I keep hearing this!!!! "wait until they are broke in and then they will get better mileage" I'm not totaly disagreeing with that but I have bought 7 brand new trucks over the last 20 years and at the most I saw a 1-1.5 mileage increase over new. I attribute that to the fact that once the newness wears off you drive them differently. I'm not buying that these new engines will get a significant mileage increase when "broke in". If someone has proof otherwise please post it... I had a 2003 6.0 and I got better mileage when it was new 19-21 mpg on the hwy than when it was "broke in" 17-18mpg. I attribute that to the reflashing from stock. My new 6.0 has only 6300 miles on it and I see from 17-19mpg hwy and I don't expect to get more when it's "broke in" I think that with the new technologies that the engine builders are using today the engines don't improve as much as they did in the past....

Than again I could be wrong but please prove it...

 

I agree they have way more power now and in return less gas milage but that is what they say !!

 

I actually think its possible, definitely on the highway at 70-75mph when your turning 2700 rpms. Problem is, I dont drive at 70-75 that ofter so the payback on 70/30 city/highway just wont pay out for quite some time.

That being said, even if it took 5 yrs to recoup the cost of the unit, the wear on the motor at 2700 vs the lowered rpm on those trips would add up IMO. So whos going to be the first F450 4.88 truck to make the jump. LOL

 

Well I have no new report for mileage, still averaging 11.5 per fill up. I did however get my 5th wheel hitch installed and towed for the 1st time..........

I only was able to tow about 15 miles to the Rv dealer for an inspection, but here are some first impressions....

***1st off the truck had no idea the 5er was even attached, might have gotten 1" sag when the weight was applied. Obviously, 2200# vs 6100# capacity!
***Took it down rural roads, never towed with a dually so the experience was certainly a treat, no lateral movement in the truck at all, very firm and sure handling.
***Tow boss, Ok! Went down a fairly steep hill, tap the brake and it's like a Jake brake....very nice! But, acted like it didn't want to shift up with out coaxing???? Gonna have to get used to this, not sure I like it at this point. Probably just my ignorance.
***The Brakes on this truck are the best ever! Totally solid.
*** Power house??? Even with the 4:88's and a 15k 5th wheel, well let's just say it did ok but didn't seem to have any more power than my prior 7.3, sort of disappointed really.
***The lie-o-meter never topped 7.4 mpg during the brief haul.
***Low interior cab noise, even when your trying to put your right foot through the floor!
***Did I say the brake are awesome, well they are.
*** The vote is out, I need more testing. Currently over all I like the truck but I think if my 99 F250 with the 7.3 would have had dual rear wheels, it would have done equaly as well towing. I already know I used to avg 10-12 mpg towing this very same 5er so I'm not impressed with the potential of getting only 8 to 10 mpg. The only thing that really stands out for me are the brakes. Everything else I'll reserve a final opinion on till I can tow for at least 100 miles roung trip (which will be Mat 17th).

Sorry guys, not bashing as I too own one! Just not blown away like I though I'd be.

 

I like not picking up speed down a steep hill and not needing to hit the brakes

 

I love the engine braking too. Headed west on I-40 coming down the grade from Kingman, AZ was great. Cruise control makes this even better. I had the cruise set at 60 for fuel economy and coming down a 6% grade for ~7 - 10 miles, cruise control applied the engine brake and I never went above 60 MPH, then at the bottom, automatically took off the engine brake and kept on plugging away at 60.

Now if I could get automatic steering, I could take a nap!

 

A Futher Update on my Fuel Mileage. Truck now has 6000 Kms/3728 miles with no problems to date. I operated truck empty during this period with some mountain climb, city and freeway driving. Fuel mileage has increased to 14.08 US MPG, 16.7 L/100 Kms / 16.91 Imperial MPG. The truck does not feel as stiff anymore and has definitely had an increase in fuel mileage. I have a two week trailer trip to WA and OR last half of May and will report the MPG after.

While in the Ford dealership today learned a fellow had 3 miles on his new GT-40 when he totalled it at an intersection with a caddie who busted a red light. His new GT-40 arrived today. It is in the LeMans blue, orange and white. Insurance was for a new vechicle replacement in case of a total. Lucky fellow.

 

The preferred (by many) method for gearing a truck is to cruise at an engine speed above the peak torque rpm, that way when you hit the hills or a headwind and the truck slows, as the rpms drop your torque is increasing which cuts down on the downshifting.
If mpg was better and driveability improved by gearing a Ford Super Duty to cruise 70-75 mph at 2,000 rpm, Ford would build them that way.

 

Quote:

Originally Posted by origcharger

The preferred (by many) method for gearing a truck is to cruise at an engine speed above the peak torque rpm, that way when you hit the hills or a headwind and the truck slows, as the rpms drop your torque is increasing which cuts down on the downshifting.

