Dave, I am in your area and in my 2003 V10 X I am getting 11.5. I am not sure of my gear ratio though. My wife drives ours to work in Ripley about everyday. If you go by Steve Westfall's State Farm you will see it. I just got back from Parkersburg this evening and the X was smooth as glass coming down the interstate, I hope you get your vibration figured out soon. Good Luck.

 

I get 12 average driving. 4x4 with 3.73 and all stock.

 

Guys, I really do appreciate the feedback. This board is my "therapy". I should clarify my vehicle history as I have had several. I will narrow it a bit to the Super Duties. The first was a 99 V10 SC 4X4 5 speed with 4.30's and 305's as well. It averaged 10-11 mpg on the same drive I have now. After that was a 2003 F250 SC 4X4 with a 5.4 auto and 3.73's bought new. It averaged 12 mpg. I traded it for an 03 F250CC 4X4 7.3 auto. I progressively modified it until I ended up with 315's, Superchips tuner, cold air kit and turbo back 4" exhaust. I drove it to Florida and averaged 19 mpg (that was with 305's). That same configuration had me averaging 15 mpg on my current commute. I was forced to sell it due to financial reasons. I bought my X for $8500 and it needed work but it has proven dependable. There are two real reasons I want another X. One is for the mileage (diesel). Two is to find a Limited. Mine is an XLT and I just miss the leather. I will say, I have always been a fan of the V10 and it is a strong motor. My boss I raced was in an 08 F150 with a 5.4 and I more than held my own. My driving habits are not the best as I run 75 mph on the interstate and the 10 is humming with the 4.30's. BTW- shame on me in regards to the o2 sensors. I have "intimate" knowledge of their function. I work for the largest OEM supplier and have access to replacements. That may just be my next best bet maintenance wise.

 

Mine too. 100% stock. Best I can do in the city is 8-9 mpg. I have had the truck since new in 2001 and it has always remained the same so I would say that there isn't anything wrong with the OP's truck mechanically.

 

Same here - stock 01-V10. City I get about 8. Hwy about 13-14 and about 10 mpg mixed driving.

 

I did a post about O2 sensors and gas mileage a month or so ago, The consensus was no change. My mechanic has an X and when he changed his O2 sensors he said there was no change in mileage; he recommended I not change them. I had a rear end noise on vacation over Christmas. While they were in there, I decided to go on and switch to 4.30's. It certainly does kill the mileage. I haven't driven mine since I got back but I'm afraid it is going to take a hit.

 

I get between 9-10mpg with my v10 with 4:30's. I took a trip last spring with my travel trailer with a pretty good headwind, was getting 6.5mpg. I have had it for 4 years now and have no plans on getting rid of her!

 

MY $.00002

Driving style has the most impact on mpg no mater what the vehicle/engine combo....

(all other things the same and assuming mechanically sound )

I know I can get 2 to 5 mpg better on mine if I don't use all the tuning put into it

 

The F-series springs make it sit taller and the 305's raise the truck another 1/2".
Additional height means you're plowing more air and probably means the underside is aerodynamically dirtier too.

Your speedo reads correctly now. Which means that before the 305's it was reading low. So your old MPG calcs were actually done at a lower speed. See what your MPGs are at 58 MPH.

Five mostly small changes, but they add up.

 

I'm thinking max the tire pressure's out,,,,thats How I run my SuperDuty all the time,,,,Not that the mileage is very Good even with that,,but it may help some!

 

When I first my Ex a month ago I got 80 for a half tank of gas!! Like 4-5mpg for intown and highway driving. I was pretty pissed to say the least. I took it down to the shop and they did a gas system and injector cleaning and now I get 11-12 for intown and highway driving.

Maybe that will help????? The only issue I have now is no matter how I drive I will only get 50miles for the first 1/4 tank. It is weird but I can not figure out why it sucks it right away.

 

HEY CROOZER, ON A SIDE NOTE, I'm looking to go to th e315's but with a 2.5 front level. What type of clearance do you have with the 4 " ?

Thanks.

BTW. Stock form I am seeing 7.5 loaded (30' Raptor) and 10.5-11 unloaded and cruising.

 

+1 for the driving style. 75 mph with the aerodynamics of a brick will certainly bring your mileage down.

Drop it to 65 mph and you'll see at least a 10% gain in MPG.

Not sure how much your larger tires are hurting you, but assuming you keep your foot out of the go-pedal, you should be getting better MPG than what you're seeing.

I just got back from a weekend of snowmachining-250 miles RT with the X pulling my 26' trailer with 3 sleds, 50 gallons of gas, all the food and gear for 4 days. 4 wheel drive the whole way, average speed about 55 going up, about 60 coming back. 5 Star "Towing" tune-netted 7.9 mpg for the trip, including about 1/2 hour of idling, and another 1/2 hour of hard work pulling a Ram with a 2 place trailer out of a ditch.

The tuner gave me about 1 mpg better mileage on my commute (using the economy tune). I'm regularly pulling 11 mpg commuting. Mix of highway and city.

 

That's a great start, the Triton and other Ford motors I've worked on have greatly benefitted from either SeaFoam or Berryman's B12 in the tank. Seafoam is more of a solvent and will dissolve any type of gunk or grease that it comes in conatct with. Berryman's B12 is extremely potent and will not only dissolve gunk and grime, but really burn it up. If you have an engine that takes forever to start, B12 will greatly reduce the crank time if you know what I mean.

When I'm working on a neglected gas motor, I always run SeaFoam through the intake, then through the oil, a full dose of B12 in the tank, drive it like I stole it, clean the IAC, change the plugs, oil, and fuel filter, and after that they all run like a brand new engine. You'll spend about $100 give or take, but it's totally worth it when your truck is running at it's best.

 

Thanks for the info!! I am new to this so if I sound dumb sorry. What is the IAC? How do you run the SeaFoam through the intake? Would you recommend doing this even after the shop did the cleaning???

I have used Seafoam before in my suburban by putting it in my gas tank but did not see a difference and then I added a cap full to my oil in my Impala because of lifter knock and it cleared that up.