Tyre size 245/40 R18
Find 245/40 R18 Tyres
Free guidance for 245/40 R18 tyres. Performance saloons. Always confirm fitment on your tyre sidewall.
Tyre Size Checker
Enter a UK tyre size such as 205/55 R16 91V to decode the width, profile, rim, load index and speed rating.
Find your tyre size on the sidewall, the driver's door frame, fuel flap or vehicle handbook.
- This tyre size may be incomplete. A full tyre size often looks like 205/55 R16 91V. Check your tyre sidewall for the load index and speed rating.
What 245/40 R18 means
245 is the section width in millimetres. 40 is the profile (sidewall height as a percentage of the width). R is radial construction. 18 is the wheel rim diameter in inches.
A full tyre size also includes a load index and speed rating, e.g. 245/40 R18 91V. The load index maps to a maximum weight per tyre, and the speed rating maps to a maximum speed at full load.
Where 245/40 R18 is commonly fitted
Performance saloons.
Even when a tyre size is common, the specific tyre that's right for your vehicle depends on the load index, speed rating, and sometimes whether the original equipment is run-flat or EV-rated. Always confirm with your tyre sidewall, vehicle handbook or a qualified UK tyre fitter before fitting.
Get tailored guidance for this tyre size
Free UK Tyre Finder
Takes about 30 secondsHow would you like to start?
You can find this on your tyre sidewall.
This tyre size may be incomplete. A full tyre size often looks like 205/55 R16 91V. Check your tyre sidewall for the load index and speed rating.
Step 1 of 7 — Start
What to check before fitting
- Confirm the size on your tyre sidewall
- Match or exceed the original load index and speed rating
- Check the EU tyre label for wet grip, fuel and noise
- Pick the right type — summer, all-season or winter
- Fit as a full set or at least a matched pair on the same axle
Frequently asked questions
Quick answers about UK tyre fitment, MOT rules and seasonal options.
Does fitting 245/40 R18 affect my insurance?
If 245/40 R18 is the original size for your car, fitting it doesn't affect insurance. If you're switching from the OEM size to 245/40 R18, you may need to declare it — particularly if it's a wider or larger-rim option.
Can I fit a different size to 245/40 R18?
Only fit a size approved for your specific car. Changing width, profile, rim, load or speed rating affects handling, braking, fuel economy and MOT. Approved alternatives are usually listed in the vehicle handbook.
Is 245/40 R18 available as a winter tyre?
Most UK fitments — including 245/40 R18 — are produced as winter tyres by Continental, Michelin, Bridgestone, Pirelli, Goodyear and others. Winter tyres are stamped with the 3PMSF symbol and stay flexible below 7°C.
What do EU tyre labels show for 245/40 R18?
Every new tyre — including 245/40 R18 — carries an EU label rating fuel efficiency, wet grip and external noise. For UK driving, prioritise wet grip first.
What load index do I need with 245/40 R18?
Load index is on the placard inside your driver's door frame. 245/40 R18 can be ordered in different load indices (e.g. 91, 94, XL/RF) — match or exceed the original specification for your car.
Tyre sizes related to 245/40 R18
Same rim, similar width or profile — common alternatives UK drivers compare with 245/40 R18.
Tyre Finder UK provides general tyre guidance only. We do not guarantee tyre fitment, local stock, prices or fitting availability. Always confirm your tyre size, load rating, speed rating and vehicle requirements using your current tyre sidewall, vehicle handbook, manufacturer guidance or a qualified tyre fitter before fitting.