A lot of our phone calls start the same way. "I need two tyres for a loader, how much?" The honest answer is that we cannot say until we know the size, and on an OTR tyre the size is more than one number. Two tyres that both fit a 25-inch rim can differ in width, construction, strength and tread depth, and the price difference between them can be large.
This guide walks through what is moulded on the sidewall of an off-the-road tyre, in the order you will usually find it, so that you can read it yourself and send your supplier everything needed for an accurate quote the first time.
There are three ways OTR sizes are written
Construction and mining tyres grew up under several standards, so you will see three styles of size marking on Pakistani sites. All three end with the rim diameter in inches.
1. Conventional sizes: 17.5-25, 23.5-25, 14.00-24, 18.00-33
This is the most common style on loaders, graders and dumpers in Pakistan. The first number is the nominal section width in inches, and the last is the rim diameter in inches. So a 17.5-25 is roughly 17.5 inches wide and fits a 25-inch rim.
Within this style there are two families. Sizes ending in .5 such as 17.5-25, 20.5-25 and 23.5-25 are "wide base" tyres, with a sidewall height of around 80 percent of the width. Sizes ending in .00 such as 14.00-24 and 18.00-25 are "narrow base" tyres, with a taller sidewall close to the full width. You will see wide-base sizes on most wheel loaders and narrow-base sizes on graders, cranes and many dump trucks.
2. Low-profile sizes: 16/70-24, 16/70-20
Here the middle number is the aspect ratio. A 16/70-24 is 16 inches wide, with a sidewall 70 percent of that width, on a 24-inch rim. These are common on compact loaders and telehandlers.
3. Metric sizes: 750/65R25, 405/70R24
Newer, mostly radial sizes are written like car tyres. A 750/65R25 is 750 mm wide with a 65 percent sidewall on a 25-inch rim. You will see these on articulated dump trucks and some modern loaders.
The dash or the R: bias or radial
The character between the width and the rim tells you how the tyre is built.
- 17.5-25 (dash) is a bias or cross-ply tyre. Its body plies run diagonally and cross each other.
- 17.5R25 (R) is a radial. Its body plies run straight across, with steel belts under the tread.
The two are the same nominal size and fit the same rim, but they behave differently and should never be mixed on the same axle. We have a separate article on when bias or radial makes more sense.
Ply rating and star rating: strength, not layers
On a bias tyre you will see something like 20PR or 16 PLY RATING. This is a strength index. It tells you how much load the tyre can carry at a given pressure. It does not mean there are literally 20 layers of fabric inside; modern materials reach the same strength with fewer plies.
Radial OTR tyres usually use stars instead: one star (★) for lighter, faster duty and two or three stars for heavier loads at lower speed. A higher ply or star rating carries more load, but it also costs more and rides stiffer, so more is not automatically better.
When you ask for a quote, give the ply or star rating from your current tyre. If you only give the size, two suppliers may quote different ratings and the prices will not be comparable.
The TRA code: what the tyre is designed to do
Somewhere on the sidewall you will usually find a short code such as L3, E3, G2 or L5. The letter shows the type of machine and the number shows the tread type and depth. An L3 is a loader tyre with a standard rock tread, an L5 is a loader tyre with an extra-deep tread for abrasive faces, and so on. This code matters as much as the size. We explain it in full in our TRA code guide.
Tube-type or tubeless
Look for TT (tube type) or TL (tubeless). Many bias OTR tyres in Pakistan still run with a tube and flap, while others run tubeless on multi-piece rims. Tell your supplier which you use, and whether you need new tubes, flaps or O-rings with the tyres. Fitting a new tyre with an old, stretched tube is a common cause of early failure.
A worked example
Take a tyre marked 17.5-25 20PR L3 TL. Reading left to right:
| Marking | Meaning |
|---|---|
| 17.5 | Nominal width about 17.5 inches (wide-base family) |
| - | Bias (cross-ply) construction |
| 25 | Fits a 25-inch rim |
| 20PR | Ply rating 20, a heavy-duty strength index |
| L3 | Loader tyre, standard rock tread |
| TL | Tubeless |
That is a typical tyre for a 3-ton class wheel loader working at a crusher or stockpile.
What to send for an accurate quote
The fastest way to get a correct price is to take a clear photo of the sidewall where the size is moulded, and send it with these details:
- Full size, including the dash or R
- Ply rating or star rating
- TRA code, if visible
- Tube-type or tubeless
- Machine make and model, and the main job it does
- Quantity, and the city or site for delivery
With that, a supplier can quote like-for-like, offer sensible alternatives if your exact tyre is not available, and avoid the back-and-forth that holds a machine up for days.
Need a price on these tyres?
Send a sidewall photo or your size list. Quotes usually within one business day.