Best gear ratio for 31" tires?

[Pod]

I am likely going to re gear my 1998 3.0 v6 for 31" tires and I am wondering what is the best gear ratio to go with? I know the typical gearing for 31" tires is 4:10 but as the 3L doesn't have much torque I was wondering if it is not such a bad idea to go with 4:56 instead. Only thing is I don't want to affect daily driving at highway speeds or anything and I want to maintain my gas mileage for the most part (that's mostly why I am re gearing in the first place). I also have a manual transmission.

Thanks for the input.

 

[Curious Hound]

I really think 4.10 is fine for 31's. 4.56 will feel pepper.

I'm running 4.56 gears and 35's with a 3.0l and 5spd manual. It is almost identical to performance of the factory 3.73 gears and original tire size. I wouldn't mind 4.88 or 5.13 gears. But you would be surprised at what I can do with this combination.

Here's some good info.

Gear Ratio & RPM Guide For Larger Tires - The Ranger Station

This Gear Ratio & RPM Guide will enable you to see how many RPM's your engine will turn based on gear ratio and tire size.

www.therangerstation.com

 

[Pod]

Okay that's good information, thanks. And thank you for the chart as well, very helpful.

 

[scotts90ranger]

On a 4x2 I'd go 4.56 gears, in 5th that puts you at 3000rpm at about 75mph, since you're in the hills I'd recommend that over taller gears, assuming you don't drive freeway all the time... 4.10 just isn't worth the expense unless you grab a junkyard axle and just put it in, that'd be way cheaper than having an axle put in... that said going to 4.10's would put 75mph at about 2700rpm so would probably be reasonable...

I ran 4.10's on my '90 for a few years with 31's and a 2.3L, it was doable but took a lot of clutch work... when I first got into offroading I went through a clutch in 15k miles...

 

[cbxer55]

I'm running 4.10's on 26 inch tires on my 98 3.0, and love it! It's peppy as one could ask for. Just got a set of 4.10's for my Lightning. And that's with 28 inch drag radials. Mustang soon to follow.

 

[Pod]

On a 4x2 I'd go 4.56 gears, in 5th that puts you at 3000rpm at about 75mph, since you're in the hills I'd recommend that over taller gears, assuming you don't drive freeway all the time... 4.10 just isn't worth the expense unless you grab a junkyard axle and just put it in, that'd be way cheaper than having an axle put in... that said going to 4.10's would put 75mph at about 2700rpm so would probably be reasonable...

I ran 4.10's on my '90 for a few years with 31's and a 2.3L, it was doable but took a lot of clutch work... when I first got into offroading I went through a clutch in 15k miles...

I do do a bit of freeway driving and I want to be able to take it on road trips sometimes. But you are right I do live in a hilly place. Maybe I'll split the difference and go with 4:27 so I squeeze out a little more torque and can still drive at 75 without quite maxing out the tachometer at 3k. Does you know if re gearing is the best option or if there is a place that sells pre-built 3rd members that are cheaper to have installed?

 

[gaz]

Pod,

I don't know what your stock gearing is but I feel 28.5" with 3:73 is perfect as is 32" on 4:10's. Your talking about in between, so I would not chose to go with any but the size combos I've mentioned if possible.

Between a 31" tire with 3:73's or 4:10's, the 4:10 is closer with 31's than 3:73, so that would be my choice to maintain the highest possible fuel economy and performance.

 

[Pod]

Pod,

I don't know what your stock gearing is but I feel 28.5" with 3:73 is perfect as is 32" on 4:10's. Your talking about in between, so I would not chose to go with any but the size combos I've mentioned if possible.

Between a 31" tire with 3:73's or 4:10's, the 4:10 is closer with 31's than 3:73, so that would be my choice to maintain the highest possible fuel economy and performance.

Thanks for the response gaz. I'm pretty sure all the 4x4 models came with 3:73 gears so I assume that's what I have. While I do get pretty good fuel economy with the stock size tires for a 90's truck (20+ mpg), I do find myself downshifting quite a bit on even slight hills sometimes. I think with a bit more torque I wouldn't have to downshift as much which I think would save mpg. I suppose the right way to do it would be to get 4:10 gears and then modify the engine for more power and torque but its more money and I figured since I am having a re gear done anyway I might as well get a little torque out of it as well. That was kind of my thought process behind a bigger ratio than typically recommended.

 

[cbxer55]

My 3,0 Ranger with 26 inch (255/60-15 Cooper Cobra GT) tires and 4.10's, is still pulling hard at 75 mph. Harder than it did with 3.73's. I've had it to 90 so far and it didn't act like it was topped out at all. Don't have a tach, so cannot say for certain. In any event, 90 is as fast as I usually care to go, and it does it without complaint. With 31 inch tires, I fail to see how you'd have a problem.

 

[Pod]

My 3,0 Ranger with 26 inch (255/60-15 Cooper Cobra GT) tires and 4.10's, is still pulling hard at 75 mph. Harder than it did with 3.73's. I've had it to 90 so far and it didn't act like it was topped out at all. Don't have a tach, so cannot say for certain. In any event, 90 is as fast as I usually care to go, and it does it without complaint. With 31 inch tires, I fail to see how you'd have a problem.

