Measuring the Carbon Footprint of Environmental Tires Across Their Life Cycle (LCA)

2025-09-03

We have calculated the life cycle CO₂ emissions of the environmental tires developed by LIPPER K.K. This report highlights our efforts to reduce environmental impact throughout the entire life cycle, from manufacturing and use to disposal.

I. Introduction

This document discloses the results of converting the amount of greenhouse gas (GHG) emitted over the entire life cycle of a Environmental tire developed by LIPPER K.K. into CO2 in accordance with the “LCCO2 Calculation Guidelines for Tires” (see (1)) published by the Japan Automobile Tire Association, together with the calculation method. As in reference (1), some factors used in the calculation and GHG emissions are not disclosed.

II. Approach to LCCO2 Calculation

Baseline Flow and Functional Units

The reference flow in this guideline is the life cycle of one tire:

PCs (passenger cars) sold in Japan

・PC Environmental tire

・PC General tires

The functional unit of these tires is the basic mobility of the tire, such as load bearing, force transmission, and rotation with little resistance. Noh and sufficient running life to wear out completely.

In this guideline, 30,000 km of PC tire is exemplified as the running life.

The scope of the life cycle to be calculated (system boundary), the assessment of the impact of the life cycle, the accuracy of the calculation, and the consistency of the standard are also based on Reference (1).

III. Calculation method at each stage (inventory analysis)

The calculation methods at each stage and calculation examples based on the representative tire are shown below.

The representative tire size was selected using the domestic sales volume data for each tire size in JATMA as of 2019, and the weight was determined based on the JATMA survey.

Method of selecting representative tire size:

As in Reference (1), we selected 195/65R15, which is closer to the average weight and has the largest number of sales.

Table 1. representative tire size

Tire category	Representative tire size
PC	195/65R15

Table 2. Weight of the representative tire

(unit: kg)

Tire category		Weight
PC	Environmental tire	8.6
PC	General tire	8.6

1. Raw material procurement stage

1) Composition ratio of raw materials

Examples of typical raw material composition ratios for each tire are shown in the table below. The composition ratio of Environmental tires was determined based on MHI’s research, and PC General tires were determined based on JATMA’s research.

Table 3. Typical tire material composition ratio (weight ratio) *

Material name		General tire	Environmental Tires
New rubber		100	100
	Natural rubber	39	30
	Synthetic rubber	61	40
	LIPPER(NR100-18)	–	30
LIPPER_CNF		–	6
Carbon black		50	0
Process oil		8	15
Organic rubber chemical meter		8	24
Inorganic compounding agent		7	56
	Zinc oxide	3	5
	Titanium oxide	–	5
	Sulphur	3	2
	Silica	1	44
Fiber meter		10	8
Steel cord		15	14.1
Bead Wire		8	9.5
Total		206	232.6
Tire actual weight/New rubber weight ratio		2.06	2.32

*Set new rubber weight as 100

2) GHG emissions from raw material production

1. GHG emission factors for the production of each raw material

GHG in the production of each raw material Emission factors are shown in the table below.

Table 4. GHG emission factors for the production of tire materials

(Unit: kgCO2e/kg)

Material name		GHG emission factor	Source and basis
New rubber		–	–
	Natural rubber	6.71×10-1	P.W.Allen, The Malaysian Rubber Producers Research Association “Energy accounting. natural versus synthetic rubber” Rubber development vol32, no4, 1979
	Synthetic rubber	3.71	Emission factors for styrene-butadiene rubber and butadiene rubber from IDEA were calculated by weighted average of the percentage of synthetic rubber shipped for tires and tubes (Japan Rubber Industry Association statistics, 2018 results).
LIPPER_ Natural Rubber		1	Results of our measurements
LIPPER_CNF		2.003	Results of our measurements
Carbon black		***	JLCA Database, Carbon Black (2017)
Process oil		***	IDEA, lubricating oil (including grease) *Unit conversion using JATMA survey specific gravity of 0.88 kg/L
Organic rubber chemical meter		***	IDEA, Organic Rubber Chemicals
Inorganic compounding agent		–	–
	Zinc oxide	***	IDEA, Zinc Oxide
	Titanium oxide	***	IDEA, Titanium Oxide
	Sulphur	***	IDEA, recovered sulfur
	Silica	***	IDEA, silica gel
Fiber meter		7.16	Emission factors for IDEA polyester tire cord, nylon tire cord and rayon were calculated as weighted averages of consumption percentages (JATMA statistics, FY 2018 results).
Steel cord		***	IDEA, wire rope (including stranded wire)
Bead Wire		***	IDEA, wire rope (including stranded wire)

