Gear ratio to lower engine rpm

[Ranger Dolly]

I have an 09 fx4 and would like some feed back on changing differential ratio to reduce rmp to improve mpg and cost to do this

 

[2011Supercab]

Need to know what you have now.

Gear Ratio, Tire Size, looks like you have an automatic.
What Speed and RPM do you normally run?

 

[Ranger Dolly]

Automatic with 4.1 lsd with stock wheels and 255/70/16 Michelin ltx. It runs 2500rpm at 70mph

 

[rusty ol ranger]

Also being 4wd youll have to change the gears in the front and rear axle

 

[Ranger Dolly]

Yes and wondering if the cost of doing this would be worth it. Seems to have lots of power for my driving.

 

[rusty ol ranger]

Yes and wondering if the cost of doing this would be worth it. Seems to have lots of power for my driving.

No.

You wont gain much in mileage...youll wear the truck out before you ever see the money back you spent on gears.

 

[Ranger Dolly]

I expect you are correct

 

[Ranger Dolly]

Just like to match a 5.7 hemi ram 4x4. Wishful thinking?

 

[Blmpkn]

Could always put bigger tires on it.

 

[Ranger Dolly]

Any suggestions for stock rims

 

[rusty ol ranger]

Just like to match a 5.7 hemi ram 4x4. Wishful thinking?

You should be getting close to, if not better MPG then that...unless its got an 8 speed

 

[Ranger Dolly]

It has the 8 speed auto

 

[19Walt93]

A lot of questions need to be answered first but it's unlikely that you'll save enough on gas to ever pay for the gear change. First, what do you get for mileage now? Is your area flat or hilly? How much is highway driving vs. secondary roads? How much weight do you carry? My 2004 Ranger 4x4 / 4.0 / 5 speed with 4.10's routinely got 20 mpg on gasoline and dropped to 19 on E10. My 2011 had an automatic and 3.73's and it was more like 17-18 on secondary roads. I found that switching to Mobil 1 helped the mileage, as long as gas cost at least $2.80/gal the improvement in mpg offset the extra cost. Driving habits make a huge difference, acceleration is fun but it's expensive. Tailgating causes you to brake often and then accelerate back to speed, back off a little and save some gas money as well as your brakes.If you do a lot of stop and go/ city driving, stop checking the mpg.

 

[Ranger Dolly]

I currently average 18mpg. Drive very gentle and use torque rather than hp to accelerate. Driving is a balance of 4 lane roads and 2 lane with 10 % on logging roads

 

[19Walt93]

I look at gas mileage differently than most people, I guess. When you buy gas you're turning cash into gasoline, accelerating turns gasoline into power/speed, braking turns speed into heat(and brake pad wear). Then you turn more gas into speed again. Tailgating burns more gas and brakes. I coast down a little before exit ramps or stops, my son stays at speed then brakes hard. He buys more gas and brakes than I do. I check my tires about twice a month and don't carry a bunch of extra junk. Oversized aggressive tread tires hurt mileage, too, because of rolling resistance and the extra weight that needs to be kept turning.