Tire management

Tire replacement forecast: how to calculate the timeframe

Luiz Felipe Luiz Felipe 4 min read
Tire replacement forecast: how to calculate the timeframe

Knowing the right time to replace your fleet's tires is essential to keep your operation's assets from going to waste. However, identifying the tire replacement forecast does not mean it is time to take the tire out of service and dispose of it.

It actually represents the ideal moment for the tire to be removed from the vehicle and sent to the retreading process — an action that contributes to increasing its useful life and reducing fleet costs.

What is more, replacing the tire at the right time helps prevent accidents and other safety risks on the road. That is why identifying the ideal moment to replace these assets is just as important as knowing how to take care of your fleet's tires.

Here is what you will see:

How to forecast tire replacement?

1 – Using the tire's TWI

The TWI, also known as the “Tread wear indicator”, is a marking at the bottom of each groove of the tire that indicates the moment when the tread is worn beyond its permitted and safe limit.

If you notice that the tread is getting close to this marking, even without taking a measurement in the most appropriate way (with a caliper or an electronic tread probe), you can already consider the tire replacement forecast to be very close.

2 – Keep track of tread depth

One of the most important activities in fleet tire management is keeping track of tread depth, which is done to find out at what pace tread wear takes place.

Measuring tread depth is a routine that can take place every two weeks or every month. After a few months, you will have enough data to understand the average depth loss of each tire model and to forecast how much time is still left until wear reaches its limit.

3 – Keep track of tire pressure

In tire control, calibration of these assets is an essential task. Without the correct pressure, the tire can suffer various kinds of damage, from irregular wear to a blowout on the road.

Although it does not play a major role in calculating the tire replacement forecast, it is one of the tire performance indicators that contributes to the tire's durability and also to its preservation, so that it can be retreaded without problems later on.

4 – Calculating the tire replacement forecast

What we do is use tire inspection to understand how much a tire wears from one month to the next, as we explained in the tread depth measurement process, and work out an average of how many months it would take to reach its set limit.

In Brazil, the limit set by law is 1.6 mm; however, letting wear go on until that point increases retread rejections and can fatigue the tire casings.

Generally, the limit set in heavy vehicle fleets is 3 mm, but it is something you can determine after analyzing the operating data of your own transport operation.

First, you need to identify the average tread depth loss per month:

Calculation of the average tread depth loss per month.

With this result in hand, you can calculate the tire replacement forecast:

Calculation of the tire replacement forecast.

Watch the video for 7 reasons to replace tires:

(video in Portuguese)

Why keep track of the tire replacement forecast?

Because it helps plan the operation's budgets allocated to tire management, giving a better view of the number of retreads that will take place in the month, as well as how many new tires should be purchased in the same period.

In addition to keeping track of the tire's useful life, you need to have control over when to replace it and the right time to send the asset on to the disposal stage.

How to collect the data for the tire replacement forecast?

A tire management system is essential to make it easier to collect and analyze data on the fleet's tires.

To do this, you should also use the electronic tread probe, a tire inspection tool that sends pressure and tread depth readings directly to your system over a Bluetooth connection.

In addition to being one of the main tools for reducing, and even eliminating, tire disposal in your operation, the system also increases the number of retread lives and generates fuel savings.

This has even been proven by some of Prolog's case studies, as you can see in our free downloadable material: Tire Management Case Studies You Need to Know (in Portuguese).

Frequently asked questions

What is the tire replacement forecast?

It is the estimate of the moment when the tire should come off the vehicle, and that moment is not the moment of disposal: it represents the ideal time to send the tire for retreading, which helps extend its useful life and reduce fleet costs. Replacing tires at the right time also helps prevent accidents and other safety risks on the road.

How do you calculate the tire replacement forecast?

Measure the tread depth at regular intervals and record how much tread the tire loses from one month to the next. After a few months, these records show the average monthly loss of each tire model, and it is from this average that you estimate how many months are still left until wear reaches the limit set by the operation.

What is the minimum tread depth for replacing a tire?

In Brazil, the limit set by law is 1.6 mm, but letting wear reach that floor increases retread rejections and can fatigue the tire casing. In heavy vehicle fleets, the value adopted is generally 3 mm, and each operation can set its own after analyzing its own operating data.

How often should tread depth be measured?

Measurement can become part of the routine every two weeks or every month. After a few months of accumulated records, it is possible to know how much depth each tire model loses on average per month and to project how much time is left until wear reaches the adopted limit. The TWI, a marking at the bottom of each groove, helps show when the tread is already close to the permitted limit.

How do you collect the data for the tire replacement forecast?

A tire management system makes it easier to collect and analyze fleet data, and the electronic tread probe is the inspection tool that sends pressure and tread depth readings straight to that system over a Bluetooth connection. With these records gathered, the system is regarded as one of the main tools for reducing tire disposal and increasing the number of retread lives.

Why keep track of the tire replacement forecast?

Because it provides a basis for planning the budget allocated to tire management: it becomes easier to see how many retreads should take place in the month and how many new tires need to be purchased in the same period. In addition to keeping track of useful life, it is necessary to know when to replace the tire and at what point it should go to disposal.

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