4.88 Re-gear on horizon. Now looking at taller tire options.

[Road Bull]

Sup all! I am pretty close to pulling the trigger on a 4.88 re-gear and rear ARB locker. If you were doing a 4.88 re-gear, would you try something larger than 285/75/16's?

I know that this question is dependent on how you use your 4Runner.

I am currently running BFG 285/75/16 tires on SCS F5's with 3.5 BS with 3" lift and no BL.

I like to try to future proof my vehicle a bit by leaving room for options with my upgrades. Part of why I picked the 3.5 BS SCS F5's was due to them being a suggested BS to clear 315/75/16's easier without having to run spacers, should I ever want to do so.

I had been doing alright with stock gears and the 285's, but that combo leaves you wanting more get up and go when you are heading up the pass. The 4.88's seem to fit a wider range of tire sizes while not punishing you for trying to push highway speeds on the regular. This is my DD.

Now the options that I am considering: Using Cooper ST Maxx for reference.

255/85/16 = 32.8" (not really any taller than my 285's)
315/75/16 = 34.45" (time to tub it up)
285/75/16 = 32.91" (seems like a vanilla route after a re-gear, lol.) :shrug:

or... Join the 17" wheel evil empire. lol.
295/70/17 = 33.23"
285/75/17 = 34.06"

I had been planning on taking advantage of the October Discount Tire Direct eBay sale to try out a new tire. This would be a great time to try something different out. In some ways, the 315/75/16's are a more common size and generally run a bit cheaper compared to 17" options or less popular sizing.

I do a fair amount of highway driving. For offroad, I have been getting out a bit more this year and having fun on some more challenging trails with more technical rocky terrain, some snow wheeling,

Do you think jumping up to 315/75/16's is a better route to go if you wanted a taller tire? The 285/75/17 seems like a cool option on paper. There are not a lot of 34" options out there. I know there are a few that run this size, but I don't hear all that much about them. I would have to try to figure out a new wheel option for the 17" size that had optimum BS. There seems to be few options that offer similar specs to what I am currently running.

Thanks for reading.:snacker:

 

[BrianSD_42]

This is strictly my opinion so here goes. Stick with 285s and don’t try to turn your DD into an offroad beast.

I am very happy with my 285s. Instead of spending $2k on gears and install plus another $1k on tires again ... buy a brand new OEM SuperCharger for $2700 and get it installed for a few hundred. That is the same $3k and a WAY better use case $/performance vs a re-gear, assuming you stick with 285s.

Also on a side note have you considered getting a separate DD and keeping the 4Runner for trips or camping? That too is a great use of cash that will pay off in mulptles over the next several years. Every mile driven on your rig is money burned and a new 5th gen is $45K (wow!).

 

[Road Bull]

[MENTION=65101]BrianSD_42[/MENTION] Thanks for the response. I know the questions that I asked seems like I am on a run away spending train to beast mode, but here's my thinking.

This started by wanting to add a rear locker. I already have the compressor. The more I researched, the more opting for better gearing at the time made sense. It IS more expensive to do both, and partly why it hasn't happened up till now. But, I figure that it would be better for the vehicle overall, even if I stick with the same 285 tires.

The tire options opening up is a byproduct of my decision to add the locker. As far as tires go, a change is optional, based on needs, wants, and finding "Goldilocks" version of new tire for me.

I think at some point I might add another vehicle to my life again, but I will most likely be rolling a single vehicle for the foreseeable future. I don't want to lock in another guaranteed payment in my life at the moment. I like the supercharger idea, and I would pursue that a bit more if I didn't already want to add the locker. I just figured, for a bit more effort and money, I can kill two birds with one stone. LOL.

 

[RockyrT4R]

I run 35s on 4.30s (elocker specific gearing) and I daily drive mine. I will be going to 5.29s because I tow a lot and would like the extra torque. 35s are quite streetable if you get nice tires.

 

[BrianSD_42]

This is just me, maybe some would consider this traitorous but driving my truck I'd rather have a new OEM Supercharger (I don't have an SC) over a rear locker which I do have.

Of the hundreds of hours I've spent in 4WD by now I only needed to use my locker less than 5 times. I could see it as a major gain if you do a lot of deep snow Wheeling or something. I hit up a lot more medium to difficult 5,6 rated trails than 7,8,9 hard thrasher trails. Even in Moab I only needed the locker once.

Vs a SC which I would use everyday!!!!!!

Sorry for the derailing of the thread lol.

