Can I run 16” or 18” rims on my stock 1993 4Runner?

I really want to go to either a 16 inch or 18 inch wheel on my stock 4Runner. Can I run either one of these sizes without any modifications?

 

You can but keep in mind you will probably have to re-gear both the front and rear differentials;
check out 4lo.com the site has got great info bigger tires on their trucks and what gear ratios the should be running to maintain as close to OEM performance.

 

Umm why on earth would he need to regear from changing the WHEEL size???

 

I’m assuming the stock wheel was 15”? If so, yes you can run a larger wheel with no issues. Usually, problems arise when trying to run smaller wheels that may not clear hub components.

 

Welcome.

 

Lol family guy beat me to it.

 

Let me preface my response by saying that I learned all of this the hard way - by trial and error & spending a lot of $$$$ to get it right and some humility thrown in for good measure! might be a little long winded but bear with me

I didnt have to do this with my 1988 4Runner 22RE a vehicle I owned for 25 years! - she had factory 31"s & 4.56 gears; when I put 33's on the 88 all I had to do was grind what's called the pinch welds on the insde of the fender wells to keep tires from rubbing - there was no noticeable loss of power / throttle response with the bigger tires.

So after my Bronco experience rebuilding to OEM Ford specs, driveline, transfer and axle gearing etc; exception being a 5.4 Coyote H.O. motor.

Having the Bronco turn out as nice as she did I thought I knew all I needed to when I sought out to buy another 4runner in January; this time with eyes toward building up a mudder not a street Queen like the Bronco .

I had had a 92 4R w/all the bells and whisltes it ran great and I sold it for more than I paid while I was working on Bronco -got bored and wanted to build another 4runner but not being able to find another 1st gen like I wanted.

I kept coming back to this clean 1991 2nd gen that I knew was for sale & figured hell I got this!.. did my due dilligence I thought - all was good - front suspension had been recently rebuilt - hell radiator even had Red toyota coolant - not the green generic stuff
(another time I'll post about coolant for toyotas)

So off to work I go - I work a rotation 4 weeks on 4 weeks off - In my "off time" at work I hatch all my plans - new bumpers to replace rusty old ones, choose which brand and what type of lift kit -it is harder than you think to choose - body/ suspension/ ball joint spacers etc.... order everything and cant wait to get home to start the transformation!
Install the kit - no easy task - 28 years of crud and rust and broken bolts etc... get that part done - replace the bumpers front and rear with shiny new chromies!
now the tires - I wanted specifically Hankook Dynapro MT's - but they are hard to come by in 15" here in Alaska - everything cool for a nearly 30 year old vehicle has to be special ordered and there aint no free shipping to AK! i knew this coming into project but DAMMIT
buddy tells me he will sell me a set of 16's he has got - cheap - good looking after some spit and polish and elbow grease

Finally get my Hankooks 305/70/16

I am all excited to leave the tire shop - Gonna pick up my buddy who lives about halfway to Homer / I'm thinking I got the lift / the tires/ had her detailed while at work / gonna cruise down to Homer it's late May -20 hours of daylight - I am STOKED!!!!!!!

I hit the road and suddenly I realized something is a miss- engine sounds good - I checked everything- what the hell - figure it'll get better and it doesn't then the 1st hill comes and we're talking just a little roller maybe 150 feet in elevation change but a mile plus long- I was in 3rd gear just to get to the top at 45 mph! -the rest of the way I had to get a running start to go up even the smallest grade and forget about using 5th gear -I had to downshift to 4th and was in 3rd too many times just to maintain speed limit!
I was mostly trying to keep from motorhomes running me over on this 2 lane coastal highway with next to no place to pullover or passing lanes.

So instead of a great cruise to Homer all I did was drive to my buddys place - halfway to Homer - the one who sold me the 16"rims -
I've been so full of myself - proud , even arrogant at times over this build- my friends all like my Bronco comment on the paint the performance etc.. but when I get to his place unbeknownst to me is a slice of HUMBLE pie waiting for me!

My friend says looks great -how's she run - makes the comment boy you are pushing some pretty big tires there bud and goes on to ask whether I changed the gearing - No I didnt I replied and he starts laughing - laughing really hard - son he says you better hold to your wallet- I know what you've spent so far but this is really gonna hurt some more! he 's laughing harder and harder -he knew what modifications I was doing- to be putting bigger tires, the lift, then insult to injury that I went with bigger rims too. taht he sold me ... He just laughed and said c'mon money bags let's start looking for gears that'll bring the performance back!
He goes on to inform of the one thing I should've checked that I didnt check before I bought her was what gears she had from factory!

