Let me preface by saying I didn't intend to write this much originally but it sort of just flowed out.

Got a bit of an interesting somewhat apples-to-apples comparison here. I tow a 7000lbs Grand Design 2400BH travel trailer and went from/to:

• 2020 F150 2.7L 145WB CCSB 3.73 ~5000lbs curb weight 275/65/R18 AT LT-E 53lbs tires (32.1" diameter, 629 revs/mile)
• 2024 F250 7.3L 160WB CCSB 3.73 ~7000lbs curb weight 275/70/R18 AT LT-E 52lbs tires (33.2" diameter, 609 revs/mile, 3.4% greater circumference).

At town driving speeds the Godzilla engine pulls well generally using less RPM than the 2.7 eco.
But at 65-70mph highway speeds the 2.7 eco is far superior in every way and I'm rather extremely dissappointed with this outcome. Some F150 2.7L data points:

• Lock out 10 and can tow in 9 at ~1800RPM on flat highway with power to spare
• Lock out 10 and 9 and can tow in 8 at ~2200RPM on the majority of hilly terrain on i-75 between Chatt and Knoxville TN with no downshifts in cruise control at 68mph.
• Climb the worst hills in this stretch of i-75 and needing no more than 6th gear and 3200RPM
• 68mph smooth cruising fuel economy: 10.5 mpg (using 93 octane)

Compared to my new F250

• Go to M and choose 9 and I cannot maintain 70mph on level highway, slowly bleed speed away with WOT
• 8 can maintain 70mph at level and only the slightest uphill
• Need 7,6, and even 5 to climb hills my 2.7 did in 8!
• Need 4 and 4000+ RPM to climb hills my 2.7 did in 6!
• 7.3 engine is far louder than the 2.7. 2000RPM 7.3 sounds like 2500RPM 2.7. 4000RPM 7.3 is just ridculous compared to any RPM I can make with the 2.7
• 65-70mph fuel economy: 8 mpg (using 87 octane)

I don't think anything is wrong with the new truck/engine. Currently has 2K miles on it, did not tow until 1K miles. Unladen I get 17 mpg at 65-70mph and this is generally on the high side of what 7.3L 3.73 owners report (my 2.7 gets 22mpg with 87 octane, 25mpg with my old P HT tires). I can also hold 10th gear for most hills and no worse than 8th to climb the highest grades. And as I said before my towing performance/torque is strong at lower speeds. Note that I will eventually do a 93 octane highway tow and I expect it to help a little bit but I won't know until I try. I've also towed with 87 octane on my 2.7 but that is a forced induction engine so it shows more difference. Generally it's like loosing half a gear or a couple hundred RPMs in perf. 93 in 9th gear would be matched by 87 in ~8.5th gear and so forth.

Unfortunately highway is a bit of a disaster. Cruise control + lock out 10/9 is effectively useless as every hill the truck immediately bleeds speed in 8, drops to 7 for 1 second, then double-drops to 5 in a panic to recover lost speed, finally cresting the hill holding 5 for a few seconds and then restoring to 8th. This has been horrific to my sanity and my passengers' sanity to have this process repeat over and over. For CC to work I basically need to lock out 10-7 to not be shifting on every hill and that is equally awful to me for noise and fuel economy reasons. I can mitigate by going without CC but now my mind and body is constantly engaged with locking out gears leading up to a hill and carefully modulating the gas pedal to extract as much power in the current gear without the computer deciding to drop gears for the last 2 seconds of the hill I am about to crest as I bleed speed. This is extremely tiresome to maintain over multi-hour drives. This experience lead me to trying M mode and selecting M8. I've learned to put my foot down approaching a hill to build some speed, and it will hold 8 or I will drop to 7 as I climb the hill and target bleeding speed from 75mph to 65mph. This technique appears to be the best strategy for balancing noise, shifts, and mental engagement. It is also a technique I never tried on my 2.7L because I never had to. On that platform it was just CC + lock out 10/9 and that was it. But now I have become yet another truck/trailer that can't climb a hill and hold speed. This is a tough pill to swallow after towing almost 4 years with the 2.7.