That's exactly how my F250 Lariat is. At 75 it's just above 2000 with the 3.73's. I now have about 1700 miles on it and the 3rd trip back home from Hagerstown showed me 19.6 on the computer. The previous 2 trips I could not get it above 17.8 no matter what I did. (so far the comp. has been very close to calculations) I tow infrequently with a <10,000-lb trailer and don't have a 5'er yet. It has to work a little harder when it is towing than you guys with the big gears, but that's OK. And our "mountains" around here aren't that big anyway. I love it on the road unbridled and the milage is coming along great. I previously had a 1987 jeep cherokee which I bought new and drove for 20 years (170,000-mi). I never saw better that 23.5-mpg and that was staying below 65. At the speeds I usually traveled (70 - 80) I got 20-21 and with the trailer it was down aroung 15. Who could complain about my psd. I know it's not close to broke in yet, and I love it. The thing that really amazed me was how much sitting at stop lights and idling tears up the fuel mileage, you can watch it go down. Never thought about that until the computer.

 

Strut, did you notice how much higher rpm it ran in tow mode, wondering if that killed the fuel milage? Your Creek is probably about 15,000# loaded? I've driven manuals for 40 years. I read a lot of good things about the Torqshift so I went that route. Still wonder if I am going to miss controlling rpm's myself. Wasn't planning to tow untill Memorial Day. I sure hope I find a big difference in towing. my v10 3.73's was rated at 9800# and my 5'th w. is 13,000. We have a hill leaving the house that I couldn't get out of 2'nd gear at 30mph. Remember your 250 7.3 sw was a lot lighter than your new 450. So we have to pay extra to have that big bad 450. a 250 regular cab 6.4 is only about 6,000# and the 450 is 8700#. So we are hauling around an extra 2700# to start with, and the 250 you can get with 3.73's so it will run a lot lower rpms than my 4.30 and your 4.88. The 450 is King of the Road but we have to pay that extra especially with the 24,000# towing capacity of your beast. Hope this makes you feeel better. Still think you will have a grin ear to ear when you pull into the campgrounds and people say, Wow that guys got one of those new 450's!

 

firehawk, I'm sure (Hoping) its a matter of getting used to it........not really thrilled with any of it at this point. I took the 5er down a very harsh incline about 3/4 miles long and the truck would still be screaming if I had let it. Then it acted like it didn't want to release from the lower gear once on the flat. I had to apply a good amount of throttle just to get it to shift.
Oh not to mention, going UP the hill. I had it in tow/haul (First time) and I was pushing floor boards......this thing with 4:88's topped the hill at the exact same speed my 99 F250 did with 3:73's. WTF!
This truck is beautiful, runs well and that is it! Seriously not happy at this point.
Right now I'd gladly get rid of it for my old truck. Besides that I got 15-17mpg running empty and 10-12 towing the same 5er.
All I have now is a slower dually Diesel HOG that looks awesome, it's kind of like a beautiful woman ya can't stand to be around!! Very frustrated here guys! Geez I hope it's just first impressions, If it's not I'll have a friggin For Sale sign!

 

should've got a Chevy

 

Naaaaa, A GMC there better!

 

Strut, been thinking about the towing while I ran 6 miles this morning. I think, not able to back it up but? When you mentioned that your speed was the same at the top of the hill as your 7.3, I think your 7.3 was at the proper torque rpm verses your 450 with 4.88’s was probably over reving. Example in Mass. On Rt 90 in the Berkshires they call it Blanford mtn. Going up it with my 99 v10 3.73 5 speed stick I ran it 55 mph 3rd gear 3700rpms full throttle. Your 7.3 would probably run 4th gear (if 5 speed) 2300 rpms 2/3 throttle. My new 450 4.30’s should run it 55 mph in 4th at 2600 rpms ½ throttle. Your 450 with 4.88s in 4th at 55 would be probably reving 2900 rpms being out of the torque range. Now change the weight from 13,000# towing to 24,000# my old v10 and your 7.3 would probably be down to second gear pulling their hearts out. My 450 would be down to 3rd gear 40mph at 3000 rpms. And your 450 would still be at 55 in 4th at 2900 rpms pulling just fine. So what I am trying to say, under certain circumstances towing 13-15,000# will be different at certain hills with each setup. Hope this makes you feel better. Just the 4.88 pulling 15,000 might be a bit of an overkill. You might have to go out and buy one of those Tenton homes that weigh over 20,000# to feel the real difference. Give it some more time buddy before you get discouraged.

 

That is exactly why the 450 and 4:88's.......we're looking at a Teton to replace the Creek in a 4-5 year time frame.
I understand what you your saying, still frustrating though.