See also:

Rear differential (4WD)
Checking or changing rear differential fluid Have rear differential fluid checked or changed by an Authorized Kia Dealer according to the Maintenance Schedule at the beginning of this section. ...

Dimensions
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IS BIGGER BETTER?
While we’d certainly argue that when it comes to cars bigger isn’t always better, the wider and longer Optima is now in line with its main competitors delivering added interior space. Rear sea ...