2011 Subaru Outback Owner's Manual - Page 385

11-34 Maintenance and service or icy roads, we strongly recommend the use of winter (snow) tires. When installing winter tires, be sure to replace all four tires. ! Winter (snow) tires Winter tires are best suited for driving on snow-covered and icy roads. However winter tires do not perform as well as summer tires and all season tires on roads other than snow-covered and icy roads. & Tire pressure monitoring system (TPMS) (if equipped) The tire pressure monitoring system provides the driver with a warning message by sending a signal from a sensor that is installed in each wheel when tire pressure is severely low. The tire pressure monitoring system will activate only when the vehicle is driven. Also, this system may not react immediately to a sudden drop in tire pressure (for example, a blow-out caused by running over a sharp object). If you adjust the tire pressures in a warm garage and will then drive the vehicle in cold outside air, the resulting drop in tire pressures may cause the low tire pressure warning light to illuminate. To avoid this problem when adjusting the tire pressures in a warm garage, inflate the tires to pressures higher than those shown on the tire placard. Specifically, inflate them by an extra 1 psi (6.9 kPa, 0.07 kgf/cm2) for every difference of 108F (5.68C) between the temperature in the garage and the temperature outside. By way of example, the following table shows the required tire pressures that correspond to various outside temperatures when the temperature in the garage is 608F (15.68C). Example: Tire size: P215/70R16 99S, P225/60R17 98T Standard tire pressures: Front: 32 psi (220 kPa, 2.2 kgf/cm2) Rear: 30 psi (210 kPa, 2.1 kgf/cm2) Garage temperature: 608F (15.68C) Outside temperature 308F (−18C) 108F (−128C) −108F (−238C) Adjusted pressure [psi (kPa, kgf/cm2)] Front 35 (240, 2.4) 37 (255, 2.55) Rear 33 (230, 2.3) 35 (240, 2.4) Rear: 32 psi (220 kPa, 2.2 kgf/cm2) Garage temperature: 608F (15.68C) Outside temperature 308F (−18C) 108F (−128C) −108F (−238C) Adjusted pressure [psi (kPa, kgf/cm2)] Front 36 (250, 2.5) 38 (265, 2.65) 40 (280, 2.8) Rear 35 (240, 2.4) 37 (255, 2.55) 39 (270, 2.7) 39 (270, 2.7) 37 (255, 2.55) If the low tire pressure warning light illuminates when you drive the vehicle in cold outside air after adjusting the tire pressures in a warm garage, re-adjust the tire pressures using the method described above. Then, increase the vehicle speed to at least 20 mph (32 km/h) and check to see that the low tire pressure warning light goes off a few minutes later. If the low tire pressure warning light does not go off, the tire pressure monitoring system may not be functioning normally. In this event, go to a SUBARU dealer to have the system inspected as soon as possible. While the vehicle is driven, friction between tires and the road surface causes the tires to warm up. After illumination of the low tire pressure warning light, any increase in the tire pressures caused by an increase in the outside air temperature Example: Tire size: P205/60R16 91V, P215/50R17 90V, P225/50R17 93V, 225/45R18 91W Standard tire pressures: Front: 33 psi (230 kPa, 2.3 kgf/cm2)