 

[Road Bull]

You didn't derail the thread man. You make a valid point about the supercharger. That is another mod that you get a lot of bang for your buck. It would be a lot more attractive if I already had an e-locker. I always keep my eye out for used supercharger, but they are few and far between. I could see buying a new one stone some point down the road.

Does anyone here with a 3rd gen have 285/75/17's? It don't see it referenced here too much. Perhaps it is not all that popular because it is close to 35 and 33" wheels...

 

[thecole1098]

Personally if it was me I would stick with the 33s if you have been fine clearance wise in the trails, especially if you are going to be DD it still.

As for lockers or not, I first hand experienced what it was like to own a vehicle with at least one locker (my 96) and to go to one that is open/open (98 XJ). For the type of terrain I ride with my group, which is typically pretty technical/extreme crawling, I can say that I looked like a fool in the Jeep due to me always spinning and loosing any foward momentum I had when one of my tires got to a bad spot. Not only was I embarrassed because my old 4runenr that was behind me most of it got up stuff I struggled on no problem, but also because I held up the rest of the group quite a bit. So needless to say, I’m dual l locked now (lunchbox lockers) and am ready for my next outing lol

 

[Tyler James Inc]

I completely disagree with Brian; I would do gears and locker before a S/C. Also, tire height varies GREATLY from one manufacturer to the next. On top of that, did you see the re-gear thread where a couple of us did a couple tanks of fuel where we didn't shift into our highest gear for the whole tank? Fuel mileage didn't suffer at all. I drove 70+ mph on a daily basis(20 miles at a time) in 4th gear on 315/70R17 KO2 and was getting the same 17-18MPG I get when using 5th gear on the highway.
I would probably even go 5.29, to be honest.
On to tire heights...
My 315/70R17 KO2 were only 33.5" tall BRAND NEW. I measured them on the truck, as well as off- same height either way @ 40PSI. The website says they're 34.4" tall. That's BS. A couple weeks back, I asked a BFG rep about their new KM3, and asked if they'll be running super small like their other tires do. They said "our tires are measured free-standing, NOT mounted on a wheel. And yes, the KM3 sizing will be the same." Hm, okay, fine. So if I want a 35" BFG, I'll have to buy 37's.
Fast-forward to last weekend- I picked up a brand new 37x12.5x17 for a buddy. While I had it, I measured the un-mounted, free-standing height of the 37".
The results were exactly what I expected-

Just a hair over 35" even. Not even 35.25". That's a brand new 37" KO2.
My point is- when talking tire heights- just know the sizes can vary GREATLY between manufacturers.
I put 20k miles on the 315's in my '97 auto, and 22k miles on the same 315's now in my '01 manual- in either rig, the tires made no noticeable change in power from 265/70R16 highway Coopers. I'm not sure if the gears would make much noticeable power difference, but I bet you would see better fuel economy. I know some would disagree, but I've done many experiments with my '97 and '01 both, and both got better fuel mileage at higher RPM.
Shit, I didn't even answer your question. I also think the 285/75R17 is a cool tire size. My vote goes to 17's and 285/75's. For what it's worth, I run 17x9" wheels with a 5" backspace in my 315/70R17's. The wider wheel makes the sidewall flatter, making higher backspace wheels possible. Having the higher BS is good for keeping minimal scrub radius for fitting taller tires. I kiss my UCA at full droop, but hasn't been an issue at all for 42k miles.

 

[SupaSupra]

I run 35x12.50s with 3.73s. Is it retarded? Sure, but the only adverse effect I have is acceleration and fuel economy and I didn't buy my truck for either. I daily mine and it rides just as good as it did with 33s, that being said I do wish I had 4.88s.

 

[theesotericone]

I'd rather have a new OEM Supercharger (I don't have an SC) over a rear locker which I do have.

I hit up a lot more medium to difficult 5,6 rated trails than 7,8,9 hard thrasher trails. Even in Moab I only needed the locker once.

I completely disagree with Brian;
I would probably even go 5.29, to be honest.

OK [MENTION=119532]Road Bull[/MENTION] there's a lot of way's to look at your question. I quoted two very distinct ways.

Gears are low end torque. SC's are high end power. What would you rather have?

That is going to come down to how you use your rig. Only you can make that decision. With that said, here's my take on your situation.

Go 5.29's.

I've run a trail with Brian. He's oem stock gears and had to lock the rear. Then he had to gun it to make the uphill. I locked my rear and casually drove the same section. It wasn't skill that determined the speed, or a locker, it was gearing. I have the low end torque that he doesn't.

