Thought I'd share my first fuel mileage calculation on my '04 F350 RC 4x4 V10.

Though I've had the truck since August, I'm just now getting through the break-in miles. I didn't see any use in calculating the mileage until the motor was broken in.

I drove back from the In-Laws to my home in Baltimore. It was 199.5 miles of mixed driving. There were stretches of 75-80 mph cruising, stretches of slow-and-go construction zone, some in-town driving at both ends of the trip and a couple rest stops in the middle. The trip was about 60% flat and 40% mountains. (Well, what passes on the East Coast as mountains.)

I drove directly home and filled up the next day - 15.24 gallons. That's a little over 13 MPG. That's not bad for a "gas guzzler" that's barely broken in. I was expecting something closer to 10.

With several complete stops, four engine startups, and at least a half-dozen hard-throttle accelerations, I figure I must have been above 15 mpg on the highway to average 13 for the trip. Wish I had a damn computer on the truck that read instantaneous mileage. Guess my $30k wasn't enough to cover that $25 item.

 

These beasts do pretty well considering their 7K plus weight.

I ended up taking the wife mobile (Grand Marquis) to visit the outlaws. We got 22 mpg in it. Very good for the size car it is.

 

That's good. I love it when people act stunned that these things get the mileage they do. I had a guy at work tell me I was crazy for not getting a diesel because V10 Fords get 9 mpg. I'll bet your mileage will continue to get a little better. I got 29000 on mine but it seems like my mileage took a 1/2 to 1 mpg jump when I got around 10K. The other thing is I make sure my tires are aired up as much as is allowed-I think that other than being a good driver the tires make the most difference!

Lots of misinformation out there.

I get 11 to 12 mpg for mixed 50/50 city/hwy driving and get over 14 easily on a highway trip not towing. That's doing about 65mph & keeping it OD as much as possible. A few times I even got a little over 15 mpg on trips where I drive a little slower. Alot of the guys I know locally with PSDs are only averaging 15 to 16 mpg mixed driving.

 

I got an 04 fx4 cc 430 v-10 auto . It now hase 1 size larger Tires and with 007156 miles on this truck in cruse after MANY trips to S.A. from waco 186 miles i still only get at the best 8.9 m.p.g. that is no B.S. Ford told everything is fine except for my over sized tires that is why mpg sucks!!! I say thats B.S.Any thoughts on that one? thanks..

 

Did you have your speedo calibrated for the new tires? Larger tires roll further for each rotation and may show an indicated mileage lower than it actually is if you didn’t adjust the speedo.

 

Yep, unless you recalibrated the instruments your'e getting better mileage than u think. I have 285/75 tires on my stock wheels and my mpg is right in line with most 4x4 V10 owners. I got the odometer/speedomter adjusted at a Ford garage The other difference is I have a K&N air filter and the 3.73 axle-which I got specifically instead of the 4.30s for the better mileage. My trailers only weigh 7000lbs at most and the V10/3.73s handle that fine.

What size tires did you get?