I guess I failed to communicate clearly. The EPA runs the trucks on a chassis dyno to get those mileage ratings as well as check emissions and other requirements. Since the vehicle is strapped on a dyno, instead of a real road test, they have to apply correction factors to account for air drag, rolling resistance, weight, and some other factors. I forget all the details, but the important factor is that different corrections are applied for different weight and configuration classes. To use a poor analogy, its kinda like bumping into a different tax bracket when you increase your income.

Out here in the real world, you don’t apply correction factors, you see what it does on real roads. In fact, a few hundred more pounds of weight makes virtually no difference in fuel consumption, on relatively level highways because increasing the weight by, say, 10% increases rolling resistamce only by a small fraction of that. The biggest factor in fuel consumption at highway speed is air drag (and that increases by velocity squared, which is why higher speeds reduce fuel mileage drastically). An XL has virtually no difference in drag compared to a
Platinum model—they are the same cross-section and the same “brick” profile (if anything, the 4-door models are a tiny bit more aerodynamic than the single cab, but not enough to notice on your fuel gauge).

So, the way the EPA artificially calculates fuel mileage is inaccurate, but consistent enough to compare the expected mileage of different vehicles. As the sticker euphemistically states, your “actual results will vary.”

Re the additional rotating parts in the Lariat+ models, I plan to ask the techs about that when I take my truck in for its first service next month. I doubt that even if there are additional rotating parts, that the parasitic losses cause a loss of around 2MPG. It doesn’t take much power to spin parts in roller bearings that aren’t connected to anything.

In the meantime, I’m watching for someone who owns an XL or XLT to discuss their fuel mileage, so we can compare. I know from carefully measuring the actual fuel used that my Lariat+ with additional options gets in the range of 30+ MPG at constant 70 MPH on relatively flat I-5 between Portland and Seattle. That’s 3+MPG better than the EPA rating. Is anyone with a XL/XLT reporting 33+MPG at constant 70MPH? I don’t think so.
 

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@PeteK - so riddle me this: Ford has been systematically pulling every trick-out-their-hat to improve their fleet MPG, as CAFE requirements require them to improve MPG across all of their vehicles.

The following is a list of improvements Ford made the F150 platform over the past few years in order to raise the F150 2WD XL/XLT models to the mythical 30 MPG they announced in 2018 w/3.0L V6 "Lion" PowerStroke Diesel engine:
  • All aluminum body panels (2015)
  • 10 speed (10R80) transmission (2017)
  • Auto Start-Stop (2017)
  • Special Low HTHS viscosity F150 Diesel engine oil (2018)
The last two (2) items have been discussed in other threads and maybe add 0.25 to 0.50 MPG to the overall total.

If Ford is fighting for every 0.1 MPG that they can add, how do you explain these ratings:
  • 30 MPG => 2018 (2WD) F150 XL/XLT trim w/V6 3.0L PowerStroke Diesel Highway rating
  • 25 MPG => 2018 (4WD) F150 Platinum trim w/V6 3.0L PowerStroke Diesel Highway rating
Besides weight and rear differential ratio, these are the same trucks with same aerodynamic profile as you state.

Where do the 5 MPG go between trim levels for same model year w/same engine? Are you saying Ford just allowed the EPA to derate the Lariat and above trim levels, when they have been scraping for every MPG they can find to get the F150 3.0L V6 PSD to the mythical 30 MPG highway rating for a pickup truck? Several members here compared 2WD vs 4WD for Dodge and Chevy 1/2 tons and found only a 2 MPG difference between trim levels and no one could explain the 3-5 MPG drop on the higher Ford F150 trim levels.

You are postulating that I can't be right, yet you fail to explain what the cause(s) of this MPG difference could be.
 

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@jmperlik Good questions. And I'll add another one: Why is the EPA Highway rating for your Platinum 25 MPG, and for my Lariat+ 27MPG? I don't think I "fail to explain" the anomalies in the EPA ratings--I'm as puzzled as you are why those differences are so large. I do know that my ACTUAL MPG beats the EPA highway rating by 3 MPG (30 vs. 27). Is anyone with an XL reporting 33+ MPG?