I'd be happy to hook my rig up to anybody that has a similar tire size and a SC. Then we both put it in 4lo. Then we have the tug of war. I'll win every time. It's torque not power that keeps you going in harder 4x situations.

If we did the same test for a 1/4 mile in 2Hi the SC would win every time.

So make the smart choice for yourself. Decide whether you want a wheeling rig or a street rig. Then spend your cash.

As far as having a worthy hard trial rig that's also streetable? Come down any time and drive my rig. It's gonna surprise you when a dual cased, fully armored rig on 33's drive down the highway at 75 MPH with no vibrations. You can have it both ways. You just need to put in the time and money.

 

[theesotericone]

On to tire heights...
My 315/70R17 KO2 were only 33.5" tall BRAND NEW. I measured them on the truck, as well as off- same height either way @ 40PSI. The website says they're 34.4" tall. That's BS.

Hey Tyler,

I wanted to address this in a single post. You hit the proverbial nail on the head. Most guys running 33's are on 32's. Most guys on 35's are on 34's. The tire industry is pretty frikkin lax in having an actual standard.

One thing that a lot of people don't take into consideration is lower air pressure. Lower a true 33 and lower a true 35 to 12PSI. Assuming the rim diameter is the same the ground clearance is also within 1.4" of the same. The big difference is the 35 now has a lot more sidewall to get cut.

This is the single reason that I run true 33's. I'm not sacrificing that much clearance when aired down. I also have less circumference to spin off the line in the DD situation.

Ideally, I'd have 33's for DD and 37's for wheeling. Making that happen without a body lift is gonna be a biatch. I hate body lifts and I'd really like 37's so we'll see what happens. lol

 

[Road Bull]

[MENTION=143526]theesotericone[/MENTION]
Oh, I am going the gear route for sure. I don't have anything but drool, respect, and desire for a supercharger, but that's not even on my radar at the moment. My question was geared, (no pun intended), more toward the idea that I will be re-gearing. And the re-gearing will be getting done MAINLY because I want a rear locker. I see lockers as a true capability multiplier. I figure that if I am going to go through all the trouble of adding a locker, that it would be a great time to change the gears up to enhance my capabilities, put me closer to factory power-bands to take some strain off the engine, and enhance some capabilities offroad.

From what I had read for the most part, people seem to think that 4.88 gearing is most ideal for 33-35" tire options. (maybe more so if DD). In fact ECGS did suggest 4.88 being "stronger" without much elaboration. There were a few people advocating for 5.29. One of my concerns is DD. I just wonder if 5.29 would put me in much higher RPM's for ~70 mph daily driving on highway. I just went out and got a quick eyeball measurement with a tape measure. It would seem that 285/75/16 BFG KO2's measure to about 32.5" or thereabouts. I don't really travel any faster than, let's say 75 mph. :spy: Where would that put me RPM wise with 5.29? I suppose that is a bit of a loaded question not knowing what size tire I will end up with. I was planning on at least trying a 255/85/16 if nothing else, but that also seems to be a short 33" as well. If I wanted to add any real height, it would seem that I would have to go with a 315/75/16, or jump into 17" wheel options.

I mean, I would have a bit of time to figure out what I want to do. I would most likely be looking to swap out tires during the discount tire direct ebay sale in October. If things go quickly, I might get this done later this month or early next. What all needs to be done to accommodate 35" tires beyond tub front and swap out windshield washer fluid resi? I already have SS extended rear bump stops. Would I have to mod the rear wells or 4X Innovations rear bumper to make them work?

I don't HAVE to jump up a tire size. I just figured that if I was planning to already, AND I had optimal gearing, it would be a good time to try something different. Would 5.29's be too much for your average 33" tire?
[MENTION=116470]Tyler James Inc[/MENTION]
Thanks for sharing all those measurements. There seems to be little truth in advertising when it comes to "actual" tire size. I know BFG seems to run short across the board, but man... that is really short. So, 35's in name only. I mean.. it might make them easier to fit, but still. And I like the way a MT looks, but I would also be concerned that they perform poorly on early morning, wet, crowded with distracted idiots laden I-5 on my way to work. That, and I keep reading that MT's tend to chunk up on gravel and rock a bit more than a hybrid MT / AT. A lot of people around here run Cooper STT Pros with success. But I also hear widely different reports on how long they last when also performing DD duties. That's why I was leaning more towards a Cooper ST Maxx. They seem to run a bit closer to true size, within ~.5" LOL.
[MENTION=136902]thecole1098[/MENTION]
I hear ya. I would say that, if you have the time and option to approach a difficult obstacle from alternate lines, you might find one that works for open/open. Also, experience helps. But sometimes, it's shit soup or shit sandwich. Some obstacles on our last trail ride really required you to take them "one way". There was no room for alternate approach. Running open/open, it leaves you few options. I made it work, but I figure with a locker and lower gears, I will have more options with difficult sections, and will be able to run them in a more controlled approach.