I ask why - he says from experience - he had one about twenty years ago and said it was a dog pulling a small trailer - stock V6 - 2nd generation Toyota trucks & 4runners are relatively heavy vehicles with relatively low power engines, they don't have a lot of excess power to spare, so gearing is very important.

When larger tires are added, without changing to the proper gears, more power is needed to maintain the same level of highway performance which the V6 just doesn't have.

In conclusion

I bought the 91 V6 early March 2019 - 225/75/15 (28" diameter) w/ 4.10 differential gearing front and rear from factory - runs really strong
After spending a buttload of $$$ for modifications 91 V6 305/75/16' (33.1" diameter)
- She looked great But couldn't get outta of its' own way!

But not knowing that the OEM 4.10 gears would be such a factor taught me an expensive and humbling lesson!

Another Crapload of $$$ to get 4.88 gears and have professionally installed & finally she Damn near runs stronger than stock!

Please ask a professional and ask questions I've included the info below and it should give you a general understanding as to why you may have to re-gear. especially with the 2nd generation toyta trucks and 4runners if you want to maintain as close to stock performance as you may be used to.
Don't forget the Speedometer and Odometer will be affected as well if you don't. I learned from my experience too!





Above is a typical 1989 and later VIN plate, located on the driver's door jam.
This one is from a1989 Toyota 4X4. The gear code is circle in red and is G292, which indicates an 8" rear diff with 4.10 gears and a 2 pinion carrier.



Above is typcial earlier model Toyota VIN plate, located on the engine compartment fire wall.
This one is from a friends 1986 Toyota 4X2 truck.
The gear code is circled in white and is G662, indicating 3.07 gears and an 8" diff and 2 pinion open carrier, which is surprising considering that many 4x2 trucks came with 7.5" rear diffs. But some did come with 8" diffs.



The gear code is the best indicator of which tires the truck came from the factory with.
Any sold in the USA came with 4.56 or 4.88 gears came stock with 31x10.5-15 tires or 265/70R-16 tires.


The chart below will help you decode most models of Toyota pickups 4X4s built in Japan and the U.S.
Included are most of the common gear codes found in both 4X4s and 4X2s, but there might be a code which I have not listed. For more available gear codes on Japanese built trucks, check this gear page.
Most Toyotas built through the early 1990s
Second and Third Number, Denotes Gear Ratio

Fourth Number (Letter on later model trucks), Denotes Pinion Type

First Letter, Denotes Gear Size
F=7.5"
G=8"
Second and Third Number, Denotes Gear Ratio
07 = 3.9000
8 = 4.110
10 = 4.375
14 = 4.875
25 = 4.556
28 = 4.300
29 = 4.100
31 = 3.91
38 = 3.42
43 = 3.56
54 = 3.90
66 = 3.07

Once you've determined your gear ratio, the next step is to determine which gear ratio is right for your application. This is a
highly subjective subject.
The following chart shows what gear ratio / tire combination will maintain stock or better performance and applies specifically to 4x4s, with either a 5 speed manual or overdrive automatic made through 1995.
.
What you see recommended below, may not be to your liking depending on your driving style.
Transmission types 5speed Automatic
(A) (B)
225/70R-15 Tires = 4.10 or 4.30 gears
31 x 10.5-15 Tires = 4.56 or 4.88 gears
32 x 11.5-15 Tires = 4.56 or 4.88 gears
33 x 9.5-15 Tires = 4.88 or 5.29 gears
33 x 12.5-15 Tires = 4.88 or 5.29 gears
35 x 12.5-15 Tires = 5.29 gears

For factory stock performance, or near factory stock performance with larger tires,
Selection (A) should be used with 5 speed manual transmissions,
Selection B should be used with automatic transmissions.
For better off road performance and better highway acceleration, selection B should be used, but you will experience higher rpms on the
highway than you may be used too. How these ratios affect fuel economy depends entirely on how you drive and the
weight you carry. In some cases a lower ratio, combined with reasonable driving, will return stock gas mileage, on a
truck with larger tires.

When regearing with an automatic transmission on pre-1995 trucks that have larger tires, it's recommend going with the next lower gear ratio to
maintain factory performance. I.E. if you have 31" tires, you should use 4.88 gears, if you have 33" tires, you should use 5.29 gears.
The lower gearing is recommended to offset the extremely high 1st gear in the automatic and the high overdrive.
Toyota installed 4.30s in stock automatics, while similar 5 speed models got 4.10 gears.

 

Bud, you really need to learn the difference between a wheel and a tire. And I’d probably refrain from offering much advice because i think you’ve still got lots to learn yet. The original poster can absolutely put larger wheels on his ride without needing to regear. You can run a 31, 33, 35, 37, 40, or even a 44 inch tire on a 15,16,17,18,19, or 20 inch wheel.