*IDEA: LCI Database IDEA version 2.3 (2019/12/27) IDEA Lab, National Institute of Advanced Industrial Science and Technology

2. Calculation of GHG emissions from the production of raw materials per tire

The GHG emissions from the production of raw materials per tire are given by:

(GHG emissions in the production of raw materials ((kgCO2e/piece)) =Σ {(tire weight (kg)) × (composition ratio of each raw material)× (GHG emission factor for the production of raw materials (kg-CO2e/kg))}

Table 5. GHG emissions from raw material production

(Unit: kgCO2e/piece)

Material name		General tire	Environmental tire
New rubber		–
	Natural rubber	1.1	0.7
	Synthetic rubber	9.4	5.2
LIPPER_ Natural Rubber		–	1.1
LIPPER_CNF		–	0.4
Carbon black		***	0
Process oil		***	0.4
Organic rubber chemical meter		***	6.2
Inorganic compounding agent		–
	Zinc oxide	***	0.5
	Titanium oxide	–	0.3
	Sulfur	***	0.001
	Silica	***	2.6
Fiber meter		***	2.0
Steel cord		***	1.6
Bead Wire		***	1.1
Total		***	21.9

3) GHG emissions from transportation of raw materials

1) Setting for transportation of raw materials

In the transportation of raw materials, the distances shown in the table below are specified.

Table 6. Setting Up Material Transportation Scenarios

Material name	Transpor distance	Remarks
Natural rubber	Land transport before shipping: 500 km International shipping: Goods shall arrive in Japan from the country of origin (Southeast Asian countries) via Singapore (1st hub), Shanghai, etc. (2nd hub). Land transport after shipping: 500 km	・Transport before and after international shipping shall be 500 km one-way by 10 ton truck with a loading rate of 50%. (As transportation between prefectures, the distance between Tokyo and Osaka is assumed.) ・International shipping feeder ships shall be 2,000TEU and this ship shall be 10,000TEU or more. (JATMA survey results, 2019)
Synthetic rubber	Land transport 500 km	・Tokyo – Osaka distance assumed ・Transport: 10 ton truck, load factor Set at 50%.
Carbon black
Process oil
Organic rubber chemical meter
Zinc oxide
Sulfur
Silica
Fiber meter
Dteel cord
Bead Wire

Table 7. GHG Emission Factors for Transportation of Raw Materials

(Unit: kgCO2e/kg)

Material name	GHG emission factor	Remarks
Natural rubber	2.97×10-1	JATMA Survey Results (2019) ・HMS surveyed GHG emissions from 18 major shipping routes ・Land transportation is calculated by fuel consumption ×GHG emission factor/loaded weight Fuel consumption calculation formula: based on the Act on the Rational Use of Energy (Energy Conservation Act) ln x=2.71-0.812 ln (y/100)-0.654 ln z x: fuel consumption per freight (l/ton-km) y: loading rate (%) z: maximum cargo capacity of truck (kg) GHG emission factor of diesel :***kgCO2e/l (IDEA, combustion energy of diesel oil)
Synthetic rubber	***	Calculated by the above ground transportation method
LIPPER Natural Rubber	***
LIPPER_CNF	***
Carbon black	***
Process oil	***
Organic rubber chemical meter	***
Zinc oxide	***
Titanium oxide	***
sulfur	***
Silica	***
Fiber meter	***
Steel cord	***
Bead Wire	***

2) Formula for calculating GHG emissions from the transport of raw materials per tire

The GHG emissions from the transport of raw materials per tire are given by:

(GHG emissions from transportation of raw materials (kgCO2e/unit))

=Σ {(tire weight (kg)) × (composition ratio of each raw material) ×(GHG emission factor for transport of raw materials (kgCO2e/kg))

Table 8. GHG emissions from transportation of raw materials

(Unit: kgCO2e/piece)

