1993 GMC Suburban Owner's Manual - Page 207

Hydroplaning doesn't happen often. But it can if your tires haven't much' tread or if thepressure in oneormore is low. It canhappen if a lot ofwater is standingontheroad. If youcanseereflectionsfromtrees,telephonepoles, orothervehicles,andraindrops"dimple"thewater'ssurface,therecouldbe hydroplaning. Hydroplaningusuallyhappensonhigherspeedroads.Therejustisn'tahard andfastruleabouthydroplaning.Thebestadviceis to slow downwhen it is raining,andbecareful. Some Other Rainy .Weather Tips e Turn on yourheadlights-not just, yourparkinglights-tohelpmake more visible to others. 8 you 8 e e Lookforhard-to-seevehiclescomingfrombehind. You maywanttouse f yourheadlightseven in daytime i it'sraininghard. Besidesslowingdown,allowsomeextrafollowingdistance.Andbe especially careful when you pass another vehicle. Allow yourselfmore clearroomahead;and be prepared to have your view restricted by road spray. I the road spray is so heavyyouareactuallyblinded,dropback. f .Don't,pass until conditions improve. Going more slowly is better than having accident. an Use yourdefoggerif it helps. Havegoodtireswithpropertreaddepth.(See"Tires" in theIndex.) ' ' . 4-39