Spare Tire Size Calculator

Spare tire size should match regular tires for consistent handling. Full-size spares are ideal, while donut spares are for temporary, slower driving. Donut spares typically have a max speed of around 50 mph and are not recommended for long distances. Always consult your owner’s manual for exact specifications and guidelines.

Tire Size	Compatibility	Recommended Use	Maximum Speed	Long-Distance Use	Notes
Full-Size	Matching regular tires	Yes	Same as regular tires	Yes	Provides consistent handling and performance.
Donut Spare	Smaller than regular tires	Temporary use	Typically 50 mph	Not recommended for long distances	Designed for space-saving and short-term emergencies.
Space-Saver Spare	Smaller than regular tires	Temporary use	Typically 50 mph	Not recommended for long distances	Space-saving design similar to donut spare.
Run-Flat Tire	Matching regular tires	Yes	Manufacturer-specific	Yes	Designed to be driven for short distances with a flat tire. May not fit all vehicles.

FAQs

What size should my spare tire be? The size of your spare tire should match the size of your car’s regular tires.

Does your spare tire need to be the same size? Ideally, your spare tire should be the same size as your regular tires to ensure proper handling and performance. However, a smaller “donut” spare can be used temporarily.

How do I know what spare tire will fit my car? Check your car’s owner’s manual or the information on the driver’s side door jamb for the recommended spare tire size. You can also consult with a tire professional for guidance.

Can you keep a full-size spare tire? Yes, you can keep a full-size spare tire, which is a good option for maintaining consistent handling and performance.

Can you use a 17-inch spare with 18-inch wheels? Using a 17-inch spare with 18-inch wheels is not recommended for extended periods, but it can be used temporarily in emergencies.

Why is my spare tire the wrong size? A spare tire may be the wrong size due to a manufacturer’s choice or previous owner’s decision. It’s important to ensure the correct spare size for your safety.

Can I drive with a smaller spare tire? You can drive with a smaller spare tire temporarily, but it may affect handling and speed capabilities. Try to replace it with the correct size as soon as possible.

Is a 10-year-old spare tire still good? A 10-year-old spare tire may still hold air, but its structural integrity and rubber compound may have deteriorated. It’s recommended to replace it if it’s that old.

How long can you drive on a regular-sized spare tire? A regular-sized spare tire can be driven on until the tread wears out, but it’s not designed for long-term use. Replace it with a matching tire as soon as possible.

Does a spare wheel have to be the same size as the other wheels? Ideally, a spare wheel should be the same size as the other wheels for consistent performance. However, a temporary spare can be smaller.

Can you drive on the freeway with a spare tire? You can drive on the freeway with a spare tire, but it’s best to limit highway speeds and replace it with a regular tire as soon as possible.

Is a donut spare better than a full-size spare? A full-size spare is generally better for consistent handling and performance. Donut spares are meant for short-term use in emergencies.

Is there a difference between a spare tire and a donut? Yes, there is a difference. A spare tire can be a full-size replacement, while a “donut” or compact spare is smaller and intended for temporary use.

Can I use a 16-inch spare for 17-inch tires? Using a 16-inch spare for 17-inch tires temporarily is possible but not recommended for extended use.

Can I use an 18-inch spare with 19-inch tires? Using an 18-inch spare with 19-inch tires is not ideal but can be used temporarily in emergencies.

Can you put an 18-inch tire on a 16-inch rim? No, you cannot put an 18-inch tire on a 16-inch rim as the sizes must match for safety and proper fit.

What are the disadvantages of a full-size spare tire? Disadvantages of a full-size spare include its weight, taking up more space, and potentially higher cost compared to compact spares.

How much smaller can a spare tire be? A spare tire can be smaller but should be within a few inches in diameter to maintain safe handling and clearance.

What happens if you drive too far on a spare tire? Driving too far on a spare tire can cause it to wear quickly, potentially leading to a blowout or loss of control. It’s meant for short distances.

How fast can you go on a donut tire? Donut spare tires are typically rated for speeds up to 50 mph, but it’s best to consult your specific tire’s guidelines.

Can you drive more than 70 miles on a spare? While you can drive more than 70 miles on a spare in an emergency, it’s recommended to replace it as soon as possible.

Why is my spare tire smaller than my regular tires? Spare tires are often smaller (donut spares) to save space and weight in the vehicle, making them less suitable for extended driving.

Can I use a 15-year-old spare tire? A 15-year-old spare tire is likely too old for safe use and should be replaced.

Can a 20-year-old tire still be good? A 20-year-old tire is generally not safe for use due to rubber degradation over time.

Can I reuse a spare tire? Spare tires can be reused if they are in good condition and have not been extensively used or damaged.

Can I drive on a spare tire for 3 days? You can drive on a spare tire for a few days, but it’s essential to replace it with a regular tire as soon as possible.

Can I drive 250 miles on a spare tire? You can drive 250 miles on a spare tire in an emergency, but it’s not designed for long-distance use.

Can I use a spare tire for 2 days? Using a spare tire for 2 days is acceptable for short-term use, but it should be replaced with a regular tire as soon as possible.

Can you drive over 50 mph on a spare? Most spare tires, especially donut spares, are not designed for speeds over 50 mph.

Can you drive long distance on a spare wheel? Driving long distances on a spare wheel is not recommended; it’s intended for short-term use to reach a repair shop.

Can you drive 55 mph on a spare tire? Some spare tires are rated for 55 mph, but it’s crucial to check the manufacturer’s recommendations.

What is the perfect size donut? The perfect size for a donut spare depends on your vehicle’s specifications. Consult your owner’s manual for the correct size.

Is it better to have a spare donut tire on the front or rear of a front-wheel-drive vehicle? A spare donut tire is typically placed on the front of a front-wheel-drive vehicle to maintain better control and steering.

Is it worth it to buy a spare tire? Having a spare tire is essential for safety and convenience, especially in emergencies, so it’s generally worth the investment.

What are the four types of spare tires? The four main types of spare tires are full-size spares, donut spares, space-saver spares, and run-flat tires.

Will a spare donut fit any car? Donut spares are not universal and may not fit every car. They should match the specifications of your vehicle.

Why are 19-inch wheels better than 18-inch? 19-inch wheels may offer improved handling and a sportier appearance, but the choice depends on personal preference and vehicle compatibility.

Can you drive on 18-year-old tires? Tires that are 18 years old are well beyond their safe usability and should be replaced.

Can I change tire size without changing rims? You can change tire size without changing rims if the new tires are compatible with the existing rims and maintain proper clearance.

What is the difference between 16-inch and 18-inch wheels? The main difference is the size; 18-inch wheels are larger than 16-inch wheels. This can affect handling and appearance.

What tires fit on an 18-inch rim? Tires for an 18-inch rim should match the rim size and be compatible with the vehicle’s specifications. Consult your owner’s manual for guidance.