What is wheel offset (ET)?
Wheel offset (ET) is the distance in millimeters from the wheel's mounting face to its centerline. Positive ET moves the wheel inward toward the suspension. Negative ET moves the wheel outward toward the fender. ET stands for Einpresstiefe.
The ET value is stamped on the back of almost every aftermarket wheel. A wheel that is 8 inches wide has its centerline at 101.6mm from either edge. If the mounting face sits 45mm ahead of that centerline, the offset is ET45. Changing from ET45 to ET35 moves the outer edge of the wheel 10mm further out — this is called poke.
Positive Offset (ET+)
Mounting face sits in front of centerline. Wheel sits closer to the engine and suspension. Typical range: ET35 to ET55 on front-wheel-drive cars.
Negative Offset (ET−)
Mounting face sits behind the centerline. Wheel extends outward toward the fender. Typical range: ET0 to ET−25 on off-road trucks and aggressive stance builds.
How does positive offset affect wheel fitment?
Positive offset pushes the wheel inward toward the suspension and brakes. Higher ET values — ET45, ET50 — create more fender clearance and less poke. Most factory front-wheel-drive cars run ET35 to ET55 to keep wheels flush inside the wheel arch.
Increasing ET by 10mm (e.g. ET35 to ET45) moves the wheel 10mm inward. This gains fender clearance but reduces the gap between the wheel and suspension parts — particularly the control arm, strut, and brake caliper. ET values above ET55 on a wide wheel can cause the inner tire edge to contact the inner fender liner.
How does negative offset affect wheel fitment?
Negative offset pushes the wheel outward past the fender line. ET0 means the mounting face is exactly at the centerline. ET−25 moves the wheel 25mm further out than ET0. Negative offset is used on lifted trucks and off-road builds to widen the vehicle's track width.
Switching from a factory ET45 to ET0 moves the outer face of the wheel 45mm outward. On most stock vehicles this causes fender contact, requiring rolling or trimming. Negative offset also increases the scrub radius, which makes steering feel heavier and increases stress on wheel bearings and CV joints over time.
What is the standard wheel offset for most cars?
Most front-wheel-drive cars use ET35 to ET50. Rear-wheel-drive performance cars use ET20 to ET40. SUVs and crossovers use ET40 to ET55. Pickup trucks run ET18 to ET30. Off-road and lifted trucks use ET0 to ET−25 depending on fender clearance and lift height.
| Vehicle Type |
Typical ET Range |
Fitment Style |
| Front-Wheel-Drive Cars | ET35 – ET55 | Flush to tucked |
| Rear-Wheel-Drive Sports Cars | ET20 – ET40 | Slight poke to flush |
| SUVs & Crossovers | ET40 – ET55 | Tucked |
| Pickup Trucks (stock) | ET18 – ET30 | Near flush |
| Lifted Trucks / Off-Road | ET0 – ET−25 | Aggressive poke |
| JDM / Stance Builds | ET−10 – ET−40 | Aggressive poke |
What is the difference between wheel offset and backspacing?
Wheel offset (ET) measures from the mounting face to the wheel centerline in millimeters. Backspacing measures from the mounting face to the inner wheel edge in inches. Both describe the same wheel position but use different reference points and measurement units.
To convert backspacing to ET: ET (mm) = (Backspacing × 25.4) − (Width × 25.4 ÷ 2). Example: an 8-inch wide wheel with 5.5 inches of backspacing = (5.5 × 25.4) − (8 × 25.4 ÷ 2) = 139.7 − 101.6 = ET38. The American truck and off-road market commonly uses backspacing. ET is the global standard used by European and Asian manufacturers.
How much wheel offset change is safe without rubbing?
A safe offset change for most daily drivers is within ±10mm of stock ET. Changes of ±15mm may require fender rolling. Changes beyond ±25mm typically need fender modification, wheel spacers, or suspension changes to prevent tire contact with fender or suspension parts.
- ±0–10mm from stock ET — Safe for most vehicles, no modification needed
- ±11–15mm from stock ET — Check clearance; fender rolling may be needed
- ±16–25mm from stock ET — Fender rolling or trimming likely required
- ±25mm+ from stock ET — Fender modification or aftermarket suspension required
What happens if wheel offset is too high?
If offset is too high (too positive), the inner tire edge rubs against the suspension, brake caliper, or inner fender liner. Symptoms include rubbing noise during cornering or at full steering lock, uneven inner tire wear, and reduced steering angle on some vehicles.
What happens if wheel offset is too low?
If offset is too low (too negative), the outer tire edge rubs against the fender lip — especially during suspension compression or hard cornering. This causes fender scraping, tire sidewall damage, and in most countries places the wheel outside legal fender coverage limits.
How does wheel offset affect handling and steering?
Wheel offset changes the scrub radius — the distance between the steering axis and the tire contact patch. Lower ET increases scrub radius, making steering feel heavier and more reactive. Higher ET reduces scrub radius, giving lighter and more stable steering at the expense of stance width.
On front-wheel-drive vehicles, lowering ET significantly below stock can cause torque steer — pulling during hard acceleration. On rear-wheel-drive vehicles, lower ET widens the track which improves cornering grip but increases bearing and CV joint stress. Stay within ±15mm of stock ET to keep handling characteristics safe for daily driving.
Use the tire size calculator on our homepage to also check how your new tire size affects speedometer error and ride height alongside your offset change.
