OEM Safe
Within ±3%
Inside factory tolerance — ABS, ESP and cruise control stay calibrated.
Fitment comparison
265/40 R21versus315/30 R22
Δ Ø +2.4 mmSpeedo +0.32%OEM-safe
315/30 R22 stands taller than 265/40 R21 — bigger rolling diameter, slightly more clearance, calmer cruise revs.
Plus-sizing from 265/40 R21 to 315/30 R22 keeps overall diameter close to factory while opening room for a larger 22-inch wheel. This alternative fitment barely shifts the rolling circumference. The shorter sidewall gives the tire a firmer, more responsive feel and sharpens steering input.
The dashboard reading stays essentially unchanged from the OEM calibration. Overall the swap sits inside the safe ±3% diameter window, so ABS, traction control and gearing behave normally.
TakeCommon upgrade for sportier handling and a tighter wheel-gap look on the same vehicle.
Quick fitment verdict
265/40 R21 → 315/30 R22 at a glance
Fender Clearance
Likely rubs
Significantly wider/taller — rubbing risk on liners or fender lip is real.
Speedometer Impact
+0.32%
At a true 100 km/h the dash reads 100.3 km/h — negligible.
Daily Driving
Livable
Daily use is fine; expect a slightly different ride and cruise rev count.
Side-by-side telemetry
Dimensional read-out
Current
265/40 R21
- Diameter
- 745.4 mm
- Sidewall
- 106.0 mm
- Wheel
- 21″
- Width
- 265 mm
Δ delta
Ø +2.4 mm
SW -11.5 mm
RH +1.2 mm
NewNew
315/30 R22
- Diameter
- 747.8 mm
- Sidewall
- 94.5 mm
- Wheel
- 22″
- Width
- 315 mm
Real-world effects
How this swap actually feels
- Steering response80/100 · Sharper turn-in
- Ride comfort40/100 · Firmer ride
- Fuel economy9/100 · Slightly higher drag
- Highway cruising61/100 · Lower cruise revs
- Pothole resistance33/100 · Less wheel protection
Shareable card
Generate fitment card
Export a garage-grade telemetry card of this comparison — perfect for forums, Reddit and Discord.
Ride height
Lifted stance
Chassis sits higher — slightly more clearance, wheel-gap visually grows.
New tire lifts the chassis by ~1.2 mm — more clearance, slightly more wheel-gap.
Suspension travel · arch clearance
Wheel gap
Wheel gap stays virtually unchanged
How the arch-to-tire gap reads from across the parking lot — the visual stance change everyone notices first.
265/40 R21
315/30 R22
Wheel-gap Δ+1.2 mm
Static · unloaded chassis
Fender relationship
Tucked · Flush · Poke
The visual relationship between the tire's outer edge and the fender lip — the lens enthusiasts use to judge a fitment.
Tucked
Inside fender
Flush
Lip-aligned
Poke
Outside fender
Width & offset dependent
Speedometer reality
Dash reads 100.3 km/h
Taller rubber: at a true 100 km/h your dashboard reads optimistically high.
ABS · ESP · cruise control
Setup telemetry
How this setup changes the car
Driver-perspective read-out of the 265/40 R21 → 315/30 R22 swap — steering, comfort, stance and dash behavior in plain enthusiast language.
Steering feel
-11.5 mm sidewallSharper steering response
Shorter sidewall transmits inputs faster — quicker turn-in, more confident on-center feel.
Ride firmness
40% → 30%Slightly firmer over rough pavement
Expect more chatter on broken tarmac and a sharper pothole strike — keep an eye on wheel damage risk.
Fender relationship
+50 mm widthWheel sits closer to the fender
Wider tire pushes the contact patch outboard — flusher stance, but verify fender lip clearance at full lock.
Speedometer behavior
+0.32%OEM-safe speedometer reading
Inside the factory ±3% tolerance — ABS, ESP and cruise control behave as designed.
Daily drivability
Ø +2.4 mmLivable upgrade with minor trade-offs
Daily use is fine; expect a slightly different cruise rev count and a touch more road feel.
Direct answer
Is 315/30 R22 OEM-safe?
Yes. Overall diameter changes by +0.32% versus 265/40 R21. OEM-safe. Speedometer, ABS, ESP and gearing remain inside the factory tolerance.
Direct answer
Will 315/30 R22 rub?
Possibly. Width changes by +50 mm and diameter by +2.4 mm. Possible rub at full lock or full suspension compression — verify fender lip and inner strut clearance before committing.
Direct answer
Does the speedometer change?
Yes — by +0.32%. Swapping 265/40 R21 for 315/30 R22 changes overall diameter, so at an indicated 100 km/h your true speed becomes 100.3 km/h. That's within the ±3% OEM tolerance — no recalibration needed.
Direct answer
Does lower sidewall affect comfort?
Yes — firmer ride. Sidewall changes by -11.5 mm (40% → 30%). Ride becomes firmer and steering sharper, but potholes and expansion joints hit harder and wheel damage risk rises.
