When Less is More – A Comparative Life Cycle Assessment of Aluminum and Steel Truck Wheels Casey Wagner Jonathan Provo Christoph Koffler, PhD
Alcoa & Sustainability
Alcoa Sustainability Advancing Each Generation for over 125 years!
Reduced GHG intensity in primary metal by 23% since 2005 Aggressive 2020 and 2030 goals for water, GHG, landfill waste, and mine rehabilitation More information available at www.alcoa.com/sustainability and www.alcoa.com/lca 3
Alcoa Wheel and Transportation Products
Commercial Vehicle Wheels (CVW)
Forged Specialty Wheels (FSW)
Transportation Products (ATP)
Market Segments
Medium & Heavy Duty Truck & Trailer
RV/Motor Home & Coach
Light Truck & Trailer
Automobile
More vehicles are fitted with Alcoa forged aluminum wheels than any other brand.
Global Presence with 14 Facilities in 9 Countries
* Alcoa facility connected to Alcoa Wheel and Transportation Products
Alcoa Background for the Study
• 2010 – WRI Road Test • Evaluated switching from an older model of aluminum wheel to newer lighter version (LvL One) • Sparked the interest of doing a more in depth evaluation of steel and aluminum wheels and also investigating other life cycle impacts • 2011 – began our relationship with PE
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Scope & Findings
Functional Unit and Reference Flows Aluminum
Steel
Function
Couple truck tires to vehicle hubs
Magnitude
Duration
A1: 18 wheels A1: 18 wheels A2: 10 wheels A2: 18 wheels B: 12 wheels B: 12 wheels 1,000,000 miles (US) / 1.500.000 km (EU)
Level of quality
22.5'' heavy-duty truck wheels
Reference flows:
A1: A2: B:
810 lbs. 554 lbs. 268 kg
US: US: EU:
1,224 lbs. 1,224 lbs. 483 kg
Carbon Return-on-Investment 𝑛𝑒𝑡 𝑠𝑎𝑣𝑖𝑛𝑔𝑠 − 𝑛𝑒𝑡 𝑚𝑎𝑛𝑢𝑓𝑎𝑐𝑡𝑢𝑟𝑖𝑛𝑔 𝑏𝑢𝑟𝑑𝑒𝑛 𝑐𝑅𝑂𝐼 = 𝑛𝑒𝑡 𝑚𝑎𝑛𝑢𝑓𝑎𝑐𝑡𝑢𝑟𝑖𝑛𝑔 𝑏𝑢𝑟𝑑𝑒𝑛
Mass-Restricted Case Truck with Alcoa Wheels
Truck with Steel Wheels
Payload (lbs)
45,414
45,000
Utilization rate
100%
100%
Gross Weight (lbs)
80,000
80,000
1,000,000
1,000,000
5.7
5.7
173,290
173,290
Use Phase CO2e (kg)
1,990,332
1,990,332
Total t*km
33,151,592
32,849,446
0.0600
0.0606
Distance (mi) Fuel Economy (mpg)
Diesel Consumed (gal)
kg CO2e / t*km
Mass-Restricted Case – Break Even
Total savings of 17.8 tons of carbon dioxide with a cROI of 466%
Volume-Restricted Case Truck with Alcoa Wheels
Truck with Steel Wheels
Payload (lbs)
13,500
13,500
Utilization rate
29.74%
30.00%
Gross Weight (lbs)
48,086
48,500
1,000,000
1,000,000
6.81
6.8
145,165
145,689
Use Phase CO2e (kg)
1,668,924
1,673,558
Total t*km
9,854,818
9,854,818
0.1694
0.1698
Distance (mi) Fuel Economy (mpg) Diesel Consumed (gal)
kg CO2e / t*km
Volume-Restricted Case – Break Even
Total savings of 4.1 tons of carbon dioxide with a cROI of 105%
Average Use Case – Break Even
• Based on a 31/69 volume-to-mass-restricted share (78% average utilization rate) • Total savings of 16.3 tons of carbon dioxide with a cROI of 426%
Average Use Case Sensitivity Analysis
End-of-Life Treatment Average Case Savings (t CO2)
MassRestricted Savings (t CO2)
Volume Restricted Savings (t CO2)
Value-Corrected Substitution
16.3
17.8
4.1
Avoided Burden
16.9
18.4
4.7
Cut-off
9.2
10.7
-2.9
EoL Scenario
Thank You!
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