F-350 vs F-450

[ducatirider944]

So I'm in the market for a new F-350 dually to replace my 04' F-350 dually. I'm averaging about 13-14 mpg's not towing (combined city and highway) and between 8-9 mpg's towing about 20k#. I have 4:10 rear gears in the truck i own now. I can't find any F-350 duallys with the options I need with in 650 miles. There are about 5 F-450's with the options I need with in 200 miles of me. The deals I'm getting on them are pretty good. The problem I see is that they all have 4:30 rear gears. The F-350's have 3:73's. I want to try and at least keep the mileage I'm getting if not improve it. I'm pretty sure the new F-350 would get better mileage than my current truck. Does anyone that has a 450 mind posting up how you are doing for fuel usage? Thanks

[BIGGDADDYT]

Bumping this up.....

[ducatirider944]

At this point it doesn't matter, I will find out what a F-450 gets for mileage myself tomorrow

[norris]

i was mad the 450 i ordered was only going to be an 8 lug. basically a 350 with a little more tow rating. i couldnt build a cab/chassis with the lariet ultimate package so i had to get a 350 drw. so far my truck gets 16 loaded or unloaded. better mileage on the interstate 70mph + i see 18-20 cruising.

[ducatirider944]

Well the results are in. 250 miles all interstate from the dealer to my house, 72-74 mph the whole way, 12.4 mpg. I don't want to actually hand calculate it because I know it will be worse. I will take the number the lie-o-meter is telling me because I don't want to think about the reality of the fact that I just bought a truck that stickered for $68k and gets 11 mpg

[92f350cc]

That number should go up as the engine and drivetrain break in. Also keep in mind that the engine is more efficient closer to peak torque, so you should be in the 1800-2000 rpm range. 72-74 mph with an F450 and 4.30's is running around 2200 rpms.

[ducatirider944]

Originally Posted by 92f350cc

That number should go up as the engine and drivetrain break in. Also keep in mind that the engine is more efficient closer to peak torque, so you should be in the 1800-2000 rpm range. 72-74 mph with an F450 and 4.30's is running around 2200 rpms.

Those numbers are about spot on

[92f350cc]

Thanks, I like to dabble with Excel spreadsheets and mathematical formulas.

Try driving it at 65 mph on the highway and see what you get.

[PoorMansCat]

Originally Posted by 92f350cc

That number should go up as the engine and drivetrain break in. .

Mine didnt....

[jake1086]

I've been hand calculating mine and I usually find my hand calc are better than the dash... just fyi