Which brings me to the conclusion of my post here. I knew going from a forced induction engine to a naturally aspirated engine meant I'd lose some performance down low. But I never expected that a 7.3L displacement engine would be so thoroughly outperformed by a 2.7L twin turbo engine, but it is. Granted the GCW of the F250 is around 15K lbs versus 13K on my F150 but that is hardly enough to explain the difference. I ran my 2.7L 53a truck right up against its GCWR and exceeded its payload limit but that thing worked flawlessly and gave much better towing and unladen fuel economy. Highest transmission temp 215, highest engine temp 210. My F250 is getting 225/210 doing easier grades (I've yet to take take the F250 up the big daddy grades in east TN like i-24 Monteage Mountain). I'm really disappointed and if I knew this I would not have switched. When I bought the F150 it was covid inventories and I didn't know about trucks. I screwed up on payload (1600lbs) and also RWD but that 2.7 was dynamite. Now I got a payload monster (3700lbs) and 4WD but I feel like I've made a very significant downgrade in engine and this despite my research. One thing I tried to do was compare dyno graphs of torque and HP. And those graphs actually show very similar values and slopes in the 2000RPM range so I thought it would be only slightly worse. But in actuality it seems like the 2.7L eco delivers much more power as a function of RPM in the 1800-3000RPM range than does the 7.3. It's really not even close. At low speed 2000RPM 7.3L godzilla can accelerate my trailer like the 2.7L eco does at 2500RPM, definitely not the case at high speed. Seems to me torque curve of the 7.3L is fine below 3000RPM but HP is strongly lacking. I wish the dyno graphs would show this.

Okay I'm done my rant. Feel free to ask any other questions you might have regarding comparison of these 2 trucks. I'll preemptively start with one more comparison that ties in to the engine and I want to share it:


I'd say engine braking on the 2.7 eco is 80% as strong as Godzilla in absolute terms and much better in general. With the 2.7 engine braking doesn't kick in until 2000RPM. Below that you coast very efficiently. At 2000 the braking kicks in and comes on fairly strong. In Tow/Haul this happens naturally by lightly pressing the brake and the computer drops the gear to get you in the 2000RPM band. Brake harder and gears drop further, eventually dropping to 2nd gear and 5000RPM on a steep downhill grade. It roars and it works damn well. Enter the 7.3. This thing seems to have parasitic engine drag coasting at any RPM. I can feel it (lightly) at 1000RPM compared to neutral and I can feel it get stronger as I approach 2000RPM. This is considerably worse as I have to feather the pedal in many places I used to just coast. It's both annoying and a fuel economy drag for sure. Also around 2000RPM on the 7.3L there is also some mechanism that must engage (throttle valve closing?) that activates engine braking for real as it suddenly gets stronger. But it's not that much stronger, like I said maybe 20-25% than the 2.7 eco. And as RPMs go up the gain in engine braking strength is about the same as the 2.7L maintaining that 20% gap. Only this time when Godzilla enters 2nd gear and 5000RPM it is many multiple times louder and more obnoxious than the 2.7 and only for very marginal increased engine braking performance. So In this circumstance I switch to M and go to M3 and lose braking performance compared to the 2.7L, and it is still louder than the 2.7L but only a little bit. In this gear I burn more brakes on my truck and trailer. Also the F250 computer likes to drop to 2nd much more abruptly than the F150 in Tow/Haul. Maybe as I learn the truck I can find a brake pedal modulation that helps to control for this. Anyway, this makes me wonder if the 2.7L is using the turbos or EGR to augment engine braking. Over the years I've seen lots of 5.0L Coyote owners comment on the forums how their engine braking is much better than the 3.5L eco and I've applied these statements to help make my F250 purchase. I now find this very hard to believe given my 2.7L vs 7.3L experience.

 

I just did the I-75 trip from Cincinnati to Knoxville
towing 10,000 lbs with a slide in camper in the bed and I towed with 10th locked out and walked right up those hills. With a 3.55 gear!

i NEVER tow with cruise on especially in hilly areas

 

That's good news to hear. It seems I may have an issue then as I am seriously underpowered in 9th. I think I have a little more frontal area than you but less weight and on hill climbs weight matters a lot.

