Gear ratio vs Tires

[Von Baron]

I had bought my 2006 Ranger/Sport not knowing what I was getting into... I have several other posts here in the site. I am trying to get the truck back to stock as much as I can. I wanted a nice looking, economical everyday driver. I put close to 80 miles a day. The stock tires say P235/75/R15 what I have now on the truck( the way I bought it) tires are 31x10.5 R15(267/76/15)
Now I know all Sport models run 4:10 gearing. I am getting very crappy gas mileage and running 2500 rpm at 65mph. If I go faster, it only gets worse and I feel the need for another gear. It does have overdrive, which I am in all time. Any one know, if I want this an everyday driver... Do I change the rear gear ratio to 3:75's and go back to the stock tire size??? I am getting roughly 16mpg with a 6cyl/17 gal tank. this is no good as my stock Hemi 8 cyl Durango gets 16-18 mpg. HELP!

 

[kirk3000]

You could change your gears out for taller ones, increase diameter of your tires or go 5 mph slower. All will drop rpm's on the highway and should yield better mpg's

Rangers never get great mileage regardless. Im happy with 16 mpg.

 

[Original_Ranger84]

Which motor do you have? With the 4.0L you can do 3.73's and it would improve your mileage but if you have the 3.0L I would imagine there is something wrong with the truck cause I have a 3.0L and 3.73's and I can get around 23 hwy going around 60 - 65...

Also do you have a manual or auto trans? With a manual the rpms for the speed sound about right.

 

[Bennybooster]

2500 is pretty low, I cruize at 3000 all of the time for the best overall milage. My truck will be racing next year and I will probably cruise at 3500 or a bit higher

 

[bilzy7]

I get about 14.5-16 mpg. If I go above 65 my mileage is so crappy. I have 217k miles on it though. not sure what gears I'm running.

 

[RavoHimself]

i have a 4.0 and get 20mpg on the highway at 70mph with 32's and 3.73's. at 65 i can probably squeek 21 or 22. at 65 i'm only running 2200rpm. its a manual tranny which is always better for mpg.

my brother on the hand has a 4.0 stick with 3.73's and 31's and get like 23 on the highway and 19 around town.

best suggestion is to drive the speed limit, inflate tires properly, do a tune up if it has been a while (plugs, wires, oil, clean the MAF), go to 3.73's if you want to lower rpm's on the highway. also if you have a stick then lower your shift points. i shift at about 2100 and get about 16/17 around town.
or if you definitely wanted to see improvements but spend a little money and if you have a 4.0 you could look into this
http://www.compperformancegroupstor...uct_Code=49-410-8&Category_Code=FORD466Cams40

they boast an added 3-4mpg due to the increase in torque. my brother just got one and i'm getting one in the spring. if you decide to get the cam. which i would. then make sure you get cam shaft break in lube

 

[mdn14]

If you have the 7.5" axle and have 4.10 gears I will buy them from you! Haha.

 

[bilzy7]

I have the 8.8 with what, 4.10's? 99 4x4 off road 4.0? I gotta google it...

 

[Downey]

its cheaper go to a bigger tire. i would go to a 32inch tire.

i get 20 mpg on the highway if i stick under 60 running 3.73s and 31s


if i run 70 i get around 18 so your mileage is about right


if you go back to your stock tires size it will only increase your rpms on the highway.


is your speedo right? since it doesnt have stock tires on it?

 

[Captain Ledd]

is your speedo right? since it doesnt have stock tires on it?

THIS. Do you know if they re-calibrated the speedometer?

I'd just drop back down to the stock tire size. If it feels like it needs another gear then it probably does, you're using a lot of throttle to keep it there and consequently fuel.

Lower RPM's don't always directly correlate to better fuel economy.

 

[bilzy7]

I have 265/75/16 and my stock size is 245/75/16; not much of a difference. I know my speedo is right. My engines just old so it's trying so hard, when I'm 70-75 cruising I get like 12-15 mpg. If I'm like 60-65 I'm getting good. That 10 mph extra my engine doesn't like, and my tranny sucks so that doesn't help. Like they said, if you never have, do a spark plug/wire/clean you MAF if you dare.
Ohh and I cruise at around 1800-2000rpm at 60ish, and around 2500rpm at 70+.

 

[bilzy7]

Only thing off on my truck is the stupid fuel gauge, it's below E when I full up and only take 15.xxx gallons. I know now I have 2 gallons when I'm on E or right below.