I'm selling my F350 and I used it for haulling a 30' Travel Trailer...I got 10 MPG normally; when I was in head wind or really moving fast got it down in the 9's... Empty 11-12 depending on turbo use ...don't know gear ratio, but I will find out and let you know
The only way a 4.88 geared truck (no matter what modifications) gets 17 mpg is on the back of a tow truck.
I drove a 2008 4.88 geared 450 for a weekend as I was going to buy one- 12 mpg unloaded is a stretch based on my experience- maybe if you live in the country with very little stop/go traffic and really take it easy on her.
It is an awesome vehicle but don't expect to get great mileage!
2012 GMC 3500 Denali Duramax 4x4
2009 WW HKD with a big garage
A few toys
I just did a long trip, solo one way 175 miles, using cruise control set at 60mph whenever possible. Averaged 13.6mpg hand calculated with refueling topped off at the top of the neck, engine went through one DPF regeneration. Return trip with 12,000lb fifth wheel in tow, again using the cruise control set at 60mph, averaged 10.3mpg, again refueling to the top of the fuel neck. I rarely use the tow/haul feature with this light of a trailer. Not great but not bad for a 9,000lb dual rear wheel crew cab four wheel drive truck. Actually just about the same solo as I got with my gas powered Dodge half ton two wheel drive pickup.
Wonderful Wife,3 Daughters,2Goldens Gus&Riley
"Never get in a battle of wits with an unarmed man"
I've got the 08 F450 4x4 with the 4.30s, and no mods. I get around 13 mpg empty, and between 7-9 towing my Voltage TH (at 55mph). I'm looking at doing the mods next year since I'm active duty and dont have to smog my truck but once!
As a couple of people have mentioned, you dont buy a 450 for fuel economy, you buy it so you can safely tow damn near ANYTHING! I traded a perfectly good 2000 F350 with low mileage to get this so I could safely haul my TH. I miss the 7.3, but I like the 450s ability to tow far more than I liked the "fuel economy" of the 350. The turning radius is also far more impressive than the 350s.
I have a 2008 F450 4x4 King Ranch with 4:88's. I have put just over 4500 miles on it since buying it in November. I average (hand calculated) 10.48 mpg around town unloaded (The dash shows 11.4 mpg). My trip to work and home is 24 miles round trip and most is spent 45-50 mph. When towing my 2008 Raptor 3612DS (15120 lbs loaded) I got 7.63 mpg on a 759 mile trip (mostly highway). It is great for towing the camper, however do not buy it for gas mileage. I did however pick up 5200 lbs of tile from Home Depot last weekend...in one trip! It did squat the truck...just a little LOL.
1 DW 1 DS 1 DMIL & 2 dogs
2008 Ford F450 King Ranch 4x4, w/4:88's
2008 Raptor 3612
Broke, but happy!