P225/45R18
Passenger / P-MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The P225/45R18 tire size features an overall diameter of 25.97 inches, a section width of 8.9 inches (225mm), and rotates 777 times per mile. It is a standard factory tire fitment on 100+ vehicle models including Chevrolet HHR.
Physical Dimensions & Specs
Overall Diameter
25.97"
659.6 mmSection Width
225 mm
8.86" wideSidewall Height
3.99"
101.3 mm (45% aspect)Revolutions / Mile
777
Circumference: 81.59"Rim Diameter
18"
Wheel sizeRecommended Rim Width
5.6" - 7.9"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare P225/45R18 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)225/45R18
Overall Height:26.0"
Sidewall:4.0"
Revs/Mile:777
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
+13.9%At 60 mph reading, actual speed is 68.3 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 22.8 mph | +2.8 mph |
| 30 mph | 34.2 mph | +4.2 mph |
| 45 mph | 51.2 mph | +6.2 mph |
| 60 mph | 68.3 mph | +8.3 mph |
| 75 mph | 85.4 mph | +10.4 mph |
| 90 mph | 102.5 mph | +12.5 mph |
Fender & Suspension Clearance
Fitment Status: MODERATE RISK
Flush fitment. Extends 17.7mm outwards. Check wheel arch clearance under full suspension compression.
Inner Strut Space:7.7mm LESS clearance
Outer Fender Push:Extends 17.7mm further out
Ride Height Delta:+1.80" ground clearance
Vehicles That Fit P225/45R18 (100+ Models)
Factory standard and optional vehicle fitments utilizing P225/45R18 tires: