2018 Kia Optima Lug Nut Torque & Bolt Specs

The 2018 Kia Optima lug nut torque is 80 ft-lbs (108 Nm) on M12x1.5 studs. Torque in a star pattern in two passes (snug, then final), and re-check after the first 50–100 miles of driving. Use a calibrated torque wrench — not an impact gun — for the final pass.

Lug nut torque: 80 ft-lbs (108 Nm) · Thread: M12x1.5.

This page is the OEM-referenced fastener summary for the 2018 Kia Optima. Use it before any maintenance or repair job where torque values matter — brake work, wheel changes, suspension service, engine teardowns, or oil changes. Specs are pulled from manufacturer service literature, cross-checked against community data, and updated as new chassis variants become available.

Hyundai/Kia lug-nut torque is 79-88 ft-lbs on nearly all passenger models, M12x1.5 thread, 21mm socket. The Tucson, Sportage, and Santa Fe all use the same fastener spec. Hyundai's oil drain plug threads are unusually fine-pitch and strip easily — always use a torque wrench, not feel.

Common fastener categories on the 2018 Kia Optima

Wheel / lug nut torque and thread spec (covered above)
Brake caliper bracket bolts (typically 80-130 ft-lbs) and slide/guide pins (18-35 ft-lbs)
Engine oil drain plug torque — rarely above 30 ft-lbs; always use a new crush washer
Transmission pan, valve cover, and intake manifold bolts (low torque, often 89-106 in-lbs)
Suspension control arm, sway bar, tie rod end and ball joint torque
Spark plug torque (typically 10-15 ft-lbs on aluminum heads — do not exceed)
Differential cover bolts (RWD/4WD only) and transfer case fasteners

Repair guidance for this model year

For 2018 model-year work: This era introduced widespread torque-to-yield (TTY) bolts on head, main, and crank pulley fasteners. TTY bolts stretch permanently when torqued and must not be reused — the spec calls for a fresh bolt every time. Always verify TTY status against the FSM before reassembly.

Tools you will need

Metric socket set (8mm-22mm), 6-point impact-rated
Calibrated torque wrench (10-150 ft-lbs covers most automotive jobs; add a 0-250 ft-lbs wrench for truck lug nuts)
Breaker bar (24" minimum) for initial loosening
Penetrating oil (PB Blaster or Kroil) for any fastener over 5 years old
Anti-seize on stainless or dissimilar-metal threads; thread-locker (Loctite blue) on critical reassembly

Frequently asked questions

What is the lug nut torque on a 2018 Kia Optima?

The OEM-specified lug-nut torque for the 2018 Kia Optima is 80 ft-lbs (108 Nm) on M12x1.5 thread studs. Use a calibrated torque wrench in a star pattern, in two passes (50% and 100%), and re-check after 50-100 miles of driving.

What socket size do I need for the 2018 Kia Optima lug nuts?

Most modern Kia vehicles use a 19mm or 21mm socket. Older Kia models from before 2000 may use a 13/16" SAE socket on certain trims. Confirm against the actual lug before purchasing aftermarket wheels.

Are the 2018 Kia Optima fasteners metric or SAE?

Metric is the standard for this vehicle. Most fasteners on this vehicle are metric (M6, M8, M10, M12, M14). Bring a full metric set; SAE substitutes can round the head. Bolt-head markings are the fastest way to confirm grade and material at the bench.

Other Kia Optima years

Same model, different model year — fastener spec may change. Always confirm against the year for your VIN.

→ 2018 Kia Optima oil drain plug torque & size

→ 2018 Kia Optima suspension & steering torque specs (control arm, ball joint, tie rod)

→ 2018 Kia Optima axle nut torque spec (CV axle & hub nut)

All 25 2018 Kia Optima fastener specs

Per-bolt torque, wrench size, and thread spec for the 2018 Kia Optima, sourced from OEM service literature and verified against community shop data. Values pair imperial (ft-lb) and metric (Nm) where the manufacturer publishes both. 2 of the 25 fastener specs on this page are independently verified against OEM service manuals and manufacturer torque data.

