Hello, new here. Just picked up my murdered out 2000 Ford Excursion V10 a week ago. Guy I got it from said it gets 10-12 MPG.

He was running it with 22" wheels and 37" tires at some point (so maybe that is where he is getting 12 mpg), but it now has 16.5" welds with 39.5"x15" swampers on it.

Speedo is off a bit as the most the superchip (or the dealership) can electronically set the tire size to is 38". Still, accounting for the difference in tire size setting it appears that I am getting appalling gas mileage. I am told it has 4.56 gears and I am doing city driving light to light, almost no freeway driving at this point. I had to drive it home from about 3 hours away and I was getting about 10 MPG (so read the comp gauage).

I know you are not supposed to trust the computer read out but it appears to be correct so far. A fillup from empty with warning light was 35 gallons, I have gone about 60 miles and read about 3/4 full, therefore a 1/4 tank is 8.75 gallons and 60 miles/8.75 = 6.85 MPG. If speedo is set for 38" tires then reading is off 38/40=95% so 6.85 MPG/.95=7.2 MPG.

7 MPG is just unacceptable, isn't it? I mean, I normally drive a V8 suv and get 16MPG and I am ok with that, and this thing is huge with big tires so it will be worse, and I am ok with like 12 MPG, but 6 mpg is just unconscionable, isn't it?

I am not burying my foot in it; I have it in 2wd. Is this reasonable given my setup or is there maybe something wrong? If this is reasonable then will getting some 37"x12" radials help much?

I am feeling really guilty about this purchase now, I was ok with it at 12 MPG, but 6 MPG I don't think I can live with just to drive around, not towing or anything etc. If this is SOP I will have to sell it I think. I mean, I might as well be throwing money out the window to watch it blow away at 6 MPG.

Looking for other lifted v10 owners to validate. Thanks for your input.

 

Yikes...

And welcome here. I'll let the gas burners chime in, but, what is your cruising rpm?

 

I think cruising rpm is just above 2k.

 

I run 35" tires and upgraded to 4.10 gears for a close to stock result. Your gas boys, and girls, all say the V10 likes to rev, which yours won't with 4.56 gears and 39.5" tires. You have like triple overdrive and should drive over one hundred miles an hour to increase your mileage...

Time for new gears, or shorter tires, then less lift. Pictures?

 

 

Really? This is the first I have heard of this. I thought the 4.56s were necessary for tires this big to keep it near stock ratio. The guy I got it from did say that he drove it around town with overdrive turned off. I hadn't ever heard of a higher revving engine getting better gas mileage. I guess I will try that. I can also raise the shift points about 10mph with my superchip device.

 

Looks nice, you shold pull the cross bars off the roof rack or the paint will be abused. May be already. Not much clearance.

The V10 crowd must be sleeping in today. Do a search on V10 and higher rpm, that should give you more info.

 

Umm yeah, that combo might not net the best MPGs.
Cool looking rig but that sky high lift and those monster tires have "murdered out" your aero drag and rolling resistance. A lot of us V-10 folks only report 10 MPG or so with all in town driving in stock trim. With your tire size and gear ratio your effective gear ratio is a wimpy 3.64 ( I use this online calculator 4Lo.com :: Tire Size Change, New Gear Ratio Calculator ) With that high of a ratio you are having to lay into the skinny pedal to get all that heavy rubber moving from all of those stoplights, there goes your MPGs. A deeper gear would give a better torque multiplication and would be easier to get the big meats rolling. Dropping down to 37"s will help some with an effective ratio of 3.88, still not all that great with big rolling stock. 5.13 gears with 37"s would net an effective ratio of 4.37, that would be a pretty decent combo with better performance and probable better mileage due to less lugging of the motor, these V-10 don't mind revving a little. My rig gets better mileage towing with my 4.88's than it ever did with the factory 3.73's.

 

I used to get 13 mpg with 37 in town driving with my 7.3l diesel with only 6 inchs of lift. 7mpg out of a v10 in town driving with your setup doesn't sound to far off from what you will get. as far as driving with od off that wont help your mpg, but lower gears can. It will make it easier for the engine to get you going. 4.30 gears in stock truck get better mpg in town then 3.73 sense it takes less effort to get you rolling. I have a v10 now and 10 mpg in town driving only is pretty common for theses rigs. They are big heavy and have 10 cylinders to fuel. I would do a tune up and change filters clean you mass air sensor but you wont get to much better fuel millage. Also get a gps and check your speed vs you speedometer. If you have a smart phone you can download an app to get your speed. That might be where your getting some issues. I remember on my sd I had to get a external speedometer corrector to get the correct speed.

 

10-11 mpg city only driving on a stock X here - 4.30 gears

with my lifted F-250 and 6.0 PSD I was getting 12-13 MPG city only driving on 35's - 3.73 gears


6-7 mpg seems about right to me for that lift/tires

 

You cant have bought a massive SUV with those gears and 39.5" tires and expected double digit mpgs...i think

 

hell i get 7 mpg with my nearly stock in comparison excursion all winter long. i say your LUCKY to be getting close to 7 with that truck.

with a stock V10 4x4 3:73 Excursion i have seen 8-10 mpg city and 11-14 mpg highway. for the last 4+ years and 45,000 miles. my daily driving is mostly city driving and i dont see double digit mileage unless i'm on a road trip/highway run.

with your current mods, your not going to see much better IMO.

my average MPG is 8.9 if that gives you any indication of what to expect. i have stock sized tires.

 

Mr Mo,

First, welcome aboard. This is a great forum, with remarkably few knuckleheads, and a lot of great people. You can decide in a moment into which camp I fit...

Second, I'm a 7.3 guy, with zero real world V10 experience. I do love me some measuring tools, though, and you are putting way too much faith in several:

Gas gauge - Just because it reads 3/4, doesn't mean you've used a 1/4 tank. Fill the tank to the brim, drive for a known number of miles (the more, the better), and fill it to the brim again, from the same pump. Divide miles traveled by gallons used to get your actual MPG. There is no other way to do it.

Tire size - I know they say 39.5, but my bet is they are very close to 38". Measure across the tire (not from top to bottom) to get a rough idea of their actual diameter.

Superchips/dealer - As I've demonstrated to myself with AE, the tire size you tell the PCM isn't necessarily the actual size of the tire you are running, it's just a factor to make the speedometer read accurately.

Speedometer/Odometer - Based purely on the info in your post, I submit to you that you don't know how fast you are going, nor how far you've traveled. If you have a GPS you trust, see what it says in steady state driving over 40mph, and compare that to your speedometer. Or, you can hang the speedo on a certain speed and time a few miles on a highway with mile markers. Either way should get you really close. You pretty much have to do this for any fuel mileage calculations to be correct.

I'm not really into lifted Excursions but, if I were, I'd be drooling over yours. It really looks nice! More important than what I think, you like the truck, and you own the truck. Before you dump it, do the work of figuring out what mileage you're really getting, and then figure out what that mileage really costs you. (For example, if you drive 10000 miles per year, and gas costs $3.80/gallon, the financial difference between 7mpg and 10mpg is about $1600 per year.) Forget the notion of unconscionable: It's just money, and it's either worth it to you to drive this thing, or it's not.

Sorry to rant or lecture, those are traits of my internet persona, not my real one. You have a nice truck, and I hope you're able to enjoy it.

Mark

 

i 100% agree. check your mileage via GPS. hand calculate true miles driven VS gallons used. thats the only way to know for sure what your true mileage is.

 

Also don't trust the mpg gauge in the truck