I looked into how the CAFE calculation works several years ago, and I came away with the understanding that it's really complicated, somewhat arbitrary, driven by lots of lobbying by the car manufacturers and the UAW, green groups, etc. It's a rabbit's warren of rules and exceptions and adjustments that only the lawyers and lobbyists who do this for a living understand, if even they can understand it. And then they change the rules again. For awhile, there were credits for "alternative fuels" including biodiesel, but those were modified or repealed recently. Here's another factor: "footprint." The larger the vehicle footprint, the lower its MPG rating can be without adversely affecting the target corporate average. That's the main reason that Explorers have become almost as big as Expeditions.

I'll guess that Diesel engines don't help the CAFE calculation much, otherwise, why would Ford have dropped the diesel option for the F150? And if higher mileage cars helped meet CAFE requirements, why did Ford decide to get out of the small sedan market? You'd have to get to someone in Ford's marketing department to get answers to those questions.

Anyway, there's a long article in Wikipedia about CAFE, and even that is greatly simplified.
Corporate_average_fuel_economy.
 

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Here's one of the articles I remember reading which explains the 5 MPG highway difference between the 2WD and 4WD: 2018 Ford F-150 Power Stroke first drive: diesel, the not-so-efficient way

The EPA test figures will get your attention... : 22 mpg city, 30 mpg highway, 25 mpg combined with rear-wheel drive, but just 20/25/22 mpg for the four-wheel-drive variants Ford expects to be more popular.

Ford explained that hefty highway fuel-economy disparity by blaming it on a few factors:

For one, the automatic four-wheel-drive system’s transfer case is both heavy and the root cause of some parasitic driveline loss. Additionally, rear-drive trucks are fitted with smaller tires—street-oriented 245/70-17 instead of all-terrain 265/70-17 rubber.

The more complicated explanation lies in the way Ford approaches the EPA test by certifying what it expects to be the most popular body styles and trim levels for each set of drive wheels.

Ford expects four-wheel-drive models to be mostly dressier Lariat, King Ranch, and Limited trims. For the rear-drive version, Ford says it anticipates a shift in favor of fleet trims not decked out with niceties like leather seats, oversized wheels, panoramic moonroofs, and thumpin’ stereos.

Ford anticipates that rear-drive diesels will skew toward fleets, so it won’t offer the XL and XLT trims with the engine to retail buyers. Fleets can order them and Ford will undoubtedly offer plenty of charts to show how 30 mpg will eventually offset a premium as much as $4,000 higher than standard gas engines depending on the trim level.
AWD drive "always spinning axles" means a front differential + 2nd driveshaft + transfer case that is always spinning also to keep those "always spinning axles" spinning = this is not free. Perhaps the convenience of the Ford's ESOTF 4WD system and always spinning AWD is an expensive design implementation for the maybe 1/2 dozen times/year that I actually switch into 4WD (like during the snow/ice we got in NY state last night/this morning)

In terms of Ford's corporate strategy for exiting the 1/2 ton diesel market and most of their car business, you'll have to talk to their board. I would guess it is a combination of EV allure and going with the vehicle line-up that generates them the most profit-per-vehicle. It was very easy to see their profit margins via X-Plan pricing when I contemplated buying a 2014 Ford Focus for my daughter (ended up leasing) vs my 2015 F150 Platinum.

Regardless, all automakers are looking for any trick-in-the-book to improve MPG to raise their corporate CAFE goals.
 

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A data point regarding EPA rated fuel mileage for our 3.0's: My 2019 XLT 4wd has a 21 city / 28 highway / 24 combined EPA fuel mileage per the Monroney window sticker.
My truck has these settings for the transfer case: 2H, 4H, 4L. It does not have the 4A setting that's standard on higher trim models.
 

