Variable

Best estimates in this study

I/M in Southern California’s South Coast Air Basin

Lower value

Upper value

PartiRate

90%

100%

100%

IndenRate

50%

71%

90%

GoodRep

72%

80%

80%

ExEm

81%

81%

92%

DurRep

86.5%

(79%)*

94%

IllegalVeh

10% for buses and heavy trucks, 20% for light trucks and motorcycles

13%

6.6%

Percent of overall PM₁₀ emission reduction by I/M

10.6%

19.1%

30.9%