Here we want to emphasize important facts, regarding performance and safety, when you do a tire replacement.
IMPORTANT! When doing the tire replacement, first information sources you should refer to are the vehicle tire placard and vehicle owner’s manual. These sources contain information such as Original Equipment(OE) tire size designations, together with recommended tire inflation pressures. The vehicle tire placard is usually placed inside a glove box, on a door edge or a door post.
It's not always possible to acquire the same tire size as the OE tire size for a replacement tire.
Thus, to ensure original tire and vehicle performances devised by a vehicle manufacturer, the replacement tire should have the same or similar features as the original equipment(OE) or stock tire:
- the same tire size as the OE tire, or the tire size with allowed deviation in the overall tire diameter, compared to the OE tire;
- the same load-carrying capacity(load index or load range) as the OE tire, or greater than the original tire;
- the same inflation pressure capability as the OE tire or greater than the operating inflation pressure of the OE tire, which can be found on the vehicle's tire information placard;
- the same speed rating(speed symbol or speed index) or higher than the original tire;
- to have the same construction as the OE tire, radial or bias-ply.
There are multiple reasons why vehicle owners may require the installation of a tire size that is not the same as the OE tire size, fitted by the vehicle manufacturer. Possible reasons for the tire replacement could be:
- Plus Sizing – enlarged wheels/rims give more attractive look to a car. Also, may improve handling performance, but may result in a less comfortable ride; the substitute tires - and their wheels - may also be more susceptible to damage by impact with potholes, road hazards, and other objects such as curbs;
- Speed Rating changes;
- Passenger Tire vs. Light Truck Tire fitments;
- P-Metric vs. Euro-Metric;
- Standard Load(SL) vs. Extra-Load(XL) or Reinforced fitments;
- A combination of items, including those mentioned above.
The following are additional guidelines, following aforementioned, but both groups are only general guidelines for the tire replacement, including substitute tire sizes, with a goal to promote users education and safety:
- Always refer to and follow the vehicle manufacturer's replacement tire recommendations.
- In some cases, a vehicle manufacturer may specifically advise against the application of replacement tires that are not the original size or type. Always follow these recommendations.
- Substitute tires should never be inflated below the pressure shown on the vehicle tire placard.
- Never exceed the maximum load capacity and/or inflation pressure listed on the sidewall of the tire. Follow the vehicle tire placard information.
- Never exceed the maximum load capacity and/or inflation pressure of the wheel.
- Never utilize an unapproved wheel or one that does not meet the approved rim width range for the selected tire size. For the approved tyre/rim combinations, consult the current Tire Standards Manual(TRA, ETRTO,…) or you can use, as a starting point, our website Rim width for tire size chart/calculator.
- The overall tire diameter of replacement tires should be within vehicle manufacturer tolerances. If tolerances are not provided, you can use our Tire size comparison calculator as a starting point.
- Acceptable load capacity and/or overall tire diameter do not imply acceptable vehicle clearance. Body and chassis clearance must be checked on the vehicle's front and rear axles.
- It's recommended that all tires on a vehicle have the same size, construction(radial, non-radial) and speed rating. If tires have different speed ratings, a tire with the lowest speed rating limits tire-related vehicle’s speed;
- Always check that the diameter value for both, tire and rim/wheel, are the same. E.g., for the tire designation 195/65R15, the tire must be mounted on the 15” rim/wheel;
- If You have any doubts how to handle a problem regarding tire to rim fitment, consult your vehicle manufacturer, tire manufacturer or tire specialist.
- Read about importance of a tyre pressure.
- Winter tire pressure check - find out why is important to set higher tire pressure, when a car is in the garage.
- Tyre pressure during summer - when is the best time of the day to check tyre pressure?
- See Tire pressure conversion charts - bar to psi, psi to bar