Current Tire
265/40R21
New Tire
315/30R22
Fitment · Scaled comparison
● Excellent fit
265/40 R21
Diameter
+2.4 mm
+0.32%
Sidewall
-11.5 mm
Speedometer
100.3 km/h
at true 100
Clearance
Excellent fit
315/30 R22
Ground line · Scaled comparison
Excellent Fit
Within ±3% — safe for daily driving
Diameter change
+2.4 mm
0.32%
Speedometer at 100
100.3 km/h
+0.32% error
Ground clearance
+1.2 mm
ride height delta
Sidewall change
-11.5 mm
revs/km: 425.7
Permalink for this comparison:
/compare/265-40-r21-vs-315-30-r22Detailed comparison
| Metric | 265/40 R21 | 315/30 R22 | Difference |
|---|---|---|---|
| Overall diameter | 745.4 mm | 747.8 mm | +2.4 mm (+0.32%) |
| Sidewall height | 106.0 mm | 94.5 mm | -11.5 mm |
| Circumference | 2.342 m | 2.349 m | +7.5 mm |
| Revs / km | 427.0 | 425.7 | -1.4 |
| Ground clearance | reference | +1.2 mm | +1.2 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 100.3 km/h | +0.32 km/h |
Verdict: excellent
Within ±3% — speedometer, ABS and traction control should behave normally.
Dimensional comparison
Side-by-sideScaled engineering side-profile of both tires. Width, sidewall and overall diameter are dimensioned so you can see the change at a glance — without parsing the numbers.
Current
265/40 R21- Profile
- 40%
- Circumference
- 2.342 m
New
315/30 R22- Profile
- 30%
- Circumference
- 2.349 m
Side-by-side fitment
GeometryCurrent
265/40 R21- Section width
- 265 mm
- Aspect ratio
- 40%
- Sidewall
- 106.0 mm
- Wheel diameter
- 21″(533 mm)
- Overall diameter
- 745.4 mm(29.35″)
- Circumference
- 2.342 m
- Revs / km
- 427.0
New
315/30 R22- Section width
- 315 mm
- Aspect ratio
- 30%
- Sidewall
- 94.5 mm
- Wheel diameter
- 22″(559 mm)
- Overall diameter
- 747.8 mm(29.44″)
- Circumference
- 2.349 m
- Revs / km
- 425.7
Real-world consequences
Pros / consWider tire (+50 mm)
Section width- More dry grip and cornering bite
- Sharper steering response on initial turn-in
- Bigger contact patch under braking
- More road noise on coarse asphalt
- Worse aquaplaning resistance in standing water
- Higher rolling resistance, small MPG hit
- Possible fender or strut contact at full lock
Lower profile (-10% aspect)
Sidewall- Sharper turn-in and less sidewall roll
- More planted on smooth tarmac
- Bigger brake / caliper visual real estate
- Harsher ride over expansion joints and potholes
- Higher wheel-damage risk on impacts
- Less curb protection for the rim lip
- More sensitive to correct tire pressure
+1″ rim upsize
Wheel diameter- OEM+ look, fills the arch better
- Sharper response with matching low-profile rubber
- Bigger brake clearance for upgrades
- Heavier wheel, more unsprung mass
- Harsher ride, more wheel-damage risk
- Tire and wheel cost both go up
How it changes driving feel
Seat-of-the-pantsSteering response
Sharper turn-in
Ride comfort
Harsher impacts
Road noise
Louder on coarse asphalt
Wet / aquaplaning
Reduced standing-water margin
Fuel economy
Small MPG penalty likely
Curb / pothole protection
Higher wheel-damage risk
Fitment risk check
Verify before installFender rubbing
Width jump >20 mm — verify fender lip and inner liner clearance at full lock.
Suspension clearance
Wider tire may contact strut or control arm on full compression.
Cluster preview
Within toleranceSpeedometer impact
At a true 100 km/h, your dashboard will read 100.3 km/h after switching to 315/30 R22 — a +0.32% offset. Use the speedometer error calculator for any indicated speed, and the speedometer error guide for the full background.
Ground clearance change
The new tire's half-diameter changes ride height by +1.2 mm. Small differences are absorbed by suspension travel, but anything beyond ±10 mm can affect headlight aim, fender clearance and bump-stop margin. See the plus-sizing guide before committing.
Back to
265/40 R21
Back to
315/30 R22
Drivers also compare
Closely-related fitments and plus-size swaps for 265/40 R21 and 315/30 R22.
275/35 R22 vs 315/30 R22
Wider variation on the same rim — more grip, less clearance.
Δ 0.47%
265/35 R22 vs 315/30 R22
Wider variation on the same rim — more grip, less clearance.
Δ 0.47%
265/40 R21 vs 295/35 R21
Wider variation on the same rim — more grip, less clearance.
Δ 0.74%
285/35 R22 vs 315/30 R22
Wider variation on the same rim — more grip, less clearance.
Δ 1.38%
295/30 R22 vs 315/30 R22
Wider variation on the same rim — more grip, less clearance.
Δ 1.63%
265/40 R21 vs 285/35 R21
Wider variation on the same rim — more grip, less clearance.
Δ 1.68%
265/40 R21 vs 275/35 R21
Wider variation on the same rim — more grip, less clearance.
Δ 2.62%
275/40 R22 vs 315/30 R22
Wider variation on the same rim — more grip, less clearance.
Δ 3.98%
Related topics
Comparison hub
Back to the tire size comparison calculator
Browse every wheel and tire fitment comparison, by rim size or popularity.