Best Gas Mileage for modded 4.6L V8's

[jayton]

Hello guys,
I just recently purchased a 2002 Explorer XLT with the 4.6L. I have read thread on this board of the guy that gets over 30mpg in his 4.0L V6 Explorer. What I want to know is what the best mileage you 4.6L guys are getting with similar mods. I am currently getting about 19mpg hwy, and 16-17mpg with my wife's everyday driving to and from work. If I dump a bunch of money into mods geared only towards helping fuel mileage (and a little horsepower along the way , but that is not the important part), how much of a gain will I see in fuel economy?

Those of you that have modded your 4.6L's with the following things:
Cold air kits
electric radiator fan
exhaust upgrades
removed luggage rack
wind jammer or other wind deflector
lower gear
computer flashed
under drive pulleys
lowering
or anything else to reduce vehicle weight, improve aerodynamics, etc.

If I did all of it, what would be the best gas mileage I would see?

As far as the wind jammer or those wind deflectors that aim the air down the back of the vehicle: do these not just cause drag? How does the wind work to your advantage with these gadgets, and which one performs the best?

Thanks,
jayton

 

[IZwack]

The best and cheapest "mod" you can do is to change your driving habbits Its free, and the MPG difference is significant! Accelerations should be sloooow -- pretend like you dumped the 4.6L v8 and instead swapped it for a 1.6L i4 Civic engine
Accelerate on downhills and ease off the gas pedal on the uphills. I know it may contradict what others protest but unless youre travelling in a very flat area, using cruise control does not save on gas as the vehicle tries too hard on uphills to maintain speed. Also, don't just watch the vehicle in front of you, but also the traffic ahead and anticipate any slow downs -- try to coast instead of using the brakes. This means leave pleeeenty of space between your vehicle and the car in front to allow for coasting.

Windjammers do not really help much in aerodynamics. I think most SUVs have them to flow the wind over the back windows to keep them clean. The biggest drawbacks to most SUVs as far as aerodynamics goes is their large "whetted area" and the very blunt/flat rear. The affects of these drawbacks increase with speed. So the slower you go, the less aerodynamics impacts your vehicle's MPG.

 

[random hero]

the brown wire mod (splicing a switch in your elctromagnetic clutch, disengaging AUTO 4x4) helped my gas mileage alot since i can always run it in 2wd. Thats something u might want to look into if u have the AUTO 4x4 option.

 

[rancherlee]

DON'T get bigger tires.
My Mountaineer AWD showroom stock got 14mpg around town, 19.5mpg freeway (close to the window sticker). It needed new tires and I went 1" taller to 245/75/16's from 245/70/16's and my in town dropped to 12mpg and I now get 17-17.5 highway, Even taking account for the 5% drop due to the odometer spinning slower I've lost 10-15% MPG. I just picked up a Xcal2 from vmptuning and hopefully getting the computer corrected for the tire size difference and a 87octane MPG tune gets me back to stock figures or even better. MAC CAI did nothing for my fuel mileage but then again it puts a 90* bend right before the MAF which causes some issues also which will be fixed with the Xcal.

 

[va4wd]

Actually the best way to improve your CITY mileage it to accelerate hard from a stop till you reach your crusing speed, than feather the gas. That way your engine is only under load for a short period of time. This is also fun, but remember to just lightly touch the gas when you reach 35mph or whatever. Also if you need to accelerate from 35 to say 45, again do it quickly and accerate hard, then repeat the constant speed feathering.