2017 Mercedes-Benz SL450 — Roadster
The 2017 Mercedes-Benz SL450 Roadster shipped with 4 different factory tire sizes, depending on the wheel package it left the factory with (this can also reflect a staggered front/rear setup). Check your tire sidewall or door placard to confirm which one applies to your vehicle.
This trim shipped with more than one tire size (staggered fitment, front/rear, or optional wheel package). Confirm which one matches your vehicle by checking your tire sidewall or door placard.
255/40R18 (Front)
| Section width | 255 mm |
|---|---|
| Aspect ratio (sidewall height) | 40% (102 mm) |
| Rim diameter | 18" |
| Overall tire diameter | ~26" |
| Revolutions per mile | ~775 |
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285/35R18 (Rear)
| Section width | 285 mm |
|---|---|
| Aspect ratio (sidewall height) | 35% (99.8 mm) |
| Rim diameter | 18" |
| Overall tire diameter | ~25.9" |
| Revolutions per mile | ~780 |
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255/35R19 (Front)
| Section width | 255 mm |
|---|---|
| Aspect ratio (sidewall height) | 35% (89.3 mm) |
| Rim diameter | 19" |
| Overall tire diameter | ~26" |
| Revolutions per mile | ~775 |
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285/30R19 (Rear)
| Section width | 285 mm |
|---|---|
| Aspect ratio (sidewall height) | 30% (85.5 mm) |
| Rim diameter | 19" |
| Overall tire diameter | ~25.7" |
| Revolutions per mile | ~784 |
Compare prices at:
What this size means for your Mercedes-Benz SL450
On the 2017 Mercedes-Benz SL450 Roadster, the factory 255/40R18 measures about 26″ in overall diameter with a 102 mm (4″) sidewall, and completes roughly 775 revolutions per mile. Its 40-series aspect ratio gives a low-profile sidewall tuned for sharper handling, common on sport trims and larger-wheel packages. In tire terms it is a passenger (P-metric / Euro-metric) size.
This is a staggered setup: the front axle runs 255/40R18 and the rear runs 285/35R18. The two sizes are not interchangeable, so order each for its correct axle and don't rotate front-to-rear.
Mercedes-Benz SL450 tire sizes by year
- 2020 Mercedes-Benz SL450 255/35R19 (Front) / 285/30R19 (Rear)
- 2019 Mercedes-Benz SL450 255/35R19 (Front) / 285/30R19 (Rear)
- 2018 Mercedes-Benz SL450 255/35R19 (Front) / 285/30R19 (Rear)
How to read a tire size
A tire size like 225/45R17 breaks down into three parts:
the first number is the section width in millimeters
(the tire's width from sidewall to sidewall), the second is the
aspect ratio — the sidewall's height as a percentage of
that width — and the number after the "R" is the rim
diameter in inches. A letter prefix (P or LT) indicates
Passenger or Light Truck construction; its absence usually means
Euro-metric sizing.
Some trucks and off-road tires instead use "flotation" sizing, like
37X12.50R17 — here the numbers are the tire's overall
diameter and width in inches directly, with the rim diameter last.
Always verify against the tire information placard on your driver's-side door jamb or your owner's manual before purchasing — tire size can vary by factory option package even within the same trim.