Hi I am looking for better fuel mileage out of my 2002 F150 4.6L with 33' BFG's AT KO's. I have heard of many ways to get better fuel economy but feel that doing the gearing would be the best answer, as I drive like a grandpa.

My question is what gearing would give you the best fuel economy, since I don’t need gearing for hard acceleration? Also if I do it myself how much would I be looking to spend?

Thanks for your help,
Carl

 

it might help to know what gears you currently have in the truck, the lower numerically the better your gas mileage (theoretically) but you can go too low and hurt your overall performance/mileage

 

http://www.rocky-road.com/calculator.html

Cost wise, expect to pay between 120 and 220 for ring/pinion gears (depending which brand you want), if your truck is4 wheel drive, then double that for front and rear axle gear swaps. Make sure the front gear set is reverse rotation if you need it. I personally would go with 4.10, but if you reall want more economy, I think 3.93 would be a better bet. My .02

 

3.90's are available for these trucks. i would opt for 3.73, 4.10, or 4.30 (2WD only) if i were in your shoes.

 

smaller tires would help too.

 

your best MPG gain is free. drive easier. Drive like a grandma. You'd be amazed at the difference.

Next, look into lowering your unsprung weight (that means tires and wheels). Any weight not supported by the suspension, kills MPG.

Lastly is rolling resistance. Smoother, more street like tires = better MPG. Big lugs, like off road tires = worse. A/T is right in between.

Engine performance. Make sure its running at its best. Clean air filter, clean fuel filter, regular service, etc.

To change gears for MPG, isn't the best bet. Unless you can swap em in and out yourself, the price really makes the MPG gains pointless. Many other ways to bump up your MPG. Best bet is driving style. Get a scan guage II or something, so you can see immediate feed back on gas mileage. Helps keep the right foot in check !

Put it this way, driving down the highway at 75 I may average 14.5 MPG

going 60 I am closer to 16.5 or better.

 

Carl, respectfully why do you ask for ways to improve fuel mileage with those big high rolling resistance tires?
The motor is only 262 cu/in and lacking torque to pull it'self let alone those tires.
One, the small motor will turn more rpm and use more gas with a gear change.
Two, lug the motor with less gear and your foot goes deeper into your wallet to get anywhere.
Three, the truck weighs about 6000 lbs +/-.
Need some perspective on what you are wishing to achive.
Any big money spent will buy gas for a long time and save all the hassle.
Good luck.

 

what gears do you have now???


I am suggesting 4.10's at the bare minimum and 4.56's would probably be best for city mileage

 

3.73s if your stock gears are smaller than 3.55s.