California bill aims to increase tire efficiency, experts say it's unrealistic

SAN ANTONIO—Newly introduced California legislation looks to elevate the environmental performance of replacement tires sold in the state. But the proposal, as it stands, has the potential to significantly impact the North American tire industry by setting standards that some say could be unrealistic.

In February, pursuant to Assembly Bill 844, California introduced proposed rules intended to ensure the efficiency of vehicles in the state and empower consumers to make more informed decisions about their replacement tire purchases.

To help consumers better understand the roles their tires play in extending range and bettering fuel economy, the proposal includes a five-star tire rating system and consumer educational program that targets points of sale and online resources.

But the law goes further.

It also looks to raise the bar for the tire industry by setting maximum fuel/range efficiency standards for replacement tires, and the proposed rules do so with rolling resistance as the key indicator.

"At its heart, (AB 844) aims to raise the energy efficiency of replacement tires in California to be equal to original equipment tires," Sebastian Serrato, a representative for the California Energy Commission (CEC) told Smithers Traction Summit attendees. "So this helps with the issue that often happens when consumers purchase replacement tires, they literally end up with tires that are significantly less efficient than (those) the vehicle came with when new."

For the U.S. Tire Manufacturers Association and its member companies, the proposal is concerning, Tracey Norberg, USTMA senior vice president and general counsel, said in a presentation immediately following Serrato's. Among those concerns is the leveled expectations for OE and replacement tire attributes.

"That law focuses on trying to make replacement tires like OE tires, which for people who just care about fuel economy, maybe that sounds good," Norberg said. "But for people who recognize the advanced benefits of replacement tires, not so much."

USTMA contends that there are key, essential differences between OE tires—that are designed to maximize the performance of a specific vehicle model—and replacement tires, which need to demonstrate performance characteristics that suit a broad range of vehicle makes and models as well as varying customer expectations.

Additionally, there are tradeoffs among tire performance attributes, and that includes the relationship between treadwear and rolling resistance. OE tires, for instance, may have a lower rolling resistance, but they also aren't built to last as long as replacement tires. OE tread life expectations are lower than replacement tires', and OE tires do not come with tread life warranties.

At present, California's proposed legislation is focused on establishing a five-star rating system for replacement tires, which is intended to help inform consumer decisions. Tires would be awarded anywhere from one to five stars for efficiency, depending on the rolling resistance coefficient for each model, Serrato said.

Proposed framework for the rating system is:

• 5 stars—RRC less than or equal to 6.5 N/kN
• 4 stars—RRC from 6.6 to 7.7 N/kN
• 3 stars—RRC from 7.8 to 9.0 N/kN
• 2 stars—RRC 9.1 to 10.5 N/kN
• 1 star—RRC equal to or greater than 10.6 N/kN

The rating system has further importance because it essentially serves as the guideline for the state's phased-in minimum RRC performance standards—9 N/kN beginning Jan. 1, 2026 and 7 N/kN beginning Jan. 1, 2028.

So the law, if passed as proposed, would eliminate the sale of one- and two-star-rated tires by 2026, and then further eliminate the sale of three-star and some four-star-rated tires two years later.

But how many tires fall into those categories California is proposing to eliminate?

"This would, really, eliminate most of the tires currently on the market," Norberg said.

According to data compiled by USTMA, a large majority of replacement tires have RRCs between 8.5 N/kN and 10 N/kN.

But when the RRC is aligned with two data sets—the EU virtual lab and Smithers—the impacts of the California proposal are even more "severe," she said.

Assuming the CEC proposal stands as is, and using EU virtual lab as a guide, more than 56 percent of tires currently on the market could not be sold in California by 2026, according to USTMA estimates. More than 97 percent of tires currently sold in California would not meet the 2028 minimum proposed threshold for RRC.

When compliance margins are factored in, USTMA said the percentage of tires on the market today that potentially could not be sold in California jumps to 73 percent in 2026 and more than 99 percent in 2028.

When aligned with Smithers, USTMA estimates that the current CEC proposal would eliminate the sale of 70-80 percent of tires on the market today by 2026 and more than 99 percent by 2028. When compliance margins are factored in, those numbers climb to 90 percent in 2026 and 100 percent by 2028.

"This shows you," Norberg said, "the severity of the proposal."

California, however, sees stringent guidelines as necessary, namely because of the environmental benefits. Lower rolling resistance tires could reduce greenhouse gas emissions by more than 1 million metric tons per year, and do so in a way that is affordable to consumers.

"California light duty vehicles travel over 30 million miles each year and do so against the rolling resistance of four tires," Serrato said. "The energy used to counter the long-distance force must be provided through a system of motor, engine and drivetrain, which amplifies the energy losses in tires. This means the rolling resistance is a large driver to reduce in the state."

Norberg emphasized that USTMA is not against regulations that challenge the industry in the areas of sustainability and safety. But those regulations and standards, she said, need to be realistic. That's why the association takes a proactive approach, working with legislators at both state and federal levels.

"We do support minimum standards," Norberg said, "just standards that work for the industry from the point of view of innovation and product development timelines. As we are looking at minimum standards, they need to take into account consumer needs—being able to offer the tires that consumers are still looking for."

AB 844 has roots in a law passed in California in 2003. That law essentially directed the state to focus on tire efficiency regulations through an established rating system and minimum performance standards.

That's where AB 844 comes in 20 years later, emerging after efforts to establish tire efficiency regulations at the federal level either fell through or became stagnant.