What size wheel you put the tire on has ZERO effect whatsoever on what gearing you need.

 

/Endthread.

 

I disagree
The increased size causes the tires to rotate slower to cover the same amount of ground. It will take more power to accelerate because your drivetrain’s mechanical advantage has been decreased. If you are running an automotive transmission this can cause some serious strain depending on the current gear ratio if you choose not to regear your system.

Other Systems Negatively Impacted by Tire Size Changes
It’s important to note that all of the systems connected can experience increased wear when the overall balance that keeps them working together well is thrown off.

A short list of those systems and components includes:

• CV or U Joints
• Axle Shafts
• Ring and Pinion Gears within the Differential
• Brakes
• Drivetrain
• Transmission

While the impact on certain systems can be minor, the potential wear is increased significantly if you are changing size for a 4x4 vehicle.

Again by changing the diameter and thus the circumferance (the outside dimesion of the the rim /tire) has a direct impact on gear ratio along with performance of the vehicle! Unless you are running a diesel with a lot of torque then the only issue would be your speedometer & odometer being inaccurate!
this is directly from the 4wheeler magazine website
http://www.fourwheeler.com/how-to/1211or-why-change-gear-ratios/

 

here is another link validating my point!
https://www.4wheelparts.com/a/gear-ratio-tire-diameter

 

You are over thinking this. You do not need to regear if tire size stays similar to factory. End of story.

 

One good thing. Speedo off means you can get a speeding ticket dropped to defective equipment. With a calibration document. I’ve done this twice.

 

I went from the stock 17 x 9.5" wheels with 265/70/R17 tires to 20 x 9" wheels with a +19 offset and Toyo Open Country AT2 at 275/55/R20 tires.

So, while the wheel diameter is 3" bigger the sidewall height is shorter which keeps the total outer diameter of the wheel/tire combination within .3" of the stock OEM setup. They did have to shave the inside of the front bumper a bit to accommodate the wider tires because they rubbed a bit when counter locking the steering wheel in either direction. Beyond that, I've made no changes at all to gearing and it runs as it did on stock wheels / tires.

Here's a great tool for making comparisons between tire / wheel setups that will keep you out of trouble: Click on the Comparison tab and enter your current set up in the first row and what you're considering in the second row. It'll tell you exactly what changes and how much. Even shows how the speedometer will be impacted by the change.

 

Bollocks, the plus sizing of wheel size diminishes the sidewall section height when you maintain your overall circumference of the OEM wheel and tire combination as a goal. I would seriously be looking at the overall change in inertia of the rolling mass because that will have an impact on your ability to accelerate and decelerate the vehicle. By decreasing the mass at the flywheel on the engine and your tire and wheel combinations mass you will have a quicker truck in the lower gears that you can feel. It will stop faster as well. The last thing you want to do is increase the flywheel effect of your tires and wheels if you want to be able to start and stop quickly.

So, if the combination of choice is a rubber band sized tire on a massively plus sized wheel the inertial compliment may be less than the OEM and that could be a good thing. On the flip side once you put energy into your rolling stock it will take energy input to maintain it so that means you might be able to carry your speed into a hill until the inertial complement is spent and then its motor torque needed to maintain your speed i.e less flywheel effect. Not to mention the fact that the off-road ride comfort will suffer but your on-road road feel will increase with a plus sized wheel change and OEM sized tire diameters. I am certain that is not the way to go with off road tire performance when negotiating terrain and airing down. For those of you who just think bigger is better and I mean by installing a larger outside diameter tires over the OEM size your into a world of hurt performance wise! Sure you might clear bigger rocks on the trail and get enhanced approach/departure angles and more over center clearance but the rig will be a pig when its time to move and stop. It may seem impervious to getting stuck with "big" rubber, but brake fade will be a very real occurrence with aggressive twisty road driving.

At 2-1/2 tons the 2nd Gen 4Runner is quite heavy and the 15 inch OEM wheels do limit the functional diameter of the swept area as the brake has to clear the rim and still grip the rotor with the 4 piston caliper and pads. Post ≥ 07/1991 got the larger Ø 25 mm pistons in the caliper and the thicker 25 mm vented rotors. Prior ≤ 06/1991 the pistons are Ø 23 mm and the rotors are 20 mm thick when new. I just replaced my front brake hardware with the bigger stuff. But with plus sized wheels the search for a bigger rotor and offsetting of the caliper to meet would be a keen way to increasing the stopping performance. Land cruiser models with OEM wheels in this plus sized range would be a place to look for hardware.

And the quest goes on!...