Swapping newer transmission

[Garrissmike]

Can I put newer transmission with more gears to improve gas milage in 98 ford ranger xlt 4x4

 

[swynx]

you mean like swapping a a4ld, or 4r55e out for a 5r55e?

its not that simple. you would need that computer. they did make a 5r55e in 1998, so i bet it would be pretty simple.

on the other hand if your fancy with tools you could build a a4ld/4r55e/5r55e hybrid

 

[RonD]

Welcome to TRS

I assume you mean Automatic since 5 speed manual should be getting about the best MPG from engine and weight of vehicle possible

1985 and up saw Ranger automatics get computer control, partial control at first, torque converter lock and Overdrive shifting(1987).
In 1995 they got full computer control for all shifting, the 4RXXE, XX was 44 or 55 and was engine/gear ratio related, transmission was the same.

These, A4LD and 4RxxE transmissions were all 4 speeds, 3 speeds with Overdrive

5R was 5 speed, 4 speeds with Overdrive

As far as MPG they would be the same for highway driving, 4 or 5 speed, because Overdrive ratio is the same.

Around town a 5 speed might help a little but wouldn't be by much, 1 MPG maybe.

Adding more gears between 1st and Overdrive is more about power, to try and keep engine in max torque range than about MPG.
Or in the case of pulling larger loads it is still about the torque range of engine.
People install 6 speeds for quickness not MPG
Semi's use multi speeds for pulling heavy loads because diesel engines have a narrow torque range

Look and see what rear axle ratio you have, look here: http://www.therangerstation.com/tech_library/axle_codes.shtml

depending on the engine you have and what you need for driving you may have the wrong ratio
4.10(or higher) is great for pulling loads but not great MPG on the highway
3.45(or lower) is great for highway MPG but lacks power for towing/hauling

3.73 is the most common, OK for towing and OK MPG, but not the best for either

 

[Spott]

Axle gearing should primarily be determined by the tire size on your vehicle. If you have small tires you need higher gears (like 1:3.45) and if you have larger tires you need lower gears (such as 1:4.10). Otherwise your engine will run faster or slower than optimum, and waste fuel.

Also be aware that pickup trucks are not very aerodynamic and therefore will never get amazing fuel economy.

 

[Jimmyrig]

You could, but it really won't gain you much. What enine do you have? What size tires and wheels, and what gear ratio do you have? A canopy or taneau cover could gain you a bit of economy, sizing your tires to your engine and gear ratio will gain you the most. Your driving style also has a huge impact.