How fast can you drive on a spare tire?

The spare tire, popularly referred to as a donut spare tire, is now equipped with 93% of all cars produced in the world.

It is not intended for full use and serves only to get to the nearest workshop or tire fitting shop in case of a puncture of the main wheel.

But it must be done accordingly, as there are special recommendations for driving with a technological wheel. Drivers, whose cars are equipped with a dolly, need to know which axle to put it on, as well as how many miles and at what speed it can be driven.

What are the differences between a regular wheel and a spare tire?

There are several important differences between a donut spare tire and a full-size tire. The donut spare tire is always mounted on a special metal disc and is usually the same size or one inch smaller than the main wheels. This is because the manufacturer is trying to minimize its costs. The lineup of any car factory includes models with different size wheels and almost every model in the showroom you can order a larger wheel.

• Weight. A small wheel no doubt has less weight than a standard tire.
• Size. The size of the spare tire is much smaller than the parameters of the standard tire because its disc and rubber are narrower than that of a traditional spare.
• Price. Metal and rubber, which are used to create a standard car wheel, which is designed for long-lasting operation, is of higher quality. Whereas the production of a spare wheel is much cheaper for the manufacturer due to the use of conventional steel.
• Durability. Traditional rubber is designed for permanent use, so it is more reliable than a donut spare tire, which only helps to drive the car to the service station.
• Manufacturing quality. Due to the use of low-quality materials, the tread pattern of the spare tire wears more quickly.

How to drive on a spare tire

If you have a flat tire and need to put a donut spare tire, the first thing you need to analyze the situation. You can not put a spare tire on the drive axle, as immediately there will be a difference in angular velocities between the wheels, which is extremely detrimental to the differential. If there is a front drive, the ball supports, silent blocks of front suspension, and steering rack also suffer.

Therefore, if a wheel on a driving axle is deflated, it is recommended to change it for a complete one from another axle and put a spare wheel there.

Drivers of cars with permanent all-wheel drive are better to put a wheel on the axle, which has the maximum torque distribution.

How fast can I drive on a donut spare tire?

The proper speed designation on the spare wheel should be written on the side of the spare wheel or on the wheel itself on a large and conspicuous sticker.

If it is missing or illegible, the rule of thumb is not to drive faster than 50 mph with a donut spare tire.

Exceeding the speed limit can lead to tire failure, differential damage, or both. If possible, try to avoid highways. And go to a tire shop as soon as possible.

Since the contact, compared to a regular wheel, is much smaller, the car’s handling is significantly impaired and the braking distance increases.

On average, the braking distance of a car with a spare tire increases by 6 feet.

With a donut spare tire, electronic aids (such as ABS, ESP, or DSTC) start working incorrectly, as they take the smaller wheel diameter for slippage and begin to struggle with it actively. It is also not worth turning the steering wheel suddenly or changes lanes, like a wheel with a smaller tread contact area may simply not have time to grasp the road, and the car will start to drift forward, in the course of movement of the car. It is not recommended to tow a trailer with a spare tire installed on the car. Also, it is not allowed to drive using two donut spare tires at the same time.

The greater the difference in diameter between a regular wheel and a spare tire, the more difficult it is to drive.

If this difference is small and does not exceed 1 inch, you can drive quite well – the car will normally obey the steering wheel and the electronic systems will not cause much trouble.

If the difference is 2 or more inches, the electronic systems ABS, ESP, DSTC should be switched off, if possible. If this is not done, the wheels will be constantly blocked, as the computer will think that the grip ratio of the wheels is different, and will slow down one wheel, not allowing the car to drive normally. You can disable the system through the menu of the computer, most models provide such an opportunity. If this is not possible, you should gently and smoothly, without making sudden movements, try to drive to the tire fitting. If it is far away or trip is impossible because of too active interference of electronic helpers, it is better to continue further way on a tow-bar.

Driving on a spare tire

• Before driving on a spare tire, it is important to remember a few guidelines:
• Make sure your spare tire is properly inflated.
• Check your tire regularly for damage or punctures in the tread and sidewall.
• Watch your speed – follow your car and tire manufacturer’s instructions regarding your speed as well as the distance traveled.
• Remember that a spare tire (other than an appropriately sized spare tire) is a temporary solution that should only be used to get you safely to a service station.

Conclusion

If you act competently, you can get to a tire fitting without much trouble. The main thing is to move at a minimum speed, avoiding sudden acceleration, braking, and shifting from row to row unnecessarily, as well as to observe safety precautions. New drivers, as well as drivers going on a long journey, should better put a full-size spare in the trunk instead of a spare.