Material name		General Tire	Environmental tire
New rubber		–	–
	Natural rubber	0.48	0.31
	Synthetic rubber	***	0.13
LIPPER_ Natural Rubber		***	0.1
LIPPER_CNF		***	0.02
Carbon black		***	0
Process oil		***	0.05
Organic rubber chemical meter		***	0.08
Inorganic compounding agent		***	–
	Zinc oxide	***	0.02
	Titanium oxide	–	0.02
	Sulphur	***	0.01
	Silica	***	0.15
Fiber meter		***	0.03
Steel cord		***	0.05
Bead Wire		***	0.03
Total		1.15	1.00

4) GHG emissions at the entire raw material procurement stage

GHG at the entire raw material procurement stage Emissions are shown in the table below. (GHG emissions at the entire raw material procurement stage)

= (GHG emissions from the production of raw materials) + (GHG emissions from the transport of raw materials)

Table 9. GHG emissions at the entire raw material procurement stage

(Unit: kgCO2e/piece)

		PC
Category		General tire	Environmental tire
Raw material procurement stage	Raw material production	26.3	21.9
	Raw material transportation	1.1	1
	Total	27.4	22.9

2. Production and distribution stages

As our Environmental tire is currently under development, it is not possible to accurately calculate GHG emissions at the production and distribution stages, so we use the results of the PC fuel-efficient tire (see (1) for a detailed calculation method).

3. Stage of use

For the tire use stage, the contribution of tires to the GHG emissions emitted as the tires are fitted to the vehicle and the vehicle is driven is allocated and calculated.

1) Setting of tire operating conditions

The tire operating conditions for which GHG emissions are calculated are shown in Table 10.

For these representative tire sizes, RRC Values are examples only, not market averages.

Table 10. Establishment of tire use conditions to calculate GHG emissions

Category	PC		Unit	Remarks
Category	General Tire	Environmental tire	Unit	Remarks
Tire Size	195/65R15
Tire rolling resistance coefficient (RRC)	10.5	9.5		JATMA selection *
(Tire Rolling Resistance Index)	100	90	%	General Tire＝100
Vehicle fuel economy	15.25	16.3	km/l	JATMA survey result
Vehicle fuel economy	0.0656	0.062	l/km	JATMA survey result
Fuel consumption contribution of tires	0.179	0.17
Vehicle Fuel	Gasoline		–
Number of mounted tires	4		piece
Tire running life	30,000		JATMA survey result

*Based on the Report on the Investigation and Analysis of Tire Usage Period (the Ministry of the Environment, 2016, 2017.) and the Report on the Japan Greenhouse Gas Inventory (Center for Global Environmental Research, National Institute for Environmental Studies, 2020).

Using the fuel economy (0.0538 l/km) caused by factors other than the tire rolling resistance calculated in Reference (1), the vehicle fuel economy and the contribution of the tire fuel economy assuming that a PC Environmental tire with RRC=9.45 is installed are calculated as follows.

Fuel economy of a vehicle equipped with PC Environmental tires = Fuel economy attributable to tire rolling resistance + Fuel economy attributable to resistance other than tire rolling resistance

= 0.0027 ÷ 2.4 x 9.45 + 0.0538

= 0.0644 (l/km)

Fuel consumption contribution ratio of PC Environmental tires = fuel consumption attributable to tire rolling resistance ÷ vehicle fuel consumption

= 0.0027 / 2.4 x 9.45 / 0.0644

= 0.165

2) GHG emissions at the use stage

1. GHG emission factors for vehicle fuels

Table 11. GHG emission factors for vehicle fuels

(Unit: kgCO2e/l)

Category	GHG emission factor	Source
Gasoline	2.84	IDEA, gasoline combustion energy
Diesel oil	2.99	IDEA, combustion energy of diesel oil

2. Tire-induced fuel consumption (l/km) and GHG emissions

The fuel consumption (l/km) and GHG emissions attributable to tires are given by: (Tire-induced fuel consumption (l/km))

= (fuel consumption per kilometre per tire (l/km)) x (tire running life)

= (vehicle fuel consumption) × (contribution ratio of tire fuel consumption) ÷ (number of tires) × (tire running life)

