released on August 2009

With the release of the world’s first commercial hybrid vehicle, the Prius, in 1997, Toyota showed consumers it possesses the most advanced environmental technology. However, the foundations of this technology were laid out as far back as the late 1960s and throughout the 1970s when Toyota overcame the tribulations arising from vehicle emission problems.

In 1968, Japan enacted the “Air Pollution Control Act,” which required levels of CO (carbon monoxide) in vehicle emissions to be reduced to 3% or lower. In the United States, the “Clean Air Act of 1970” (also called the “Muskie Act”) required the harmful substances HC (hydrocarbons), CO and NOx (nitrogen oxides) in vehicle emissions to be reduced by more than 90% of the previous regulatory limit.

Facing these new regulations, Toyota recognized the issue of environmental pollution as the most serious social issue facing the automotive industry in the1970s and undertook efforts to further strengthen its system for technological development. In 1971, in addition to building the Higashi-Fuji Technical Center, it rapidly increased the number of employees involved in vehicle emissions and simultaneously enhanced the Engineering Division at the company headquarters.

  • page01_photo1_tcm322-208111

    Working on measures to lower emissions (1975)

  • page01_photo2_tcm322-208121

    Toyota engineers study methods to prevent air pollution (1969)

In order to address the problem of simultaneously reducing CO, HC and NOx, Toyota set up an “emissions integration meeting” to utilize the combined technological capabilities of such companies as Hino Motors, Ltd., Daihatsu Motor Co., Ltd., Toyota Central Research & Development Laboratories., Inc. and Denso Corporation. Realizing they needed to look beyond Toyota’s accumulated know-how, the Toyota engineering team explored various possibilities before finally deciding that a catalytic method would play a key role in its development policy.

In January 1974, Japan’s Environment Agency announced the “1975 Vehicle Emissions Regulation.” Because the enactment of the “Muskie Act” had been postponed, this became the most stringent emissions regulation in the world. At this point, Toyota had decided to adopt both the Compound Vortex Controlled Combustion (CVCC) method and the catalytic method for the best results. The combined result was given the name “Toyota Total Clean System,” and Toyota promoted its efforts with a “compound thought” marketing campaign.

Then in December 1976, Japan’s Environment Agency announced the “1978 Vehicle Emissions Regulation,” which set an even stricter limit on NOx levels at 0.25g per 1km. The Toyota engineering team addressed this new standard with the three-way catalytic converter. By making various methods commercially viable, Toyota implemented measures to address the “1978 Vehicle Emissions Regulation” using optimal methods for each of its vehicle models and succeeded not only in reducing emissions levels, but also in its pursuit of a satisfactory total balance that included fuel efficiency, performance and price.

The measures that Toyota undertook to deal with the regulation of emissions were the result of a long and arduous succession of hard work and the combination of the comprehensive capabilities of the group. Toyota’s current level of environmental technology — the highest in the world — is based on the variety of technological know-how it has accumulated through this process.

  • page01_photo3_tcm322-208180

    Press conference on Toyota vehicles in compliance with the “1975 Vehicle Emissions Regulation” (1975)

  • page01_photo4_tcm322-208260

    A 1975 print advertisement for the “compound thought” campaign explains how the “Toyota Total Clean System” was achieved by looking at the emissions problem from various viewpoints.

— End —