245/40R18 Tire Size Specifications
This tire size 245/40R18 fits 15 vehicles in our database.
Everything to know about the 245/40R18 tire size
Size geometry
A 245/40R18 tire has a 245mm section width and a 40% aspect ratio, mounted on a 18-inch rim. Sidewall height works out to 98.0mm (3.86") and overall outside diameter is 653.2mm (25.72"). At highway speed the tire completes about 487 revolutions per kilometre â your speedometer and odometer were calibrated against this number.
Direct substitute sizes
If 245/40R18 is unavailable, the closest same-diameter substitutes on the same rim are 235/42R18 and 255/38R18. Both keep your speedometer reading within 1% â safe for daily use, ABS, and stability control. Always verify load and speed ratings before swapping.
Plus / minus sizing options
For a 245/40R18 you can upsize to 255/33R19 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 235/47R17 (minus-one) for a softer ride or winter setup. Both stay inside the Âą3% diameter tolerance that ABS and TPMS systems expect.
Vehicle compatibility
15 vehicles in our database run the 245/40R18 tire size from the factory. Aftermarket fitment depends on rim width, offset, and clearance â match these specs to your wheel before purchasing tires.
Vehicles Using 245/40R18
Alpine A110
Years: 2019 - 2026
Audi A4
Years: 2008 - 2026
Audi A5
Years: 2007 - 2016
Audi S4
Years: 2009 - 2026
Audi TT
Years: 2014 - 2023
BMW M3
Years: 2007 - 2013
BMW M5
Years: 1998 - 2003
Cadillac CTS
Years: 2014 - 2019
Chevrolet Corvette
Years: 2005 - 2013
Donkervoort D8 GTO
Years: 2013 - 2026
Mercedes-Benz C-Class
Years: 2015 - 2026
Mercedes-Benz CLS
Years: 2005 - 2010
Mercedes-Benz E-Class
Years: 2010 - 2016
Mitsubishi Lancer
Years: 2008 - 2017
Subaru WRX
Years: 2015 - 2026