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@STIAJW - thanks for adding your data point, as I think it helps breaks things down further.

Your 4WD XLT (w/o AWD) shows the 2 MPG delta from 30 MPG 2WD XL/XLT models:
  • Siimilar to 2MPG delta between 2WD and 4WD for Dodge & GM
    • I have never looked at the 4WD systems on either Dodge or GM 1/2-tons
  • Also shows that Ford's AWD implementation is not free, as Lariat & above models are < 28 MPG
    • Same truck/same aerodynamic profile = only difference is 4WD vs AWD
    • I stand by my assertion that Ford's AWD "parasitic driveline loss" is a contributing factor
The Monroney sticker 20/25/22 EPA ratings for the 2018 Lariat & above trim levels are well-documented (on at least a dozen websites) and well-scrutinized (see article link above) as everyone was looking at the EPA ratings for the 2018 (first) model year for the F150 PowerStroke Diesel.

@PeteK - what are the EPA ratings for your 2021 Lariat? 21/27/24? If so, I can only guess they made improvements over the 2018-2020 models in their AWD design to raise the highway MPG rating from 25 MPG to 27 MPG?
 
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Regarding real-world fuel mileage over ~22,000 miles, my truck averages ~26 mpg during the spring, summer, and fall. During the winter, it averages ~23 mpg. This is probably about 75% highway speeds of 70 to 75 mph. These are calculated mpg's. I've also tweaked the bias setting on the in-dash mpg calculation so it's tracking consistent with my calculated mpg.
On the highway at about 75 mph, headwinds decrease mileage to ~23 mpg, and tailwinds increase mileage to ~28 mpg or so. It seems I've hit headwinds more often than tailwinds on my trips.
During the winter, when the outdoor temp is ~15 F or colder, at highway speeds of ~ 70 mph, my truck will keep the transmission in 8th and then 9th gear for the first 8 miles or so, with the engine at ~2,300 rpm in 8th to ~2,000 rpm in 9th. When the engine and transmission warm up sufficiently, it finally shifts to 10th gear and drops the engine to ~1,600 rpm.
 

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QK, I'll bite, but I don't think I have enough empirical data to support either of our positions due to:
  1. I have a Titan 40 gallon XXL tank installed on my 2018 Platinum (+750 miles between fill-ups)
  2. I track MPG using Trip meter divided by (n+1) fill-up where the entire trip is highway mileage
  3. I don't do enough highway driving to calculate true highway MPG (most tanks are mixed city/highway driving mileage)
I will however highlight what I feel my "bests" are which are one-offs more than anything I would consider average:
  • My best highway mileage trip to/from Boston where I hit 30.5 MPG on return leg (200 mile trip)
    • Warm but not hot weather where I think I got a tank of higher-than-normal Cetane level
  • My last long highway trip down to Charlotte & back in 2 days last summer where I averaged:
    • 27.8 MPG on the way down (~700 miles w/zero traffic)
    • 27.2 MPG on the way back (~700 miles w/1 hour traffic delay south of DC)
  • Most other highway trips, I would guess that I am in the 25-26 MPG range
  • All of the above were at 70 MPH (set via cruise control) in Eco driving mode
Quite frankly I'm happy to see anything over 25 MPG in the Lie-o-Meter for a 5100+ lb pick-up truck, which is something I never thought I'd see in my lifetime...
 
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Thanks.

FYI, I drove across the scales at the local landfill a couple days ago. Recall that I have a 2021 Lariat A/4WD with additional options. Weight of the vehicle with 3/4 tank of fuel plus my brother and me was 5940lbs. The two of us dressed was around 420 lbs, and I had about 20 lbs of miscellaneous stuff in the back of the cab, so I figure the truck with 3/4 tank was about 5500 lbs. Diesel weighs about 7lbs/gal. so say 20 gallons of fuel. With an empty tank the truck weighs about 5360 lbs.

Your platinum might weigh a few pounds more if it has the glass roof. Mine doesn’t.
 
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