The ‘TPMS’ regulation UN ECE R141 came into effect on 6 July 2022 with the aim to improve road safety. In addition to Tyre Pressure Monitoring Systems (TPMS), the regulation also includes TPRS (Tyre Pressure Refill Systems) and CTIS (Central Tyre Inflation Systems).
For end users, transport companies and fleets, the new regulation will come into effect on 7 July 2024 on every new trailer, meaning every new trailer needs to have some form of ‘TPMS’ installed during registration of the vehicle.
Celerity DRS General Manager, Andre Gerken, said this hasn’t been clearly communicated to the market.
“Not everyone in the industry has knowledge of the legislation and the resulting measures,” he said. “Our aim is to provide more information about the different solutions that are available.”
TPMS typically performs a function to evaluate inflation pressure of the tyre or the variation of inflation pressure over time and to transmit corresponding information to the heavy vehicle driver/user during operation.
In terms of functionality and performance, there are two types of TPMS, direct and indirect.
A direct TPMS is using an additional pressure sensor, installed inside the wheel or on the tyre valve, and an indirect TPMS is using the existing EBS/ABS sensors to determine the status of the tyre pressure. Currently, according to Gerken, there are no indirect TPMS options for commercial vehicle trailers available.
One of the key advantages of a TPMS is being informed immediately about a pressure change in the tyre. This allows the driver to adjust the optimum tyre pressure to reduce tyre wear and fuel consumption. “But a TPMS still requires a human intervention to ensure the right tyre pressure,” said Gerken.
The battery life of a TPMS sensor depends on the data transmission interval and the data size. The information provided by the TPMS manufacturer on the lifetime of sensors varies from up to three to 10 years. “The majority of available sensors cannot be recharged so far and need to be replaced, if the battery is empty,” he said. “Depending on the fleet size, this could be hundreds of sensors per year, which is not positive from an ecological point of view.”
For an optimal working TPMS, the radio performance of the individual sensors is important, particularly for special vehicles such as B tank trailers or in-loaders.
In these vehicles, the high amount of metal parts can disturb the communication, which could lead to connection failures.” Connectivity is also an important consideration.
“Certain TPMS allow an integration in existing telematic devices,” said Gerken. On one hand this helps to inform the Backoffice about the tyre status and it allows to register tyre issues and records when a tyre is below an accepted pressure.
On the other hand the driver can be held more responsible, if a damage occurs despite an in-built TPMS, because he was informed about a pressure loss in advance.
While the up-front investment into these systems is what has kept many fleets from adopting, fleets will find that the added costs result in an overall operating savings that provides a highly desirable return on investment.
Here, the TPRS scores with low follow-up costs and the advantage that human intervention is reduced to a minimum. With a TPMS, if the driver does not respond to a warning, it can still cause a problem as the tire is not being re-inflated.”
“Due to the R141, fleets need to have a system installed, therefore I expect that they will choose the system which will bring them the most benefit,” said Gerken. “Maybe at the beginning the cheapest option will be chosen, but at the end the benefits are important.
TPRS presents an opportunity for fleets to invest in better road safety measures compared to TPMS.
“There are already several fleets that are convinced of the benefits of TPRS,” said Gerken. “We even have customers using both systems, combining the benefits of TPRS and TPMS. For this reason, in addition to a standard TPRS-R141 solution, we are also working a stand-alone TPMS solution.”
Ultimately, whether it’s TPRS or TPMS, it is better than having no system installed.
“Active tyre pressure monitoring informs the driver and, if necessary, the fleet manager of a loss of pressure at the tyre,” said Gerken. “With this information, countermeasures can be initiated immediately i.e. to avoid a complete loss of the tyre and related failures. Without a system, it is almost impossible for a driver to detect a loss of tyre pressure while driving. This is also the reason why we regularly see vehicles with blow-outs parked on the side of the road. The early information can also reduce downtime. It is easier, faster and safer to repair/replace a tyre in a workshop than at a rest area or even at a hard shoulder. Every prevented blowout also helps to ensure that other road users are not hindered or even injured by tyre parts.”
So, what do manufacturers and fleets need to do right now to prepare for this regulation?
“Vehicle manufacturers should check to what extent TPRS and TPMS are already being used and how the production is prepared for it,” said Gerken. “Depending on the system, there are various installation and initial operation steps that have to take into account in the production process.
“In addition, it must be checked whether current orders are already affected by the R141.
If the delivery of the vehicle falls after the date when the R141 goes into force, a system needs to be installed.
“I would recommend fleets that have not yet dealt with the topic of tyre control systems, to start with it. It makes sense to identify the right system in advance so that you don’t encounter any bad surprises afterwards.
“For manufacturers and fleets it’s important that all involved employees (production, sales, drivers, workshop managers) are trained upfront on how to use the system in order to ensure a smooth process.”
In terms of regulation compliance, there are some challenges ahead.
“The advantage for the vehicle manufacturer is that system providers can have their system pre tested from test authorities. The test reports ensure that the system meets the requirements of R141 and will ease the homologation process.”
What is a TPMS?
A TPMS or Tyre Pressure Monitoring System is a system fitted on a vehicle, able to perform a function to evaluate the inflation pressure of the tyre or the variation of this inflation pressure over time and to transmit corresponding information to the user while the vehicle is in operation.
What is a TPRS?
A TPRS or Tyre Pressure Refill System is a system fitted on a vehicle, which can refill underinflated tyres fitted to an axle of the vehicle with air pressure from a vehicle mounted reservoir (infrastructure) while the vehicle is running but not limited to.
What to do when a leaking tyre is detected with TPMS?
Find a suitable place to stop, check and refill the tyre. If required, reset the TPMS and see how the tyre responds. If the response is positive, the driver could continue their journey, keeping close attention to the refilled tyre. If the tyre is emptying too quickly (20 per cent less or lower versus the required tyre pressure), stop immediately and take the appropriate action (replacing the tyre or receiving help). Continuing the journey without taking the necessary action would be strongly advised against.
Why should I invest in a TPRS as opposed to a TPMS?
A TPRS will help you to maintain the correct tyre pressure whilst the vehicle is stationary or in transit. In case of a pressure loss in a tyre the system will automatically start refilling the tyre to the pre-set level and informs the driver accordingly. The human intervention is reduced to a minimum. Instead, a TPMS will only inform you about the pressure loss in a tyre. Without human intervention the vehicle will continue its journey with a wrong tyre pressure. The benefits of an TPRS against TPMS are higher uptime, longer tyre life and lower fuel consumption.