much difference between 3.73 & 4.10 ratios?

[racsan]

im considering a re-gear. i currently have 3.73's and run 235-75-15 tires. im not going to change my tire size any but would like a little more power when towing. will 4.10's be enough of a change to be worth all the effort and cost? if i had a 2wd id just go for it, but i have 2 differentials to deal with. i think 4.56 would be way too deep a ratio, granted i could pull a dead bulldozer if i could get the traction, but then it would probly be floating the valves at 60 mph. i know there was a hugh difference in the farm pickups we had, one had 3.73's and the other had 4.10's but both trucks had different motors and transmissions, so its hardly a fair comparison. if i do re-gear im thinking of putting in a lock-rite or detroit locker in the rear. i want to leave the front a open diff. maybe the bottom line is that i need to upgrade to a bronco or F150. my trailer isnt all that big or heavy (6x10, 1,000 empty, 3,000 gvwr) but it is tall and even though it has a V-nose front, its like deploying a drag cute when above 45 mph. at 55 im getting about 10-12 mpg with only 500 pounds in the trailer. in fact fuel milage doesnt seem to change with trailer load, empty or 1/2 full of oak firewood, it still drinks fuel like a big-block. so would 4.10's be enough of a change to do me any good?

 

[4x4junkie]

It's not a huge change, but it should be noticeable.

 

[Ranger Sport Honduras]

sorry to jack, according to the gear calculator 4.10 work fine with 33" tires if the stock ratio was 3.73, but it still be good for 31" tires? with a 2.5 engine?

 

[Flash Gordan]

If you go to 4.10's it'll just drink fuel that much more. Either stay with the 3.73's or if you go with the 4.10's, be sure to get a taller tire to compensate.

 

[Ranger Sport Honduras]

my current ratio or effective ratio is 3.41
the hi ratio alternative is 3.72, my 3.73 works fine there
the new ratio is 4.08
the lo ratio is 4.45
i assume that a 4.10 will give back the power it lost for bigger tires?
if i put 31" tires my effective ratio is 3.3
hi:3.81
new:4.22
lo:4.6

so whats the diff between the three options?

 

[Ranger Sport Honduras]

i dont know what u meant lol sorry, seems like im gonna keep the 3.73 then
thanks for the input and sorry for jacking

 

[Spowerback]

cheak site http://www.southsideoffroadcustoms.com/Gears.html or http://www.therangerstation.com/tech_library/Metric_To_Inch_Tires.html

 

[Ranger Sport Honduras]

thanks man!
according to the table im ok with the gearing i have and the tire size
i saw that chart the other day, thats the amount of RPM to achieve 60mph on fourth gear iirc, with 30" and 4.10 it would be almost at 3k rpm thats not too good for fuel economy i must say

 

[Ranger44]

If you go to 4.10's it'll just drink fuel that much more. Either stay with the 3.73's or if you go with the 4.10's, be sure to get a taller tire to compensate.

Say what?

Small engines, such as the 4L, 3L, etc, actually appreciate a little help. In many cases, and even my own, many have recorded better mileage with lower gearing.

Now with a larger V8 or I6, it's different.

 

[martin]

From what you say in your original post it sounds like your main issue is aerodynamic not weight. As long as you are around the peak torque figure at highway speeds I don't think a gear change would be much help. A cheap way to find out would be to find a friend who has some smaller diameter tyres and see if it helps with them on. I suspect it will help with acceleration at lower speeds but as soon as you get up to where drag starts taking its toll you will be back to square one.

 

[Captain Ledd]

To the OP:

4.10's would make a difference, not a particularly huge one, but you will notice it.

As for improving mileage, it would seem likely to increase. Moving up the horsepower curve up a little bit allowing it to work better at speed. BUT if your driving faster than you are currently, fuel economy will probably be the same or even less. So fuel economy for the same max MPH your going now (but with 4.10's), it should increase.

Hmm.. that's a little awkward to read to me, I hope I don't need to clarify a little better? lol

As for 4wd, the T-case will not like the 2 different ratios. However, it will still definitely get you out of a snowy parking space/driveway/etc., but I'd use it pretty damn sparingly.

 

[JimJa1943]

Racsan, My experience may help with your decision. 2yrs ago I bought a used '05 4x4 4-door w/4.0, L/S & 5sp as a work truck at a cabin I own in Wyoming. Tires are stock 16" (29" diameter). Shortly after purchase I switched the 4.10s for 3.73s. This was done because most of the MILES are at freeway speeds and I previously had good luck with a 4.0 Explorer with 3.73s.

Adding to the mix is the fact the cabin is at 7,500' so right off the bat there is a ~20% power loss compared to sea level. Although most of the miles are on the freeway, most of the TIME is in the area around the cabin.

I am going to switch the gears back to the 4.10s. With the 5sp it just doesn't work very well for me with the 3.73s. First gear is too low, and 2nd is too high for the gravel roads around the cabin. Since most of the TIME is there, I'll just have to slow down a little on the freeway.

The intention is to sell the existing 3.73 rear axle, buy an open axle w/4.10 and install a locker. I'm just trying to get it right for my driving style. If it had an automatic I'd leave in the 3.73s. MPG is a little better w/the 3.73s at 23-24 on the highway and I know that will suffer a little with the 4.10s, but the drivability is much better with the 4.10s.

I might also leave in the 3.73s if most of my driving was at a lower altitude and/or in an urban environment. I've towed ~ 1,100 lbs with the 3.73s and it's fine for that, even at the higher altitude.

 

[racsan]

i think what im going to do is put on a used set of tires in the 215-75-15 size, that should be darn close to what 4.10 gearing would be like, and see what happens. i think the bottom line is its just too much wind resistance to overcome with the horsepower ive got. in town its just fine, the truck by itself is just fine. ive thought of making a "wing" to go on the cap to deflect air, kind of like you see on over the road trucks. or if i could find a different cap that is higher at the back than mine is now. thanks for all your replies.

 

[dla]

I just went through the same process. I have the 2.3 and 5spd. Stock was 3.73. As soon as I went to a LT235R15 tire (to get a 6ply to avoid rock flats), the increase in tire diameter (not even an inch) killed my power. 5th gear was all but useless. I chose to swap in a 96 Explorer 8.8 and regear to 4.30. Why? 4.10 wasn't enough and 4.56 seemed too much unless I want to go to larger tires (which I don't). Ford Motive 4.30 gear sets seem to be popular in Mustangs and were on sale - ~$100 less than 4.56. Going to the 8.8 gave me lots of gear options and an axle bearing strength increase - I was wearing out 7.5" axle bearings in 40K miles - mostly highway and a little wood hauling.

 

[AllanD]

I run 235's in a 5sp 4x4 supercab with 4.10's.

Frankly the gears are "too much".

Basically it limits highway speed too much when NOT towing...
IF I want to get reasonable fuel mileage.

I CAN get 21-ish with my 4.0 if I keep to no more than 60-65.

6065 don't make it for me when driving across Iowa and Nebraska
to visit my brother in wyoming.

On another note I got 16mpg comming back from South Bend Indiana
while TOWING another complete Ranger on a tow dolly.

I was NOT restricting myself to 65mph max.

I crossed most of Indiana and Ohio at 70mph.

There wren't many times I needed to shift out of 5th
let alone 4th...

So I've gotta ask what are you towing that you need/want/expect
to get "more" from your 4.0 with 4.10's?



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