Why would you want to fit 33 inch tires on a Hilux? Simply put, because the look good and you can! These machines have built up a reputation for reliability, durability and capability. One way to make these machines perform and look even better is by doing a big tire upgrade! So how do you make them fit?
A Hilux N70 (D4d) can accommodate 33” tires with a 3” lift combined with a 2″ leveling kit. A Body mount chop combined with some wheel arch trimming is necessary to prevent rub at full compression and at full lock.
Fitting bigger tires is one of the most popular upgrades to increase ground clearance as well as approach and departure angles. Unfortunately, big tire upgrades are not always a straight forward process. With the Hilux being an IFS setup, you are limited to how high you can go before you compromise your CV angles, so let’s look at what is required to make 33” tires work flawlessly on a N70 Hilux SR5 (D4d).
Can You Fit 33s On a Hilux?
The SR5 Hilux has decent wheel arch clearance which allows you to fit bigger tires without too much hassles, provided you know what you’re doing. So, let’s look at the minimum requirements to make those 33’s work
Minimum Suspension Lift for 33” Tires on a Hilux
When it comes to fitting 33’s you have a few options available, each with its advantages and disadvantages. If, for example, your Hilux is stock and you intent on fitting an aftermarket suspension with the intention of fitting 33’s then opt for a 3” kit off the bat. This allows you to fit 33’s with the least amount of additional trimming and cutting.
If you have an existing 2” suspension upgrade, let’s say a 2” OME suspension kit, then you’ll need to either install a 2” body lift or a 2” leveling kit. The leveling kit will be the cheapest and quickest option. In this instance you’ll still be required to do some light trimming on the fenders as well as body mounts, but not extensively. With a 2inch OME lift. After trimming all the necessary bits it still rubs the body mounts at full lock. This will be quite noticeable when doing rough tracks especially under full compression.
With a 3” suspension and a body lift, you won’t require to do any extensive trimming or cutting at all. When you combine the 3” suspension with the 3” body lift, you will not have any scrubbing, even under full compression, since there is enough room for the wheels to travel and compress.
What about your UCA? Will they clear?
UCA (Upper Control Arms) and 33’s on your Hilux
When fitting 33’s, always remember the movement and room required to clear the UCA. The biggest issue with your tires is hitting the UCA at the front when at full lock. An aftermarket adjustable UCA will allow more room on the inner side of the tire, which also offers you the option to fit a slightly more positive offset wheel and keep it tucked inside the guards and street legal.
A more negative offset wheel will give you a more aggressive stance and probably more stability, however you’ll then need to fit wider arch flairs to keep it legal, since they will poke out quite a bit. Alternatively, a zero offset rim is perfect to run 285’s on a 16×8 inch rim with factory UCA’s.
The aftermarket UCA also allows you to set the caster angle further forward in order to clear the body mount better. In my case, I had to set mine completely forward to clear 100%. With a 2″ lift getting caster is not a problem, however once you go 3″ the IFS geometry is thrown out a bit so an adjustable aftermarket UCA is the perfect solution.
Diff Drop Kit on a Hilux
The main problem with IFS suspension upgrades are the CV axles. The diff of an IFS truck is mounted directly against the underside of the chassis. This makes for excellent stability and cornering, however, it limits the downward travel of the wheels and places the CV joints under more stress when the vehicle is lifted too high.
It’s not recommended to go higher than a 3-inch lift kit on an IFS vehicle, and if you do decide to go higher, you’ll need additional modifications such as diff drop kits, adjustable UCA (Upper Control Arms), LCA, and Stabilizer arms.
Trimming the Guards for 33” on a Hilux
With 2+2 suspension and lift options, you will still need to cut the inner guards and some of the metal underneath there to make sure there is zero contact under full compression and full lock. So don’t be afraid to get that grinder out, else you’ll be slicing up your new tires in no time!
If you don’t want to do any cutting, then go 3” suspension combined with a 3” body lift. Even in this instance, depending on the tire, you might still have to do a BMC. The 3” body lift will raise the guard work higher resulting in less trim work.
BMC (Body Mount Chop) to accommodate 33’s
It is recommended to do a small BMC to ensure everything clears underneath at full lock, and especially in reverse. You will need to remove the front mud guards completely and also cut out a section of the inside front guards. The body mount at the rear of the front guards, that’s the limiting factor.
A body lift kit will only lift the cab, however the mount remains the same position it was, and it is the mount that’s really the limiting factor as to the width and height of the tire you’re planning to fit.
Are 33-Inch Tires the same as 285’s (Metric Vs MM)
When comparing a 33” tire to a 285 wide tire, you are essentially talking about two completely different measurements. The 33” refers to the width of the tire (285) multiplied by the height percentage of the sidewall (75), in millimeters, x2 because there are two sidewalls, divided by 25.4 (inches) plus the wheel size in inches (16”). Phew!!! That’s a mouthful and a lot to digest at once so let’s break it down into a simple formula.
YES, 285 wide tires are the same as 33” tires although 285 is the tread width in millimeters and 33″ is the tire diameter. 285/75/16 is usually the accepted metric equivalent size for 33’s.
Let’s see what that looks like in a formula form
285 = the width of the tread in mm
75 = the height percentage of the sidewall in mm (285 width x .75 = 213.75mm)
Divide mm by 25.4 to get inches
So….. 213.75 x 2 sidewalls = 427.5mm (divided by 25.4 = 16.831″)
16.831″ + 16″ wheel = 32.831″ approximate tire diameter.
As mentioned, 285 and 33 are referring to two completely different measurements. . Metric tire sizes can be a bit more complicated when it comes to understanding what size they really are.
Let’s see what that means
Metric vs Millimeters
Because each tire manufacturer uses their own molds, and there’s no set industry pattern, the 285/75/16 is usually the accepted metric size for 33’s, even though the physical diameter of the tire can vary from manufacturer to manufacturer. Two different 285’s can actually vary in true diameter. Meaning some are smaller than 33″ and some are larger, depending on the brand. This means a 33 inch tires can be wider by 11 1/2 or 12 1/2 inches in width.
One way to find out the exact diameter of a tire is by going to the tire manufacturer’s website and checking the manufacturing specs on that specific tire and then comparing “apples with apples”.
Will the 285/75/16 throw out your speedo?
When you upgrade from a stock tire to one with a taller aspect ratio (Side wall), increasing the wheel circumference, your speedo can be thrown out. In the case of 33” tires the diameter will be larger and have an increase in the aspect ratio. This might throw-out your speedometers reading slightly. The increase in tire circumference means the actual speed will be higher the faster you travel.
The below table will give you an indication of how the speedometer reading is affected from a 265/70/16 to a 33”.
Below are the actual differences between the stock 16” tire and the upgraded 285/75/16
|Measurement||Stock Tire (265/70/17)||Upgrade (285/75/16)||Differences|
Big lifts on an IFS Truck
When lifting any IFS truck, the front suspension configuration determines the complexity of the upgrade. In the case of a SFA or LIVE axle, the axle is not physically attached to the chassis. This allows you to fit big tires and higher lifts easier. The CV angles are not compromised since they are always in line with the diff and axle. This allows you to fit 4”, 6” and even higher with less hassles. Fitting 33” tires to a Solid/Live axle truck requires less additional modifications and in most cases little to no Body or arch modifications.
An IFS front axle on the other hand is a more complex process and you are limited. Unfortunately most 4WD’s in production these days are IFS suspensions. Manufactures are more concerned about on road performance and safety so they produce IFS trucks which appeals to a larger market.