(tire-induced GHG emissions) = (tire-induced fuel consumption (l/km)) x (vehicle fuel GHG emission factor)

Table 12. Fuel consumption (l/km) and GHG emissions from tires

Category	PC		Unit
Category	General Tire	Environmental tire	Unit
Tire-induced fuel consumption per kilometre per tire (l/km)	***	2.65×10-3	l/km/book
Tire-induced fuel consumption (l/km)(per tire life)	***	79.7	l/piece
GHG emissions from tires (per tire life)	250.5	226.4	kgCO2e/piece

4. Disposal and recycling stages

Calculate GHG emissions at the disposal and recycling stage.

1)GHG emissions from the transport of used tires

1. Setting conditions for the transport of used Tires

The GHG emissions of the transport of used Tires are calculated under the conditions set out in Table 13.

Table 13. Setting conditions for the transport of used Tires

Category	Content	Remarks
Subject	Transport of used tires from sites (dealers, etc.) to waste treatment facilities	–
Transport distance	100 km one-way transport	As transportation within the prefecture, the distance between prefectural borders is assumed.
Means of transportation	two-ton truck	JATMA settings
Loading ratio	50%	JATMA settings
Fuel economy formula	Compliant with the Act on the Rational Use of Energy (Energy Conservation Act)	ln x=2.71-0.812 ln (y/100)-0.654 ln z x: fuel consumption per freight (l/ton-km) y: loading rate (%) z: maximum laden capacity of the truck (kg)
GHG emission factor for diesel oil	***kgCO2e/l	IDEA, combustion energy of diesel oil
Used GHG of Tire transport emission factor	0.0547kgCO2e/kg	Fuel consumption x GHG emission factor/loaded weight

2. GHG emissions from used tire transport

The transport GHG emissions per used tire are given by: (GHG emissions from transport of used Tires)

= (weight of used tires) x (GHG emission factor for transport of used tires)

Table 14. Transport GHG emissions per used tire

Category	PC		Unit
	General tire	Environmental tire
New Tire weight (a)	8.6	8.2	kg	From Table 2
Abrasion rate (b)	15		%	*
Weight of used Tires (a) x (1-b)	7.3	7	kg
GHG emission factors for transport of used Tires (c)	0.0547		kgCO2e/kg	From Table 13
GHG emissions from used Tire transport	0.4	0.38	kgCO2e/piece
(a)x(1-b)×(c)

* Weight loss% for total wear is set based on calculation of tire specifications, etc.

2) GHG Emissions and Emission Reduction Effects of Heat Use

1. GHG emissions from heat use

a) Carbon content in new tires

The carbon content of the tire is determined from the tire raw material composition ratio and the carbon content ratio of each raw material. Renewable materials (natural rubber) were excluded from the carbon content because they were regarded as carbon-neutral materials.

In addition, for heat utilization of used tires, a process for cutting the tires may be required. It was excluded because the emissions were very small (about 1/1,000) compared to tire combustion.

Table 15. Carbon content in new tires *1

Material name		Carbon content (considering carbon neutrality)		Carbon content ratio	Carbon neutral *3
		PC		*2
		General tire	Environmental tire
New rubber		–	–	–	–
	Natural rubber	0	0	0.88	0
	Synthetic rubber	54.3	35.6	0.89	1
LIPPER_ Natural Rubber		0	0
LIPPER_CNF		0	0
Carbon black		49	0	0.98	1
Process oil		6.7	12.6	0.84	1
Organic rubber chemical meter *4		5.4	16.8	0.67	1
Inorganic compounding agent		–	–	–	N
	Zinc oxide	0	0	0	N
	Titanium oxide	–	0	0	N
	Sulphur	0	0	0	N
	Silica	0	0	0	N
Fiber meter		6.2	5	0.62	1
Steel cord		0	0	0	N
Bead Wire		0	0	0	N
Total		121.6	69.2	–	–
Carbon content in tires * 5		0.59	0.3	–	–

*1: Weight index when the weight of new rubber is 100. Calculated by multiplying the raw material composition ratio in Table 3 by the carbon content ratio

*2: The carbon content ratio of each raw material is estimated by JATMA based on the basic molecular structure.

