Torque Monsta Buying Guide · Detailed guide
Wheel Fitment Basics
A clear introduction to diameter, width, offset, PCD, centre bore and clearance for safer wheel selection.
Measure first
What to measure or record
Record current wheel diameter, width and offset (for example 18x8 ET45), PCD, centre bore, tyre size and suspension/brake setup. Measure inner clearance to strut and caliper, outer clearance to arch, and clearance at full lock and suspension compression. A straightedge across the arch and a ruler to the tyre/wheel give a useful outer-clearance figure.
Decision guide
Choose by intended use
Near-OE road fit
Keep rolling diameter, load rating and offset close to approved fitment for predictable clearance and steering.
Flush road fit
Use measured inner/outer space; allow for tyre sidewall shape, load and suspension movement.
Brake clearance
Use the brake manufacturer’s printable wheel template where available; diameter alone does not prove spoke/barrel clearance.
Track fit
Prioritise tyre availability, brake cooling, low mass and repeatable clearance over maximum visual width.
Understand what you are buying
Key terms explained simply
PCD
Bolt pattern, such as 5x112; it must match.
Centre bore
Locates the wheel on the hub.
Offset ET
Positions the wheel relative to its centreline; width must be considered with it.
Backspacing
Mounting face to inner edge, useful for strut clearance.
Rolling diameter
Overall tyre diameter affecting clearance, gearing and speed indication.
Load rating
Approved maximum load per wheel or tyre.
The essential measurements
PCD defines the bolt pattern, centre bore locates the wheel, and offset controls where the wheel sits relative to the hub. Diameter and width must also suit the tyre and available space.
Clearance matters
Check the inner barrel against brake calipers, the inner rim against suspension, and the outer tyre against the arch through steering and suspension travel. A matching bolt pattern alone does not guarantee fitment.
Tyre sizing
Changing wheel size may require a different tyre profile to retain an appropriate overall rolling diameter and load rating. Consider speedometer accuracy, gearing, comfort and rim protection.
Spacers and hardware
Use hub-centric components where specified and the correct bolt or nut seat, thread and engagement. Recheck torque after the initial bedding period according to the hardware manufacturer’s instructions.
Straight answers
Frequently asked buyer questions
What does ET mean?
Offset in millimetres. On equal-width wheels, lower ET moves the wheel outward. If width changes, calculate inner and outer movement as well.
Will the same diameter clear my brakes?
Not necessarily. Barrel and spoke shape control caliper clearance. Use a brake template or trial fit.
How much arch clearance is enough?
Enough for lock, bump travel, body roll, tyre growth and passenger/load weight. Parked clearance is not proof.
Can spigot rings correct any wheel?
They can adapt an appropriate larger centre bore. They cannot fix wrong PCD, offset, fixing seat or load rating.
Do I need different bolts?
Possibly. Thread, seat, shank length and engagement must match both hub and wheel.
Information to have ready before ordering
These details help us confirm the right product and avoid preventable fitment mistakes:
- Vehicle and exact derivative
- PCD, centre bore and fixing-seat type
- Current wheel diameter, width and ET
- Proposed wheel diameter, width and ET
- Current and proposed tyre sizes
- Inner strut, caliper and outer arch clearance
- Brake template if modified
- Suspension height, camber and spacers