Gear Ratios

[knoxswift]

And this is where we part ways... there's more to mileage than gear ratio. People adding 1k+ pounds to the truck, rolling resistance, height, etc... making a blanket statement that gearing is the impact on mileage is... well... not correct.

Agreed but good choice of gears can help correct the issue.

 

[knoxswift]

Nomenclature in this thread seems to be sideways too.

Tall gears, AKA high gears = low numerical gearing. Ex: 3.73:1 is taller / higher than 4.56:1
Short gears, AKA low gears = high numerical gearing. Ex: 4.56:1 is shorter / lower than 3.73:1

I agree with everything Dave said. With my manual (Gen II) Tacoma), I have found that 4:56 is the best option. To operate well with bigger tires, more weight, and higher profile, you need to operate higher on the power curve, because the truck requires it. It is not enough to simply match or approximate stock gearing. As it is, I have to shift to 5th on any moderate grade. 6th gear will not sustain 65-70 highway speed, except on mostly flat ground. If I had higher gears, I would virtually never use 6th gear unless I was going down hill. You can get gearing that drops your RPM to 2000, but if 2000 won't move the truck, then you end up down a gear and you have gained nothing. Choosing higher gears also takes a bite out of the truck's crawl ability, which isn't great to begin with. 4.30:1 would be a better choice for 235/85-16, which I ran for a long time. It is both a shorter and lighter tire. All of the modifications that we make to these trucks to make them more capable, also impact fuel economy. There is really no way around it.

And that's the reason for my post. I have had very successful results with 4.30s. For an all around daily driver and off road capability in the 4.0/2nd Gen/33s (17s)/MT

 

[Clutch]

you realize you're preaching not modifying to a group of people on a forum dedicated to modifying their rigs... right?

Well...of course!

Do you think it is worth the time, money, and effort for such minimal gains? Is it about performance...or is really about looks?

Recently went down a size and a less aggressive tire, amazingly they took to the same camp spot that the other tires did. OMG! And gained 2-3 mpg's in the process.

Probably the best "un-mod" I have done...should of done it years ago. Best part it is...only paid 300 bucks too. While I normally spend $900ish on tires.

 

[bkg]

Well...of course!

Do you think it is worth the time, money, and effort for such minimal gains? Is it about performance...or is really about looks?

Recently went down a size and a less aggressive tire, amazingly they took to the same camp spot that the other tires did. OMG! And gained 2-3 mpg's in the process.

Probably the best "un-mod" I have done...should of done it years ago. Best part it is...only paid 300 bucks too. While I normally spend $900ish on tires.

You feeling okay? Perhaps I can I interest you in a knitting group? Maybe crochet?

EDIT: the reality is that most people can make it to most of their camping spots with a 1990 Honda Civic... 4wd is really only an expensive option... Except for my driveway - that's 4wd only.

 

[Clutch]

You feeling okay? Perhaps I can I interest you in a knitting group? Maybe crochet?

I do need to sew a tear in my Klim jersey that tore open over the weekend while dirt biking...

 

[KJP]

Best I can say is don't rely solely on the numbers you calculate, but from folks who run certain gear and tire combo's. Looking directly in the mirror on this one... I have a 2nd gen Taco with AT and run 265's. The "math" said 4.10's would be perfect, and after a couple of thousand bucks I found out the math was not that good. I now have changed to 4.56 and feel with the auto tranny it's pretty well right in the ball park - I am just around 2200 rpm at 60, yet can still do 80 without the engine sounding like it's overbuzzing. I was debating going to a 33, but based on my experience, I should have 4.88's for that, although I'm sure my 4.56's would do just "OK". Anyone want to buy a complete set of diffs with 4.10 gears LOL.

Did the same thing on my Jeep when I went to 35's, and didn't learn from that one either haha.

 

[DaveInDenver]

Seems like an awful lot of fuss for minuscule off-pavement performance.

You can put a truck with 31's anywhere one with 33's can go...

If it doesn't matter then why not go back to 225/75R15 Dunlops Toyota used to put on the trucks stock? BTW, that's another point that needs to be made about 4.10 stock gearings. Those were matched with those tiny 28" tires.

