With my wife driving my '08 around town and to work she gets 9mpg, and I have no modifications and standard tires. That is the same mpg I got last time I pulled a 10500lbs trailer across the state. On the highway I get 13mpg (empty).

 

i dont have the ones after. ill have to look around the frame to see if they are wired up or something. im not getting a check engine light though.

 

i have a 2000 cc 4x4 i and with around town driving the worst i have gotten was 5.5 mpg with 265 tires on the truck it has the 3.73 gears also the problem is that you never let the truck warm up and get to speed an 8000lb brick pushes hard then with the temp outside the lubes are thick good luck

 

ok so i only have the two before. cant even find the wires for the two after. the inside of my exhaust tip is really black too. any ideas?

 

my 2000 only has the two before and at the parts store said that they only come with the two before the cat good luck

 

Your '99 doesn't have any after the cat. I took mine off also and the 2 stock sensors are ahead of the cat. I have to agree with the idea of the 35's and 3.55's. I wouldn't have anything other than 4.30's with stock tires, much less something that tall. My mileage improved with my Hypertech tuner installed. I've run the 93 octane tune in mine since I bought it (95,000 miles then). It is about to turn over 210,000 right now and I've never ran anything but 87 octane. Last month I pulled a 24' enclosed car hauler to Canada and a smaller trailer back. All total about 5100 miles on that oil change and it was barely a quart low when I finally changed it. I frequently gross 24,000+ lbs when pulling a 25' triple axle trailer loaded with hay. I also have a BBK throttle body and K&N cold air kit installed. Mine averages 12-13 highway, 10.5 city and 8.5-9 when towing if you don't try and outrun every diesel you get beside.My Dad recently bought an '07 F350 CC 4x4 w/V-10, A/T and 4.30's. He checked his mileage a couple days ago with about the same load of hay I carry and he got 7.8mpg. It has about 25,000 miles on it now and mine will outrun the crap out of his. He likes it alot more than his '99 F550 4x4 w/ 7.3 but both trucks average about the same fuel mileage. You have to really baby his to get 12mpg when empty.

All in all though, I wouldn't trade mine for anybody's diesel. Especially when they want 6 grand extra for one to start with, much higher maintenance costs and .50/gal difference here between gas and fuel.

 

so everyone is still getting better mileage pulling a trailor than i am unloaded. so is this probabaly the best im gonna get till i regear?

 

well how many miles are you driving after start up and till you shut off are you idling what is the average speed you run like i said my 2000 around town (if lucky 2 miles till i get to work) i also get about 5-7 mpg if lucky on highway i get about 13-14 and i live in upstate ny temp last week was 9 degrees

 

the whole city is about 10 miles across, so never all that far at a time. i guess i just need to get it out on the highway and see what im gettin. and i usually dont let it run for more that 2 or 3 min befor i drive. its lookin like im more normal that i thought.

 

sorry guy but that 99 is the lowest hp motor of the v10's and friends of mine who have had them never got any better then you. plus thiers are dead stock with no big tire drag like you have.

 

i know. it doesnt have the PI heads. i was wanting to get a port and polish on mine but dont know if its worth the money.

 

it's not worth sending any money on. just drive it till you can aford to upgrade to a 05 or newer 3 valve.

no matter how much you try. truth is ford has this motor very well tuned out from the factory. and i know it for a fact as from my shop we spent about 7k on my 05 and got very little out of it in extra hp. so my only word to any one with a v10 is drive put the bling bling money in the bank.