2018 Subaru WRX STi 100,000 KM Service in Vancouver

Owning a 2018 Subaru WRX STi means you value performance, precision, and reliability. But once your STi hits the 100,000 km milestone, proper maintenance becomes critical — not optional.

At Speed Projects Laboratory (SPL), we recently completed a comprehensive 100,000 km scheduled maintenance service on a 2018 STi, ensuring it continues to deliver peak turbocharged performance while protecting long-term engine and drivetrain health.

If you’re searching for:

Subaru WRX STi 100,000 km service cost
WRX STi major service Vancouver
EJ257 spark plug replacement
STi transmission and differential fluid service

This guide explains exactly what was done — and why it matters.

Vehicle: 2018 Subaru WRX STi (EJ257 Turbocharged Engine)

The 2018 WRX STi is powered by the legendary 2.5L EJ257 turbocharged boxer engine, paired with a 6-speed manual transmission and Subaru’s symmetrical AWD system. At 100,000 km, several major service items become essential to maintain:

Engine reliability
Turbo system health
Transmission and differential longevity
Brake performance
Suspension and steering integrity

Skipping or delaying this service can lead to expensive repairs — especially on high-performance turbocharged vehicles.

What’s Included in the 100,000 KM STi Major Service

Below is a breakdown of the full service we performed, following manufacturer recommendations and performance-shop best practices.

1. Engine Oil & Filter Replacement

Turbocharged engines like the EJ257 generate significant heat and pressure.

We:

Replaced engine oil with high-quality synthetic oil
Installed a new OEM-spec oil filter
Inspected for leaks or contamination

Why it matters:
Clean oil protects turbo bearings, piston rings, and camshafts — critical on performance Subarus.

2. Tire Rotation & Full Tire Inspection

We:

Rotated tires to ensure even wear
Inspected tread depth and wear patterns
Adjusted tire pressures including the spare

Why it matters:
Subaru AWD systems are sensitive to uneven tire wear. Incorrect tire circumference can stress the center differential.

3. Front & Rear Brake Service

The STi’s Brembo braking system requires regular inspection.

We:

Removed and inspected pads and rotors
Serviced caliper hardware
Cleaned and lubricated contact points
Checked for uneven wear or heat stress

Why it matters:
Performance braking systems require preventative servicing to avoid premature rotor or caliper issues.

4. Spark Plug Replacement (Major 100,000 KM Item)

Spark plugs were replaced as part of the scheduled service.

On the EJ257 engine, spark plug replacement is more labor-intensive due to the boxer layout.

Why it matters:

Restores combustion efficiency
Prevents misfires under boost
Maintains fuel economy and power delivery

Failing plugs in a turbocharged engine can cause detonation or long-term engine damage.

Transmission & Differential Fluid Replacement

For this service, we replaced:

6-speed manual transmission fluid
Front differential fluid
Rear differential fluid

We inspected drain plugs for metal debris and verified proper refill levels.

Why it matters:
The STi drivetrain is performance-oriented. Fresh gear oil protects:

Synchronizers
Bearings
Ring & pinion gears
Center differential components

Neglected fluids can result in grinding, whining, or costly rebuilds.

6. Cooling System Inspection

We:

Tested coolant condition
Inspected hoses and clamps
Checked for leaks or swelling

Turbo Subarus run hot. Cooling system integrity is critical to prevent overheating or head gasket issues.

7. Drive Belt Inspection & Adjustment

We inspected belt tension and wear, adjusting where necessary.

Worn or loose belts can:

Cause squealing
Reduce alternator efficiency
Affect accessory performance

8. Battery Service

Load-tested battery
Cleaned terminals
Checked charging output

Electrical health is often overlooked but critical for consistent performance.

9. Steering, Suspension & Underbody Inspection

We performed a full mechanical inspection:

Ball joints
Tie rods
Control arms
Bushings
Axle boots
Underbody damage

High-performance AWD vehicles benefit from routine suspension checks — especially in BC’s varying road conditions.

10. Filters Inspection

Engine air filter inspected
Cabin air filter inspected
Replaced if necessary

Proper airflow ensures:

Stable air-fuel ratios
Turbo efficiency
Clean cabin environment

11. Functional Checks & Road Test

We verified:

All exterior and interior lights
Wipers and washer operation
Fluid levels (brake, clutch, power steering, washer)
Road test to confirm drivability, clutch feel, brake performance, and transmission operation

The road test ensures everything performs exactly as it should under real-world driving conditions.

Why 100,000 KM Service Is Critical for WRX STi Owners

At this mileage, components begin to show natural wear. A proactive service approach:

Prevents turbocharger damage
Protects the AWD drivetrain
Extends engine life
Maintains resale value
Ensures safe braking and steering

Performance vehicles demand performance-level maintenance.

Frequently Asked Questions

How much does a 100,000 km service cost on a Subaru WRX STi?
Costs vary depending on spark plug replacement, transmission/differential fluid service, and brake condition. It is considered a major service interval.

Does the WRX STi need differential fluid changes at 100,000 km?
Yes. Subaru AWD systems require periodic differential fluid replacement to maintain drivetrain health.

When should spark plugs be replaced on a 2018 WRX STi?
Around 100,000 km under normal driving conditions, sooner if tuned or driven aggressively.

Is 100,000 km high mileage for a WRX STi?
Not if properly maintained. With regular servicing, EJ257 engines can remain reliable well beyond this mileage.