2003 Lexus GS 300/GS 430 Engine Oil Type, Capacity & Service Interval
Oil Type: 10W-40 · Capacity: 6.0 Quarts · Change Every 7,500 Miles
Engine
4.3L 8-Cylinder
Recommended Oil Type
10W-40
Viscosity grade
Oil Capacity
6.0 quarts
Including filter
Change Interval
7,500 miles
Or 9 months
Oil Filter
Fram PH6607A
Compatible part number
Engine Size
4.3L
8 Cylinders
Fuel Type
Gasoline
Manufacturer specified
The 2003 Lexus GS 300/GS 430 record on this page shows 10W-40 full synthetic engine oil with a 6.0-quart fill including the filter. Add the final amount slowly, then re-check the oil level after running the engine briefly. If your GS 300/GS 430 has a different engine, trim, or regional build, verify the final spec with the owner’s manual before service.
2003 Lexus GS 300/GS 430 Recommended Oil Type & Formulation
For the 2003 Lexus GS 300/GS 430, the manufacturer recommends 10W-40 full synthetic engine oil. Using the correct viscosity grade maintains proper lubrication across all operating temperatures and ensures your engine meets fuel economy specifications.
Use synthetic oil with a viscosity of 10W-40. Conventional oil is not recommended.
What does 10W-40 mean? The first number (10W) indicates cold-weather viscosity — lower is better for cold starts. The second number (40) indicates viscosity at operating temperature — higher provides more protection under load.
2003 Lexus GS 300/GS 430 Oil Change Interval & Maintenance Schedule
7,500
Recommended Miles
9
Recommended Months
Change oil every 9 months or 7500 miles, whichever comes first.
DIY vs. Professional Oil Change Cost Calculator
Estimate the exact cost of doing it yourself at home versus taking your vehicle to an independent quick-lube shop or the franchise dealership. (Pre-filled with this vehicle's capacity).
Oil change shopping list
What to Buy for This Oil Change
Engine oil
10W-40
Buy 1 x 5-quart jug plus 1 x 1-quart bottle. No leftover oil.
Capacity
6.0 qt
Add slowly near the end and re-check level after running the engine briefly.
Oil filter
Verify fitment
Filter (e.g. Fram PH6607A) can differ by engine, trim, and production date. Confirm before buying.
DIY Oil Change Tips for the Lexus GS 300/GS 430
Performing your own oil change on the 2003 Lexus GS 300/GS 430 can save $30–$60 per service. You will need: 6.0 quarts of 10W-40 full synthetic oil, a Fram PH6607A, a drain pan, and a Lexus-compatible oil filter wrench.
Allow the engine to warm up for 2–3 minutes before draining, then cool for 10 minutes. Torque the drain plug to manufacturer spec (typically 18–25 ft-lbs) to prevent leaks. Reset the oil life monitor if equipped after completing the service.
⚠ Reference Only: Always verify specifications with your official owner's manual. Oil specs may vary by trim level and engine variant. Consult a certified mechanic if unsure.
Estimated Change Cost
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Our technical specs are updated for 2026. If you noticed an error or need specialized engine data for your specific trim, contact our support team.
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