2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package
The 2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package tire size and wheel specifications below reflect standard OEM reference fitment data for this trim level.
Detailed tire and wheel breakdown for the 2017 Alfa Romeo 4C
Tire geometry â 205/40R18
The 205/40R18 fitted to the 2017 Alfa Romeo 4C has a section width of 205mm and an aspect ratio of 40%, mounted on a 18-inch rim. That gives a sidewall height of 82.0mm (3.23") and an overall outside diameter of 621.2mm (24.46"). At highway speed this tire completes roughly 512 revolutions per kilometre, which is what your speedometer and odometer are calibrated against.
Plus-sizing window
If you want to upsize wheels on the 2017 Alfa Romeo 4C while keeping the speedometer accurate, target a 215/32R19 (plus-one). For a softer ride or winter setup, a 195/49R17 (minus-one) keeps the overall diameter within Âą3% of stock, which is the industry tolerance for ABS and stability control to stay calibrated.
Wheel fitment specs
The 2017 Alfa Romeo 4C uses a 5x98 bolt pattern with a 58.1mm hub bore. Safe rim width range for the OEM tire is 6.5J â 7.5J, and offsets in the ET28 â ET38 window will clear suspension and fender without rubbing on most setups.
Staggered setup notes
The 2017 Alfa Romeo 4C ships staggered: 205/40R18 up front and 235/35R19 on the rear. That is a 235mm vs 205mm width difference â do not rotate front-to-rear, and replace tires in axle pairs to keep ABS and traction control balanced.
Tire pressure guidance
Manufacturer-recommended cold tire pressure for the 2017 Alfa Romeo 4C is printed on the driver-side door jamb sticker â always defer to that value, not to the maximum pressure printed on the tire sidewall. Check pressure monthly and before long trips; under-inflation by 20% can reduce tread life by 25%.
Fitment Specifications
| Engine & Trim | Tire Size | Rim Size | Offset (ET) |
|---|---|---|---|
| 1.75 TBi Spider / Racing Package | 205/40R18 Rear: 235/35R19 | 18" x 7.0 | ET33 |
Frequently Asked Questions
What tire size does the 2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package use?
The 2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package uses 205/40R18 tires as standard equipment.
What is the bolt pattern of the 2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package?
The 2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package has a 5x98 bolt pattern with a center bore of 58.1mm.
What is the wheel offset of the 2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package?
The 2017 Alfa Romeo 4C 1.75 TBi Spider / Racing Package has a wheel offset of ETET33.