 

[rideexileex]

For a DD, 5.29’s are way too high.

I have 4.88’s, SC, and 35’s, and it’s a dedicated trail / camping rig. 4.88’s are for the tires while in high range - it might make slight, again slight, difference while wheeling sure, but I think money would be better spent with a second transfer case for the best of both worlds. My favorite combo for a DD car was 4.10’s, 33’s, and a supercharger - it had speed, MPG’s while cruising, and gearing was still fine off-road for the occasional trail compared to frequent city / highway.

There is a 6% difference between 33 and 31 inch tires... not all that big of a deal and the SC more than compensates. If you do rehear, you should consider going full retard and replace the front carrier with an ARB locker too.

BTW... gears don’t “add torque”, they add gearing, effectively slowing things down and adding control by keeping static friction... there’s some fishy internet engineering above. More sidewall? Duh? Don’t even know what to say to that.

 

[BrianSD_42]

I've run a trail with Brian. He's oem stock gears and had to lock the rear. Then he had to gun it to make the uphill. I locked my rear and casually drove the same section. It wasn't skill that determined the speed, or a locker, it was gearing. I have the low end torque that he doesn't.

That hill was a lot of fun and the working locker definitely provided extra confidence!

To be fair I didn’t feel like I was short on torque at all while in 4lo but I have no idea how it compares to a regear. The locker definitely helped as an easy button.

Definitely depends on what trails Road Bull wants to run and how often.

 

[MattJakobs]

I go through a very similar debate every time I go wheeling or on a long drive. I'm at 8/32nds on my tires so while I'm not in dire need for new tires, the time is approaching.

The conclusion I've come to for myself is 4.88s and 285/75/17.

If you plan on regearing, I definitely would recommend stepping your tire size up. I have a buddy running the exact same wheel and tire combo (285/75/16 ST Maxx with 16x8 3.5BS SCS F5s) as you, only he's got 4.88s. On the highway, you can notice his gearing is off. High revs and lower than usual MPGs are to be expected. But off road, he has tons of low range power and it doesn't go unnoticed. Like you, it is his DD but he does plan on making the jump to a 285/75/17 once his tires wear out.

I like the 285/75/17 option because 35s come too wide for my liking. I don't need anything as tall as a 35, and the width of a 315 really doesn't fancy me.
A 285/75/17, or 34, are the exact same width as our 285/75/16s, just an inch taller. I'll be going to F&R lockers and doing gears with it. To me, it's smarter to go to 4.88s rather than going with a stock gearing (4.10s or 4.30s) or making the smallest of steps to 4.56s.

While it is harder to find a 3.5BS 17" wheel (though I believe SCS is going to start making them in the Ray 10s), they're out there. When my tires wear out, I'll be making the jump to 17s with a 4.30BS and 285/75/17. I'm hoping 17s with 4.30BS with a taller tire should have about the same forgiveness as my 16s with 4.5BS that I have right now. Clearing those weren't hard to do at all and I don't think I'll have to do much more, if any, clearance work.

To me, a SC is pointless. I've never had the desire to get one for the added parts, higher fuel costs, and well-I drive a 5,000lb+ 4Runner. It's not supposed to be fast. I often drive as efficiently as possible to get every additional MPG that's there and a SC wouldn't help. Gears/Lockers are a far more useful purchase in my opinion because I have come into places that I've needed them.

I'd also consider adding a front locker. While it may be expensive and excessive right now, having a locker would bring my confidence level up off road and have me trying harder and harder lines. Better to buy once, cry once for me in this situation.

 

[Bijan]

We seem to have a similar situation, build, and desires.
I have full armor, 285/75/16s, SCS F5 3.5" BS, supercharger, daily driver, weekend rock crawler.
I have been debating a 2" BL + 315s and re-gearing

I have finally decided to lock both ends with ARB air lockers, but cannot decide if re-gearing is worth it. I calculated the stock tire size and new tire size by stock gear ratio and only found a 3% increase to swap to 4.30 gear ratio. To me, 3% is not worth it - especially if I don't plan on going with bigger tires.