*3: carbon neutral =0, not carbon neutral =1, raw material without carbon content =N

*4: Organic rubber drugs were calculated from the basic molecular structures of typical vulcanization accelerators and anti-aging agents.

*5: Calculated by dividing the carbon content meter in this table by the total weight index (206.0 in the case of PC general tires) when the weight of new rubber in Table 3 is 100.

b) Changes in material constituents and carbon content after tire wear

Since tire wear consists only of rubber components, the weight of the total component weight minus the weight of the fiber gauge, steel cord and bead wire was subtracted proportionally.

Table 16. Change in carbon content due to wear loss

Category		PC		Remarks
Category		General tire	Environmental tire	Remarks
New tire	Composed weight (a)	206	232.6	*1
	Weight of wear components (b)	173	231	*2
	Carbon content (c)	121.6	69.24	Calculated in Table 15
	Carbon content (d)	59.00%	29.80%	Calculated in Table 15
Used tire	Composed weight (e)	175.1	197.7	(a)x (1- Abrasion rate) *3
	Weight of wear components (f)	142.1	196.1	(b)-(a-e)
	Carbon content (g)	101	59.5	*4
	carbon content	57.70%	30.10%	(g)/(e)

*1. Table 3: Weight index with new rubber content of 100

*2 Component weight (a) minus fiber meter, steel cord and bead wire (rubber compound weight index)

*3 As described in Table 14

*4. Carbon content meter of new wear components (Total for natural rubber, synthetic rubber, carbon black, process oil, and organic rubber drugs in Table 15) x ((f) ÷ (b)) + carbon content of new steel cord, bead wire and fiber meter

c) GHG emissions per kilogram of used tires burned

The GHG emissions per kilogram of Tire during the combustion of used Tires are given by the following equation: (GHG emissions per kg of Tire from used Tire combustion)

= (carbon content of used Tires) × 44 ÷12

Table 17. GHG emissions per kilogram of used tires burned

d) GHG emissions per tire when used tires are burned

The GHG emissions per tire during the combustion of used tires are determined by the following equation: (GHG emissions per Tire from used Tire combustion)

= (GHG emissions per kilogram of Tire from used Tire combustion)

x (used Tire weight)

Table 18. GHG emissions per tire when used tires are burned

Category	General Tire	Environmental tire	Remarks
GHG emissions per kilogram of used tires burned	2.114	1.104	kgCO2e/kg
Weight of used tires	7.3	7.0	kg
GHG emissions per tire when used tires are burned	15.5	7.7	kgCO2e/piece

2. GHG Emission Reduction Effects of Heat Use

By using used tires as a heat source to recover energy, it can be assumed that fossil fuel consumption is replaced and GHG emissions are reduced, and the reduction effect is calculated.

a) Fossil fuel substitutes for heat from used tires

The paper industry is cited as the main heat application of used tires. As a result of the hearing with the paper manufacturers, used tires are mainly used instead of C heavy oil. Therefore, it is assumed that the used tires have replaced C heavy oil.

b) GHG emission reduction effect of heat utilization of used tires

GHG from heat utilization of used tires The emission reduction effect is calculated by the following equation.

(Effect of reducing GHG emissions from heat use of used tires)=

(GHG emission factor of C heavy oil) x (calorific value of tire) x (weight of used tire)

Table 19. GHG emission reduction effect of heat utilization of used tires

Category	PC		Unit	Remarks
Category	General tire	Environmental tire	Unit	Remarks
GHG emission factor for C heavy oil	***		kgCO2e/MJ	*1
calorific value of the tire	***		MJ/kg	*2
Weight of used tires	7.3	7	kg	From Table 14
GHG reduction effect	-20.4	-19.4	kgCO2e/piece

*1 Combustion energy of IDEA C heavy oil

*2. Higher calorific value of IDEA waste tires

c) GHG emissions from heat use (total)

GHG in heat use Emissions (total) are calculated by the following formula:

For the aggregated results, see “Table 20. GHG Emissions and Emission Reduction Effects at the Disposal and Recycling Stage.” (GHG emissions from heat use)

= (GHG emissions from the transport of used Tires)

+ (GHG emissions per Tire from used Tire combustion)

– (GHG emission reduction benefits from heat use of used tires)

3) GHG Emissions and Emission Reduction Effects at the Disposal and Recycling Stage

GHG Emissions and Emission Reduction Effects at the Disposal and Recycling Stage

The GHG emissions for each recycling method were weighted by the recycling ratio (78% heat use), and the GHG emissions at the disposal stage and the emission reduction effect of recycling were shown in the table below.

