225/45R17 vs 245/40R17
245/40R17 is 6.0 mm shorter than 225/45R17 in overall diameter (−0.9%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 245/40R17 fitted, the speedometer reads 100 km/h when you are doing 99.1 km/h.
Dimensions side by side
| 225/45R17 | 245/40R17 | |
|---|---|---|
| Overall diameter | 634 mm (25.0″) | 628 mm (24.7″) |
| Section width | 225 mm | 245 mm |
| Sidewall height | 101 mm | 98 mm |
| Rim | 17″ | 17″ |
| Revolutions per km | 502 | 507 |
| In stock | 59 tires from $101.00 | 15 tires from $115.00 |
What changes
- Overall diameter: 245/40R17 is 6.0 mm shorter (−0.9%).
- Speedometer: reads 100 km/h at an actual 99.1 km/h with 245/40R17.
- 245/40R17 is 20 mm wider, so check clearance and the recommended rim width.
- Choose a load index at least as high as the one on your door placard.
Vehicles that came with both sizes
- Mercedes-Benz SLC300 2017–2020
- Mercedes-Benz SLK350 2005–2010, 2012–2016
- Mercedes-Benz C250 2012–2016
- Mercedes-Benz SLK300 2009–2011, 2016
- Mercedes-Benz C350 2006–2015
- Mercedes-Benz SLK250 2012–2015
- Mercedes-Benz C300 2008–2014
- Mercedes-Benz CLK350 2006–2009
- Mercedes-Benz CLK550 2007–2009
- Mercedes-Benz SLK280 2006–2008
- Mercedes-Benz C230 2004–2007
- BMW 330Ci 2001–2006
Vehicles that use 225/45R17
Vehicles that use 245/40R17
See every alternate size for 225/45R17
Frequently asked questions
Can I use 245/40R17 instead of 225/45R17?
Usually, yes: 245/40R17 is within 3% of the overall diameter of 225/45R17 (−0.9%). Use wheels of the right size and width, match or exceed the original load index, and check clearance at full steering lock.
How much does the speedometer change between 225/45R17 and 245/40R17?
With 245/40R17 instead of 225/45R17, the speedometer shows 100 km/h when you are actually doing 99.1 km/h.
Which vehicles came with both 225/45R17 and 245/40R17?
Both sizes were original equipment, on different trims or packages, on the 2017–2020 Mercedes-Benz SLC300, 2005–2010, 2012–2016 Mercedes-Benz SLK350, 2012–2016 Mercedes-Benz C250, 2009–2011, 2016 Mercedes-Benz SLK300, 2006–2015 Mercedes-Benz C350, 2012–2015 Mercedes-Benz SLK250.