I want the best ALL around performance....not biased toward daily driving or rock crawling. Right in the middle. So....any suggestions would be cool.

I drive pretty often at 60mph+ on highways, and dont want it to be screaming.

 

[Bijan]

So if you want as close to factory gear ratios.... the equation is

NEW TIRE SIZE (in inches) multiplied by FACTORY GEAR RATIO (4.1) divided by FACTORY TIRE SIZE (in inches)

 

[psraff]

So many good points on here, and it makes you change your mind every two seconds (at least I did).

So you don't have a locker so your current gears are 4.10 right? I was locked so I had 4.30 gears and with tires (255/85-16) and weight, I could really feel the lag at highway speeds going up and through the mountains. When I asked about gearing, 90% told me to upgrade to 5.29 (because I was thinking of 35s). I'm glad I did. Even as a daily driver, I don't think 5.29 gears are too much (FOR ME). Almost all roads up here aren't over 55 MPH. Take that into account. I've read other threads where people down in the Lower 48 also love their 5.29 gears on their DD.

I'll be honest, changing to 5.29 gears, even though I felt the difference, after the first week of running around town with them, I had to lift up my back end and measure my gears to make sure they were truly 5.29s. I kind of expected more low end feel to them. When people said I wouldn't feel a difference between 4.30 to 4.88, I believe them!

Now this thread is talking about tires, not gears... So, I for one LOVED my Toyo MT 255/85-16 tires. Toyo tires are heavy. In some cases 6-8 lbs more then other tires. I'm a fan of narrow tires. I think I always will be. It's sad, there's isn't many options for them.

Only draw back is you said you did some snow 4Wheeling. A narrow tire may not be your best choice if you go off road in the snow.

We've talked about 34" tires before an yes, I'm pretty sure the only way to go would be a 17" wheel so you have the choices of the tire. I would love to hear from people who have them and how they look.

 

[theesotericone]

For a DD, 5.29’s are way too high.

BTW... gears don’t “add torque”, they add gearing, effectively slowing things down and adding control by keeping static friction... there’s some fishy internet engineering above. More sidewall? Duh? Don’t even know what to say to that.

I DD drive my rig with 5.29's and 295/70/17's just fine. Your entitled to your opinion but it's just an opinion. Not fact.

Gears are a multiplier of torque. Going to a numerically higher gear ratio increases your output torque. There's some not so fishy real engineering you could look up to verify or refute that.

A wider and taller tire will have more sidewall showing when aired down then a skinnier shorter tire.

My 295/70/17's are 33.3 inches tall. They have an aspect ratio of 8.1".

A 315/75/16 is 34.6 inches tall. It has an aspect ratio of 9.3.

Assuming the same rim diameter tell me what happens when you air them both down to 12 PSI? Which one has more sidewall bulge past the rim?

Hope that clears some things up for you. lol

 

[theesotericone]

[MENTION=143526] don't really travel any faster than, let's say 75 mph. :spy: Where would that put me RPM wise with 5.29? I suppose that is a bit of a loaded question not knowing what size tire I will end up with.

It's not loaded. It's an unknown that you have all the control in the world over.

To answer your question I'll give you my RPM's on the highway at 75MPH with my 295/70/17's(33.3"). In OD it stays at 2800-2900 RPMs. When I hit a long hill it drops to 3rd and my RPMs hit 4000-4100. With my stock 4.10 gears I couldn't use OD at all. So I was always running 3300-3400 RPM's in 3rd gear on the highway. My gas mileage went up when I switched to 5.29's.

Get out your calculator and do some math. First figure out a baseline of your speed and RPM's with your current tires. Knowing that you can do this.

New tire size/current tire size x current RPM's = New RPM's

New gear set/old gear set x current RPM's = New RPM's

That's all I did to figure out where I would be running RPM wise with the new gears. I wasn't changing tire size but the math will still work either way.

For where I live the 5.29's where the best choice for me. It also allows me to still have a bit of power if I step up to 37's for wheeling. This is one of those things you can, and should, research for weeks in your spare time. I went against the age old addage of 4.88's for 33's and I'm really glad I did. YMMV.


EDIT: And lock the frikkin front if your dropping that much money. The extra 900 bucks will save your ass eventually.