Table 20. GHG Emissions and Emission Reduction Effects at the Disposal and Recycling Stage

(Unit: kgCO2e/piece)

Category		PC		Remarks
		General tire	Environmental tire
Recycling ratio	Heat utilization	78%		Figure 4
	Other than recycling	22%
GHG Emissions	Transportation	0.4	0.4	TABLE 26
	Heat utilization	12.1	6	GHG emissions in Table 30
				× Ratio of heat use
	Simple incineration	3.4	1.7	GHG emissions in Table 30
				× Ratio other than recycling
Emission reduction effect	Heat utilization	-15.9	-15.2	GHG emission reductions x heat share in Table 31

5. Life-Cycle GHG emissions

Life-Cycle GHG based on representative Tires Total emissions are shown below.

Table 21. Lifecycle GHG Emissions (Details)

(Unit: kgCO2e/piece)

Category			General Tire	Environmental tire
Procurement of raw materials stage		Raw material production	26.3	21.9
Procurement of raw materials stage		Raw material transportation	1.1	1.00
Production stage		Production	6.9	6.6
Distribution stage		Transportation	0.9	0.9
Stage of use		Use	250.5	226.4
Disposal and recycling stage	Emissions	Transportation	0.4	0.4
		Heat utilization	12.1	6.0
		Simple incineration	3.4	1.69
Total GHG emissions			301.5	264.9
Disposal and recycling stage	Reduction effect	Heat utilization	-15.9	-15.2
Life-cycle GHG emissions (including reduction effects)			285.6	249.7

Table 22 Life-Cycle GHG Emissions by Stage

(Unit: kgCO2e/piece)

Category		General tire		Environmental tire
Raw material procurement stage		27.4	9.60%	22.9	8.99%
Production stage		6.9	2.40%	6.6	2.59%
Distribution stage		0.9	0.30%	0.9	0.33%
Stage of use		250.5	87.70%	226.45	88.90%
Disposal and recycling stages		0	0.00%	-2.2	-0.86%
	Discharge	15.9	5.60%	13	5.11%
	Emission reduction effect	-15.9	-5.60%	-15.2	-5.95%
Total		285.6	100.00%	254.6	100.00%

Life Cycle GHG Emissions per Tire (kg CO₂e)

Life Cycle GHG Emissions per Tire (table)

Passenger Car General Tire — Life Cycle GHG Emissions per Tire = 285.6 kg CO₂e
Passenger Car Environmental Tire — Life Cycle GHG Emissions per Tire = 212.0 kg CO₂e

	Raw material procurement stage	Production	Distribution	Stage of Use	Disposal and recycling stages
Passenger Car General Tire	27.4kgCO₂e 9.6％	6.9kgCO₂e 2.4%	0.9kgCO₂e 0.3%	250.5kgCO₂e 87.7%	0.0kgCO₂e 0.0%
Passenger Car General Tire	Note: GHG emissions at the disposal/recycling stage — Emissions = 15.9 kg CO₂e, Reduction effect = –15.9 kg CO₂e
Passenger Car Environmental tire	22.9kgCO₂e 8.99％	6.6kgCO₂e 2.59%	0.9kgCO₂e 0.33%	188.7kgCO₂e 89.0%	-2.2kgCO₂e -0.86%
Passenger Car Environmental tire	Note: GHG emissions at the disposal/recycling stage — Emissions = 13.0 kg CO₂e, Reduction effect = –15.1 kg CO₂e

In this article, the life of each tire is considered to be the same, and the evaluation per tire is conducted.

A comparison on a per Tire basis is not appropriate when comparing Tires. In this case, for example, comparison per unit distance can be considered. In this case, as shown in this document, LCCO2 can be calculated for each tire with a different running life, and then converted into emissions per unit running distance for relative comparison.

GHG emissions per unit mileage = tire LCCO2 x unit mileage / mileage