The California Energy Commission was directed in November 2020 to investigate tire efficiency for what would become the current AB 844 proposal. It held public workshops three months later.

From there, CEC engaged in conversations with and obtained additional information from USTMA and California tire dealers as well as governing bodies in Canada and the European Union, among others.

CEC later worked with Smithers to collect some independent tire efficiency data for 149 tire models sold in the state. According to Serrato, three of each model were tested for rolling resistance and one of each for wet traction.

"Just to put it briefly," Serrato said, "we selected tires representing the three groups to meet the mandates of AB 844 and have a representative sample of tires that fit vehicles registered in California. The three groups are: replacement tires, original equipment tires and efficient tires as marketed by manufacturers.

"Tire efficiency and wet grip were laboratory-tested. However, information about the UTQG ratings and other tire characteristics were taken from the tire sidewalls when they were procured."

The use of UTQG to determine the treadwear data for the regulation may not be the most accurate way to go, Norberg said. She pointed instead to actual consumer data on treadwear that was provided by Discount Tire. It showed the actual median mileage consumers got from their replacement tires.

"Tires that were rated anywhere from 200 on UTQG all the way up to 800 kind of performed similarly," Norberg said. "And it really shows that the UTQG grade is not an indicator or differentiator of how a tire would perform in terms of treadwear expectation."

California, Serrato said, does intend to do some additional testing, and treadwear is likely to be included in those tests.

For now, though, CEC is proceeding with data from its commissioned independent testing and feedback it continues to gather from discussions with the public, regulators and tire industry stakeholders.

According to Serrato, AB 844—introduced in February 2023—has five key objectives:

• Establish a database of the energy efficiency that represents a sample of replacement tires sold in the state. (This is to be based on test procedures adopted by the commission.)
• Establish a rating system that will allow consumers to make more informed decisions.
• Establish requirements that manufacturers report the energy efficiency of replacement tires.
• Develop and adopt a minimum efficiency standard for replacement tires.
• Establish a program that will allow consumers to make more informed decisions when purchasing tires for their vehicles.

California still is working on tailoring its tire efficiency legislation, and it is in the process of gathering feedback—from all stakeholders. And as it does, USTMA plans to be there to provide insights, offer ideas and identify areas of concern.

The state is focused on regulating tires for passenger vehicles. To do this, it's applying AB 844 standards to all passenger and light truck tires. And while it is true that some light truck tires often are used for fitments on larger passenger vehicles, not all LT tires fit this description, according to Norberg.

"Right now, their proposal includes passenger tires and LT tires, which—as those of you who are familiar with the industry know—is a little broader than just tires for passenger cars and light trucks," Norberg said. "As we go through this, they are talking about regulating both passenger tires and LT tires."

That point, she said, needs to be clarified—especially when it comes to consumer information.

"So making the distinction between passenger tires that go on consumer vehicles and LT tires that go on mostly commercial vehicles," Norberg said. "We are really focused on those passenger tires and those outfitted on the types of light trucks that consumers typically purchase."

When it comes to informing consumers about their replacement tire purchases, USTMA advocates for clear, concise consumer education programs that leverage online resources and point-of-sale opportunities to help ensure the right fit for vehicles, consumers and the environment.

California is attempting to do that with its five-star rating system, consumer information program and an online database that can easily compare tire models' performance attributes such as rolling resistance and treadwear expectations.

USTMA is working with California as it moves forward with fine-tuning its AB 844 proposal, and the association is encouraging a more concise and positive approach to the ratings.

"We would like, ideally, for the ratings to be something that doesn't indicate a negative performance for a lower-rated tire," Norberg said, noting USTMA prefers the "good, better, best" approach. "We talked about a medals approach where it is bronze, silver, gold. And the medals approach also gives the opportunity to add a higher performing category—a platinum or a titanium—as performance improves."

CEC has identified some exemptions to AB 844, and Serrato noted that additional exemptions could be added as the needs arise. Current exemptions include:

• Low volume tires (less than 15,000 units produced annually);
• Deep tread, winter snow tires;
• Space saver tires for temporary use as a spare;
• 12-inch-rim or smaller fitments;
• Motorcycle tires; and
• OTR tires for recreational vehicles.

"We agree with the exclusions that are in the current California legislation," Norberg said. "We also have identified competition tires that we believe also should be excluded.

"And, with winter tires… because we are trying to advocate for a unified North American approach, we would like it to be allowable for winter tires to be graded or rated in U.S. programs to allow for consistent marketing materials across North America."

According to Serrato, final legislation only will be approved with the understanding that performance standards implemented must also align with the following considerations:

• Standards must be technically feasible and cost effective.
• Standards should not adversely affect tire safety.
• Standards should not adversely affect the average tire life of replacement tires.
• Standards should not adversely impact state efforts to manufacture scrap tires.

As it stands, Serrato said, CEC believes that the standards—including minimum RRC requirements—achieve all of the aims.

"These proposed standards are not expected to shorten the tire life or impact the used or waste tire market in any (significant) way," Serrato said.

USTMA disagrees. Particularly when it comes to the minimum RRC standards, which to date, have not been consistently demonstrated in the replacement tire market.

And it is working to help California legislators understand why.

"From our perspective, we think regulators need to create regulation that is challenging in that it can move the industry forward, while keeping the industry in an economically solvent and beneficial position," Norberg said. "Regulations really need to be created in such a way that it fosters the development of new technologies and allows for those improvements to be made."