Kia Optima 2017, Owner'S Manual, Page: 621 / 776

NO. ITEM REMARK
*5
Engine oil and engine oil filter
(For Diesel Engine)
• If the recommended oil is not available, replace engine oil
and engine oil filter every 20,000 km (13,000 miles) or 12
months.
• The engine oil level should be checked regularly and
maintained properly. Operating with an insufficient
amount oil can damage the engine, and such damage is
not covered by warranty.
• This maintenance schedule depends on fuel quality. It is
applicable only when using a qualified fuel <"EN590 or
equivalent">. If the diesel fuel specifications don't meet
the EN590, it must be replaced according to the severe
maintenance schedule.
*6 Fuel additives (Gasoline)
Kia recommends that you use unleaded gasoline which has
an octane rating of RON (Research Octane Number) 95 /
AKI (Antiknock Index) 91 or higher (for Europe) or Octane
Rating of RON (Research Octane Number) 91 / AKI (Anti‐
knock Index) 87 or higher (except Europe).
For customers who do not use good quality gasolines in‐
cluding fuel additives regularly, and have problems starting
or the engine does not run smoothly, one bottle of addi‐
tives added to the fuel tank at every 15,000 km
(10,000 miles) (for Europe)/10,000 km (6,500 miles) (ex‐
cept Europe). Additives are available from your authorized
Kia dealer along with information on how to use them. Do
not mix other additives.
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8
Maintenance