 

[Clutch]

If it doesn't matter then why not go back to 225/75R15 Dunlops Toyota used to put on the trucks stock? BTW, that's another point that needs to be made about 4.10 stock gearings. Those were matched with those tiny 28" tires.

Sure why not.

No one has yet to answer the question. Is it really worth all the fuss for such a minuscule gain? Are you really going to get back in that much further? Is it truly about performance, or is it it about looking cool to others?

I normally run 32's...the truck pulls them just fine. Now dropping to 31's...I can't tell the difference Only that they are quieter and returning a touch better gas mileage.

 

[DaveInDenver]

This sounds a lot something I've heard before. What was that? Oh yeah, 29'ers for the win! Clutch, the resident 26x1.9 curmudgeon.

I'll just throw out a few terms. Angle of attack, dynamic and static load radius, contact patch. Diameter and width are not trivial, these things do make a difference. We must obey the laws of physics in this house.

 

[Clutch]

This sounds a lot something I've heard before. What was that? Oh yeah, 29'ers for the win! Clutch, the resident 26x1.9 curmudgeon.

I'll just throw out a few terms. Angle of attack, dynamic and static load radius, contact patch. Diameter and width are not trivial, these things do make a difference. We must obey the laws of physics in this house.

27.5 is all the rage now...doncha know. (and I like 26X2.1's btw... ) Can't have those 650b wheels on the shelf collecting dust. Lemme see...hmmmm... who can we sell all these roadie rims that no one wants anymore...oooh I know! Hey mountain bikers...ya know those 29ers that are so hawt right now...yeah well, those are yesterday's news.


And the percentage of increased capability going from 31's to 33's is.....?

I have run 33's on my truck before...I couldn't tell a difference. Sure did look cool though. Tried them out and was comptimplating on a regear to be able to run them...couldn't see a massive advantage to go through all the trouble. So I sold them and went back to 32's. Even had a chance to do a re-gear last year when the 3rd member blew up...but decided to stay stock.

The 31's on there now, was a fluke...I just wanted the rims, could care less about the tires. But I figured I would run them bald and replace them with the size I normally run...but I am liking them.

 

[tacollie]

650br0 for the win! 27.high5!

1gr in the 79 series is geared to a 4.10 with a 5 speed MT on 265/70r16. 5th gear is .88. I would like that set up but it would drink the gas doing 80mph.

Obviously off road lower gearing is nice but pulling grades in the mountains is better to. I really liked my 07 mt in the mountains.

@Clutch lighter smaller tires are underrated. I ran p-rated for my last set in a bigger size than I have now. Truck rode and drove better and I got better milage. I also got to use my plug lot a lot! Now I have e-rated in the same tread. Ride is a hair harsher and milage has gone down but I've had zero flats.

 

[TernOverland]

The amount of ground clearance you need is dependent on the trails you run. It is true that many people way over estimate what they need, and sacrifice off camber stability and other virtues in the trade. That said, gaining a couple of inches over stock definitely does make a difference in the trails you can run without trouble. A couple of weeks ago I drove 45 miles over a boulder strewn road that took me over 7 hours of driving. I was constantly picking my line to avoid hammering the underside, and that is with 33's, 3" of suspension lift, and 4:56 gears. Could I have done that in a stock truck? Probably, but there would have been damage, and it would have taken twice as long to cover the same route. As it was, the 7 hour+ drive was exhausting. Without the cushioning effect of the bigger tires aired down to 14PSI, I would have been beaten to hell.

The article cited earlier is a good one, worth reading, but it is predicated on a truck saddled with weight well over its GVWR. The trails that truck can take on are already limited. The best strategy there is to go for traction enhancing devices.

 

[Clutch]

650br0 for the win! 27.high5!

LOL!

The bicycle industry...always dreaming up "new" ******** to sell you...I see elliptical chainrings are back....that and purple ano...just you wait(!) bar ends are coming back yo!

Did I just see toe clips, and a Yeti Ultimate inspired frame....wuuuut!?

This thing kinda checks all the boxes for what is "hip and in" right now...gotta say, I kinda dig it...am a sucker for vintage tho'.