Wheels — 2018 Kia Optima

Wheel and lug nut spec for the 2018 Kia Optima. Lug nut tightens to 80 ft-lbs (108 Nm), takes a 21mm driver, runs on M12x1.5 threads, located at the all four wheels.

Engine — 2018 Kia Optima

Engine bolt-by-bolt torque for the 2018 Kia Optima, including the long block, valve covers, and intake. The valve cover bolt is a M6x1.0 thread, torqued to 7-10 ft-lbs. The alternator mounting bolt torques to 30-40 ft-lbs (M10x1.25 thread). plan for the right driver on a M14x1.5 stud; final torque is 25 ft-lbs (34 Nm) (oil drain plug). Spark plug tightens to 13-17 ft-lbs, runs on M14x1.25 threads.

Drivetrain — 2018 Kia Optima

Drivetrain and driveline fasteners for the 2018 Kia Optima — axle, transmission, and differential plugs. The transmission mount bolt torques to 55-70 ft-lbs (M12x1.25 thread). plan for the right driver on a M24x1.5 stud; final torque is 170-200 ft-lbs (axle nut front). Axle nut rear tightens to 170-200 ft-lbs, runs on M24x1.5 threads.

Suspension — 2018 Kia Optima

Suspension and chassis fastener torque for the 2018 Kia Optima — strut, control arm, and sway bar values. plan for the right driver on a M10x1.25 stud; final torque is 25-35 ft-lbs (stabilizer bar link nut front). Front lower control arm front bolt tightens to 70-85 ft-lbs, runs on M12x1.25 threads. The rear shock absorber upper nut is a M12x1.25 thread, torqued to 35-45 ft-lbs. The front lower control arm rear bolt torques to 70-85 ft-lbs (M12x1.25 thread). plan for the right driver on a M14x1.5 stud; final torque is 30-40 ft-lbs (front strut top mount nut). Rear shock absorber lower bolt tightens to 85-100 ft-lbs, runs on M14x1.5 threads.

Steering — 2018 Kia Optima

Steering linkage fasteners on the 2018 Kia Optima. Steering wheel center bolt tightens to 30-38 ft-lbs, runs on M16x1.5 threads. The tie rod end nut is a M12x1.25 thread, torqued to 25-33 ft-lbs. The power steering pump bolt torques to 22-30 ft-lbs (M10x1.25 thread).

Body — 2018 Kia Optima

Body fasteners on the 2018 Kia Optima. The hood hinge bolt is a M8x1.25 thread, torqued to 15-20 ft-lbs.

Wheel — 2018 Kia Optima

Wheel fasteners on the 2018 Kia Optima. The wheel lug nuts torques to 80 ft-lbs (108 Nm) (M12x1.5 thread).

Brake — 2018 Kia Optima

Brake fasteners on the 2018 Kia Optima. plan for the right driver on a M10x1.25 stud; final torque is 22-30 ft-lbs (front brake caliper guide pin bolt). OEM-verified spec. Rear brake caliper guide pin bolt tightens to 20-28 ft-lbs, runs on M10x1.25 threads. Confirmed against manufacturer service literature. The rear brake caliper bracket bolt is a M12x1.25 thread, torqued to 50-65 ft-lbs. The front brake caliper bracket bolt torques to 55-70 ft-lbs (M12x1.25 thread).

Lug Nut — 2018 Kia Optima

Lug Nut fasteners on the 2018 Kia Optima. Wheel lug nut tightens to 80 ft-lbs (108 Nm), takes a 21mm driver, runs on M12x1.5 threads, located at the wheel.

Oil Drain Plug — 2018 Kia Optima

Oil Drain Plug fasteners on the 2018 Kia Optima. The engine oil drain plug uses a 17mm drive on a M14x1.5 thread, torqued to 25 ft-lbs (34 Nm) at the oil pan.

New to torquing wheels? Read our How lug nut torque works — the complete guide for star-pattern sequence, re-torque intervals, and how to read a lug spec — then use the 2018 Kia Optima numbers above.

Loading the interactive 2018 Kia Optima fastener lookup with per-bolt filtering, part links, and torque tools…