POOR Mileage on a Sporttrac 4x4 V6 10MPG

[DAVE WILLIAMS]

My 2001 V6 Sport trac is on a 4 inch superlift on 16x8 inch rims with 275's oversized tires. I have loads of performance mods JBS headers dual outlets Mac air intake Throttle body by ZABTECH, with powerraid spacer, quad spark plugs, 8mm wires with 410 factory gears. If I get 10 MPG in the city and 13 highway im lucky. Gas is killing me. I ready to sell this. I know Ford has issues with gas mileage on their truck and suvs but this is ridiculous.Should I replace the gears with 373 or 456 to compensate for the larger tires.

 

[Chad Merry]

Join the club!!! Mileage is BAD when lifted.

 

[Scott Heckler]

I had all the performance mods and got 16-19 all the time. Did you do a performance tune as well? What is the quad spark plugs? Usually only OEM plugs work well on these engines.

 

[Mark K 2]

Common sense says that if you majorly screw with things that mileage and life expectancy will suffer. Ain't gotta be a rocket scientist to figger that out, boy.



Signed,

24 mpg unmodified ST owner

 

[Johnny O]

Lift and bigger tires will hurt mpg. I assume by "quad spark plugs" you mean Bosch +4's. Multi tip plugs do not get along well with Ford's ignition. It would probably help a little just to put in Motorcraft or Autolite double platinum plugs. The Poweraid spacer isn't doing a damn thing for you.

4.56 gears might help a little. With the bigger tires the engine is running below it's optimum RPM most of the time. Also you have TOO MUCH exhaust. A 4.0 is about 232 cubic inches. The stock manifolds flow pretty well but keep the headers since you have them already. Get the Random Tech Y-pipe, maybe a high-flow cat, and just run a single 2.5" system with a Flowmaster or whatever muffler. With too much pipe you lose the extraction effect and it actually hurts performance and mileage.

On my old '05 Trac I had 3.73 gears, 265/75 tires, TT/shackles, and got about 12 mpg, maybe 16 on the highway.

My new '08 has 3.73 gears and stock 245/65-17 tires. I added a Gibson single exhaust and get a solid 22 mpg on highway trips if the roads are level, 20 mpg if they're not.

Don't bother trying to sell it unless gas goes below $3 a gallon, you won't get a hill of beans if you even get any takers at all.

 

[Richard Kolb]

I have a CAI, highway tires, and I get 25 mpg on the highway if I keep it at 60, 20 around town.

 

[Michael Cacioppo]

ironmaiden, has your odometer been recalibrated for the larger tires?

 

[user 64972]

Sounds like Mike C could be on to something. Be nice if a recalibration improved your mileage significantly!



Gary G

 

[Dave S 2]

Imagine that!!!!!!

An ST with poor MPG...

 

[mookie]

Larger diameter tires will register less miles on the odometer than actually travelled.

 

[Woppy V]

so your getting about 250-260 miles per tank???



you just made me feel better about my 350...

 

[Gypsy me]

I don't get bad gas miledge. But I agree with lift and bigger tires will not help. When I run the 20's I have to drive 2 mph higher than with the stocks on. I definately would go back to the Motorcraft plugs again, I pretty much agree with all Johnny O said. Fancy does not always mean better for your engine. And sometimes less is more.



Changed out your fuel filter lately? (it may be time) Ever had the fuel system checked out?





this link below will help figure how fast you are really going with the tire size. I am not sure about the lift. You could go to a shop that does lifts or call them to ask about the lift and your speed. If they want you to bring it down so they can test it...ask how much. Ford shop could do the same for you again ask how much to do that for you.



From the FAQ:

 

[JohnnyB]

With it being lifted and big tires you are doing pretty good. With my '01 ( I no longer have) I got 10.5 mpg combined over 6 years with a stock 4.0L and a K&N air filter.