Thanks that's really good info actually. I think the only thing is that mathematically I would likely be at 3k rpm at 75 mph with 4:56 gears and 31's so above 75 I would obviously be above 3k rpm. With a race truck like your's that's no problem but I don't think its ideal for fuel economy. Maybe a tune would help with that but then I'm getting into some race car stuff I don't really know much about. Maybe you have something to say on that matter with your experience. Good to think about though.

 

[cbxer55]

Last time I checked, I actually got 20.03 mpg with my set up. And that was mainly around town. And I don't baby it. That's one of the higher mpg readings I've gotten in the 21 years I've owned it.

Race truck? Nah! Daily driver. My Lightning is my "race truck", even though I have never raced it. Mainly, all my vehicles are for my own personal pleasure. I like them to be fun to drive and responsive. The 4.10s with the low profile tires is very responsive. I love it!

I'm just running no muffler, two tips poking out in front of the rear tire Lightning style, MAC cai, with a Spectre stainless steel mesh filter, BBK throttle body, and a JET chip. I do run 93 octane as it tends to ping. Hood is full of holes, including a center scoop that aerates the intake manifold, two small scoops overtop the filter and two Mustang style heat vents. Hellwig front and rear sway bars and Lakewood traction bars. It's a good running 3.0 that runs almost as well as my Mustang with a 4.0 and 3.73's. Mustang soon to have 4.10's.

 

[sgtsandman]

I find 3.73 and 31” tires to be under powered on hills here in the Appalachian Plateau. I would consider 4.10 to be the minimum with 31”.

On the 4.27, I can’t remember if your truck is RWD or 4X4. I considered that ratio but was never able to find a matching set for the front axle. The next closest to it for a 4X4 was 4.56 that had gears for front and back.

 

[Pod]

Last time I checked, I actually got 20.03 mpg with my set up. And that was mainly around town. And I don't baby it. That's one of the higher mpg readings I've gotten in the 21 years I've owned it.

Race truck? Nah! Daily driver. My Lightning is my "race truck", even though I have never raced it. Mainly, all my vehicles are for my own personal pleasure. I like them to be fun to drive and responsive. The 4.10s with the low profile tires is very responsive. I love it!

I'm just running no muffler, two tips poking out in front of the rear tire Lightning style, MAC cai, with a Spectre stainless steel mesh filter, BBK throttle body, and a JET chip. I do run 93 octane as it tends to ping. Hood is full of holes, including a center scoop that aerates the intake manifold, two small scoops overtop the filter and two Mustang style heat vents. Hellwig front and rear sway bars and Lakewood traction bars. It's a good running 3.0 that runs almost as well as my Mustang with a 4.0 and 3.73's. Mustang soon to have 4.10's.

More of a race truck than mine for sure. My performance mods currently consist of a K&N air filter. Hopefully that will change in the future. Thats interesting you get such good gas mileage. Does the JET Chip help you run at higher RPM?

 

[Pod]

I find 3.73 and 31” tires to be under powered on hills here in the Appalachian Plateau. I would consider 4.10 to be the minimum with 31”.

On the 4.27, I can’t remember if your truck is RWD or 4X4. I considered that ratio but was never able to find a matching set for the front axle. The next closest to it for a 4X4 was 4.56 that had gears for front and back.

I agree I can barely make it up hills with my 31's and stock gearing. My truck is 4x4. You're happy with your 4:56 gears on highway and everything as well? The geography around here has the towns pretty spread out and connected by highways so I do a decent amount of highway driving.

Also if you had found 4:27 would you recommend going with those instead?

 

[sgtsandman]

I agree I can barely make it up hills with my 31's and stock gearing. My truck is 4x4. You're happy with your 4:56 gears on highway and everything as well? The geography around here has the towns pretty spread out and connected by highways so I do a decent amount of highway driving.

Also if you had found 4:27 would you recommend going with those instead?

I don’t have 4.56 yet. I still have the stock 3.73. Even with the modifications I have to the truck now, I’m seeing about 19-20 mpg going 70 mph on long trips. I expect the fuel mileage to dip a little bit after the swap. Reality may be different. On a previous Ranger I had that came with 3.45 that I swapped to 4.10 but stayed with the stock 27” tires, the fuel mileage didn’t change. It went from an over worked engine to right at the bottom of the yellow scale on the tires vs gear chart in the tech section.

4.27/4.30 would keep the truck in the best overall mpg/power range going from the stock 29” to 31” if I remember correctly. So, if you were happy with the trucks performance before going to 31” tires, that would be a good match. IF you can find a matching set for the front and rear.

I found the 3.73 gears with the stock tires to be a bit wanting but I do haul heavy loads and tow pretty often. Installing the 31” tires only made that worse and the truck struggles getting up steep hills now. For me, 4.56 is a better match.

If you don’t do a lot of either, 4.27/4.30 may be better but you know what you do with your truck and how it performs better than we would. All we can do is generalize and give you our recommendations based off personal experiences.