Scion tc question (only if u have automatic or know what ur talking about)?

-3-2-1 do not offer "more traction" They have absolutely nothing to do with traction. They are merely larger gears (despite their smaller numbering). It's more about torque to your drive wheels (the ones that spin when you floor it!) The 3-2-1 options are basically so your engine can run at lower revolutions, using larger gears, getting better mechanical advantage so your engine won't strain as it would if left in -D- (Drive). If you are towing a heavy load or carrying Rosie O'Donnell you'd want the lower numbered gears, but in Houston, -D- (Drive) will get you everywhere you need to go until you bury your baby on a sandy beach. haha For Example: Use -1- if you need to tow a Semi, and -3- for towing a small boat or jetski.