Obviously off road lower gearing is nice but pulling grades in the mountains is better to. I really liked my 07 mt in the mountains.

@Clutch lighter smaller tires are underrated. I ran p-rated for my last set in a bigger size than I have now. Truck rode and drove better and I got better milage. I also got to use my plug lot a lot! Now I have e-rated in the same tread. Ride is a hair harsher and milage has gone down but I've had zero flats.

Never really had a need for P-Rated street tires only living 2.5 miles from work...(used to ride my bicycle most of the time anyways) now with a 60-90 mile round trip commute. Wow what a difference! Loving the quietness. Do have an extra set of rims with AT's on them for muddy spring camping. May put a set of MT's on those rims. The mud is something else here...it is like brick mortar. Damn near need to run chains in the spring.

It never fails, you'll be back some mildly gnarly road thinking you're a ************...with your lift, knobbie tires and winch bumper...then there is a rancher with a 2WD truck on street treads. Or worse, some worn out looking meth head dude in a Honda Civic...

The amount of ground clearance you need is dependent on the trails you run. It is true that many people way over estimate what they need, and sacrifice off camber stability and other virtues in the trade. That said, gaining a couple of inches over stock definitely does make a difference in the trails you can run without trouble.

Have a 2.5-3" lift on the truck already....don't really like running a lift, however kept on breaking the stock stuff. It was the only option that, or get a 3/4-1 Ton. Ran 33's for a couple months just to "see" what all the fuss was about...ran the same trails I normally do, which had a bunch of rock ledges, drop offs, and such...couldn't tell the difference. I see you're from AZ. This was the Reddington Pass/Chiva Falls area outside of Tucson, and the Florence/Coke Ovens area. The 32's (31.5) tall are 11.5 (9.3) wide...the 33's (32.5) were 10.5 (8.5) wide. So the contact patch is virtually the same....and only gain an inch of clearance. So you guys thinking that there is a massive gain in capability...must be more sensitive than me. Cause I couldn't tell the difference. Only thing that was bit different was the truck was ever so slightly sluggish when unloaded. (but in low range didn't notice) Which I feared being completely loaded down it would suffer climbing mountain passes on the hwy. Is just about $2500 OTD with tires to gain a measly inch of clearance. Conclusion... not worth the time, money, and effort for minimal off-pavement capability increase...and would give up some mpg's on the HWY. Which the truck already gets poor fuel economy for what it is.

Now, buddy's truck with a solid axle sitting on 35's...that is almost night and day better off-road. But we constantly broke parts in that truck...

We had engineer guys in our dirt bike club that would argue over carbon content in tires and gearing...me I could care less, and was faster than both of them. They would be **********' around trying to crawl up a rock face with their trials tires...and I am like just hit it at speed and make a jump out of it. Braaaaap!

 

[KJP]

Must say I'm enjoying this thread - usually just a reader and not a poster, but can't resist. I think we have to be clear on our intentions here... if you are an average overlander (based on what I see on the pages of this site) then it's true, you rarely are using the capability of a stock vehicle, and get by with stock tires and a good winch (and let's not forget good skid plates). I'm going down this route staying with the 265's - yes, slightly larger than stock and did I really need them - no, but I like the look and wanted ARB's anyway so a gear change was sensible. However, don't hate but I have a long history with rockcrawling and Jeeps, and the extra ground clearance a 1/2 inch makes when rockcrawling may mean the difference between failure and success. So simply look at the trails you intend to drive, consider what you want your vehicle to look like, and find a balance between the two. I have 35's on my Jeep, and am considering 37's - cause I need the clearance. I have 265's on my Taco, and would like 33's for the looks, but realize I wouldn't notice the difference in what I use it for. But note there is an advantage to spending money for looks... you get the image you want and you spend money which keeps businesses running which gets more products on the shelves and the economy keeps going - good for all of us LOL.

 

[KJP]

Edit - just realized I strayed from the conversation on gear ratios - whoops. So I have to say something about ratios or I'm breaking the rules - ummm stock is good if you're stock, 4.56 for 32 inch tires, 4.88 for 33 inch tires - for AT tranny. Your results may vary.