I am going to try to see what telemetry can be accessed from OBD2 readers and wait for more responses here, then take my truck to the dealership to see if they can find anything. Thanks.

 

Just curious if you have the permanent locked passenger hub on the 250.

 

I guess I should be more specific, sure I down shifted to 8th a few times and I don't run the crap out of my stuff towing heavy so on the big hills I was ok in an occasional 7th and 60mp. Sure I could run 75 up the hill if I wanted to but I care about the longevity of my equipment. My entire trip loaded southbound the top speed was 65 mph and that's by choice.

you also stated it was a lot of "work" driving without cruise and planning for the hills. Well that's Exactly why I don't use cruise so I have to pay attention when towing etc. I'm in control

 

Sounds about right. I don’t think there is anything wrong with your truck. They are underwhelming in high wind and when you hit grades. I think a lot of people coming from turbo anything feel the same way. 🫤

 

I do. It's a 2024 F250 STX and the driver side hub is set to Auto. In neutral and coasting the truck rolls about the same as my F150. In drive and coasting there is a noticeable difference as I alluded to in my engine braking comparison but I don't understand the possible mechanisms why. Engine size? Drive train? Hubs? All of the above? Don't know.

 

Engine size. There is more pumping losses.

 

I pulled more than double your weight at the speed limit up Monteagle in TN and was able to maintain 55mph just fine. Do not tow in cruise. If the truck is pulling 4k rpm in 4th or 5th gear who cares? That 7.3 will far outlive a 2.7l twin turbo engine doing the same work. There is nothing wrong with your truck it is with your driving style.

 

Where I'm coming from is my 2.7 F150. Towed my travel trailer around 7000 miles over 3 and half years to various state and national camp grounds. The vast majority of that time I could put it in 8 with CC, park my foot on the floor, and enjoy the drive. It didn't make me an unattentive driver but I sure was a comfortable one. Now I've lost all of that and it's hard coming from that place to this new place.

 

Yes 4K RPM will get me up the big grades but the cabin noise is so loud there goes any normal conversation or any chance of hearing my wife's pandora playing on the speakers (not necessarily a bad thing ). It's a concession that didn't exist on the 2.7L and I certainly expected the 7.3L to be louder but I was off by quite a bit. I just have some adjusting to do.

 

It's not the first time this has been reported. Here's another thread comparing the towing experience to the 3.5 EB both with 3.73 gears: https://www.ford-trucks.com/forums/1...nder-load.html

I think you just have to chalk it up to the difference in turbo'd engine vs NA engine towing experience.

 

Hadn't seen that forum thread and it damn well duplicates my own experience, thanks. That dead pedal feeling is legit too...

 

One more question for any knowledgeable engine people here. My planned strategy going forward is to be in Manual mode using M9 on flats/downhill and M8/7 for most hill climbs where there is just enough power to maintain speed or bleed speed slowly. In nearly all circumstances I will be pushing the gas pedal such that I am demanding the full performance of that gear and without the computer dropping the gear. Is this bad for the engine? I am essentially lugging it am I not? Should I instead always be selecting a gear where there is available power on reserve? Note that RPMs will be 1800+ using M9 and 2200+ using M8 and beyond. Thanks.

 

It will downshift in M if it needs to. It won’t let you lug it. In my experience, I can use cruise control and just lock out gears if I need to. If I see a hill that I think will be an issue I just put my foot in it preemptively.

My guess is that you will get used to the high revs and everything else. It’s not actually as loud as you think it is in terms of db. It’s just different and unnerving for a while. That’s probably why you stop listing to the cabin sounds. You’re focused on the engine coming apart, lol. It won’t. Before long you will stop worrying about high revs up a hill and carry on with your business. I think the transmission learns in tow mode as well. I am pretty sure mine is more predictive of hills in cruise control now. It’s no turbo engine though. It really suffers at altitude.

One thing you did not comment on was stability. If you hit high winds at highway speeds the super duty is more stable than the half ton. Better brakes too. If you want gas, there’s some trade-offs between the half ton and the super duty.