Toyota TTC stands for Toyota Total Clean System, a moniker used in Japan to identify vehicles built with emission control technology. The technology was installed so that their vehicles would be in compliance with Japanese Government emission regulations passed in 1968. The term was first introduced in Japan, with an externally mounted badge on the trunk of vehicles equipped. The technology first appeared in January 1975 on the

Toyota Crown The is an automobile which has been produced by Toyota in Japan since 1955. It is primarily a line of mid-size luxury cars that is marketed as an upmarket offering in the Toyota lineup. Introduced in 1955 as the Toyopet Crown, it has served ...

, the

Toyota Corona Mark II The is a compact, later mid-size sedan manufactured and marketed in Japan by Toyota between 1968 and 2004. Prior to 1972, the model was marketed as the Toyota Corona Mark II. In some export markets, Toyota marketed the vehicle as the Toyota Cre ...

, the

Toyota Corona The is an automobile manufactured by the Japanese automaker Toyota across eleven generations between 1957 and 2001. On launch, the Corona was Toyota's next to highest product in their range, just below the Crown. The Corona was marketed i ...

, the

Toyota Carina The is an automobile which was manufactured by Toyota from December 1970 to December 2001. It was introduced as a sedan counterpart of the Celica, with which it originally shared a platform. Later, it was realigned to the Corona platform, but re ...

, the

Toyota Corolla The is a series of compact cars (formerly subcompact) manufactured and marketed globally by the Toyota Motor Corporation. Introduced in 1966, the Corolla was the best-selling car worldwide by 1974 and has been one of the best-selling cars in ...

, and the

Toyota Sprinter The is a compact car manufactured by Toyota as a variant of the Toyota Corolla. Exclusively sold in the Japanese domestic market, the Sprinter was aimed to be sportier than its Corolla sibling, with the Sprinter being sold at the ''Toyota Auto S ...

. There were three different versions initially introduced, called TTC-C for Catalyst, installing a

catalytic converter A catalytic converter is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. Catalytic converters are usually ...

, TTC-V for Vortex, installing an

exhaust gas recirculation In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide () emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. EGR works by recirculating a portion of an engine's exhaust ...

valve, and TTC-L which used a

lean burn Lean-burn refers to the burning of fuel with an excess of air in an internal combustion engine. In lean-burn engines the air:fuel ratio may be as lean as 65:1 (by mass). The air / fuel ratio needed to stoichiometrically combust gasoline, by con ...

method. As Toyota's technology evolved the three systems were eventually used in conjunction in future models. The TTC-V was a licensed copy of Honda's

CVCC CVCC, or , is an internal combustion engine technology developed and trademarked by the Honda Motor Company. The technology's name refers to its primary features: Compound refers to the use of two combustion chambers; Vortex refers to the vor ...

system, and was first introduced in February 1975. It was only available in the Carina and Corona lines, and only on the 19R engine, a modified 18R. From March 1976 the TTC-V system was upgraded to meet the stricter yet 1976 emissions standards. The TTC-V engine was discontinued in 1977. The "Vortex" approach was also used with Mitsubishi's MCA-Jet technology, with Mitsubishi installing an extra valve in the cylinder head, as opposed to Honda's pre-chamber approach. Toyota installed its emission control technology in select

Daihatsu , commonly known as Daihatsu, is a Japanese automobile manufacturer and one of the oldest surviving Japanese internal combustion engine manufacturers. The company's headquarters are located in Ikeda, Osaka Prefecture. Historically, Daihatsu was ...

vehicles, as Toyota was a part owner. The system was labeled "DECS" (Daihatsu Economical Cleanup System). The first version to be installed was the DECS-C (catalyst) in the

Daihatsu Charmant The Daihatsu Charmant is a subcompact sedan built by Daihatsu of Japan, based on the Toyota Corolla. It was succeeded by the Daihatsu Applause two years after Charmant production ended. The Charmant was heavily based on the E20 Toyota Corolla; ...

and the Consorte. As the Japanese emissions regulations continued to be tightened, the DECS-C system was replaced by the DECS-L (lean burn)ダイハツ希薄燃焼方式 DECS-L 広報資料 - ダイハツ工業 1976/05 method which was also installed in the

Daihatsu Fellow F, or f, is the sixth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''ef'' (pronounced ), and the plural is ''efs''. His ...

, on the

Daihatsu A-series engine The Daihatsu A-series engine is a range of compact two-cylinder internal combustion piston engines, designed by Daihatsu with the aid of their owner Toyota. Petrol-driven, it has cast iron engine blocks and aluminum cylinder heads, which are of a s ...

, the

Daihatsu Charade The Daihatsu Charade is a supermini car produced by the Japanese manufacturer Daihatsu from 1977 to 2000. It is considered by Daihatsu as a "large compact" or "supermini" car, to differentiate it from the smaller ''kei car'' compacts in its line- ...

, and the

Daihatsu Delta The Daihatsu Delta is an automotive nameplate that has been used on a variety of Japanese Daihatsu trucks and vans between 1970 and 2010. They have usually been Toyota-based, or otherwise based on models from the Toyota-owned Hino Motors. The t ...

References

Engine technology Engines Automotive technology tradenames {{Auto-stub