31" tires on my 96 2wd 2.3L 4cyl 5spd Ford ranger

[henryj10]

Been playing with the idea of getting 31" tires on my 96 2wd 2.3L 4cyl 5spd Ford ranger. Got people telling me 3.73's people telling 4.10's and people telling me 4.56 gear changes for better fuel economy with 31" tires. From what I see on some of the gear charts 4.10's seem to spell fuel economy with 31's. You might have noticed I went from 29's to 30's and now to 31's if you seen me on here before I'm sticking with 31's now. I'm not expecting great fuel economy but I want to get the best I can. As it is with my 96 8 spark motor I get low 30's, wanna get the best i can. I'm kinda thinking 4.10's wanna know what some of you think?

 

[strvger]

with only a 4 cyl, you'll be happier with lower gears. i really like my 4.56 gears. and i also run 31inch tires but they are tall and skinny: 215/85x16 at's. those do get me a little more mpg's over the really wide off road type tires. and being E-rated with stiffer side walls helps, too. getting 21 mpg on the highway with a lifted 4x4 and a 27 year old 2.8 v6 so i'm happy. but that's just me.

 

[Original_Ranger84]

What you want to be looking at is torque. how much torque does your 4 cylinder make and what RPM range does it make that in compared to a 4.0L? A 3.0L doesn't have a bad amount of torque but since you get it about 1000rpms higher then the 4.0L motor the truck has a much harder time at take off and shift points are altered.

The 2.8L motor is a sweet little motor that seems to infinate torque (or atleast mine feels that way.) Where you will loose mileage is at takeoff and the more you struggle at take off the more fuel you will use and chances are you will be struggling to get up to speed if you ahve to slow down or encounter a hill.

I would say go with 4.56's like strvger said because it is a much smaller motor ande will help you get a good mix between power and fuel mileage. (although something like a 4.30 gear ratio would better suit you they don't make it.)

 

[davej87]

im in the same boat as you, 4 banger 5 speed, i want posi rear end, so i was looking for a differ gear ratio cuz i have 29s on it, im still wondering if the 410s or the 373s are better and if i should go with the 8.8 axle rather then the 7.5

 

[Ranger Sport Honduras]

my truck has 3.73s gears with 30" tires right now, and considering the 2.5 has more power than the 2.3, it feels a bit slow with them. so 4.10 gears would be a good ratio for 30"s and i think it would still work decent with 31"s

as for axles, the 7.5 will hold fine with 31"s

 

[Nater]

I ran for a while with 31s and a 2.3L with the 3.73 rear....

 

[Randysbamaranger]

I have a 98 Ranger with 2.5 4 banger. I am running 4.56 gears with 31" tires. I am getting 20 mpg. I am happy with my gears.

 

[JFox4]

I think it depends on what your purpose is, im figuring out the same thing and getting ppls advice. Ranger sport gave me good advice and just said wait and see what you think. Every person will have a different reaction but i do hope im ok with 3.73 gears, but if i need to re gear i will.

 

[CountryBoy704]

i've got the 2.9 v6 with 235/75/15's 3.73 gears and i get 25 mpg, here's the key i think you're looking at - gas mileage and acceleration go hand in hand, lower gears give you more tourque and also slow down acceleration while adding low rpm power, this saves gas in a dd because the added power in acceleration should make up for the increase in rpm at given higher speeds as long as you dont drive like a demon, this can work against you if you demand a quick takeoff as it will drive your motor consistently into higher rpm ranges while accelerating
it all boils down to how you drive it

 

[strvger]

^^ this is partly true. don't forget that going to taller tires has the effect of lowering the axle gears. going to 31 inch tires with 4.56 gears may actually reduce the final drive to something like 4.10 when calculated as compared to the original 27.5 tires. this is an example only and probably not correct, but you get the idea. all the calculators are in the tech library for exact numbers.
and even this doesn't address the issues of larger tires having increased un-sprung weight, increased drag/wind resistance, etc.
that's one reason why i'm driving tall, skinny tires with stiff sidewalls as it all adds up to helping with better mpg's.
the other reason is my tires give me the choice to go around objects in the trails that others with big, wide tires can't. they have to rev up and crash over or try to crawl over big rocks and stumps in their way. that risks breaking something usually important to making forward progress. most of the time i can drive around them if i choose too. i trail ride what i drive to the orv park. it has to get me home after a weekend of trail riding and to work the next day usually. i have fun, but i also have to drive smart.
but that's just me.