1999 Toyota Sienna Owners Manual - Page 193
1999 Toyota Sienna Manual
Page 193 highlights
name. SIENNA (45403U) CAUTION D Do not mix summer and all season tires on your vehicle as this can cause dangerous handling characteristics, resulting in loss of control. D Do not use tires other than the manufacturer's designated tires, and never mix tires or wheels of the sizes different from the originally equipped tires and wheels. 193