GSedan

Maintenance schedule

1. 1
   Every 5,000 miles or 6 months, whichever comes first Engine oil and filter change — full synthetic 5W-30

   The VQ35HR's VTC actuator and VVEL solenoids are oil-pressure dependent. Extended drain intervals cause varnish buildup that triggers timing rattles and codes. Do not stretch to the 10,000-mile interval even if the monitor allows it on this age of vehicle.

2. 2
   Every 40,000–50,000 miles Transmission fluid change (RE7R01A)

   Infiniti often listed this as 'lifetime' fluid, but in practice 40–50k drain-and-fill intervals keep the valve body clean and prevent shudder. Use Nissan Matic-S or equivalent specification fluid.

3. 3
   Every 50,000 miles or 5 years Coolant flush

   The VQ35HR aluminum block is sensitive to degraded coolant chemistry. Low silicate or OAT coolant of the correct type prevents water pump and thermostat corrosion.

4. 4
   Every 60,000 miles Spark plugs (platinum/iridium)

   The V6 has rear bank plugs that require intake manifold removal — labor adds up quickly. Do all 6 at once to avoid doing the job twice. Use NGK or Denso OEM-spec plugs.

5. 5
   Every 2 years regardless of mileage Brake fluid flush

   Brake fluid absorbs moisture over time. In Wisconsin freeze-thaw cycles, moisture-saturated fluid can cause corrosion inside calipers and the ABS module.

6. 6
   Every fall before winter — annually Underbody and brake line inspection

   Wisconsin road salt aggressively attacks brake lines, fuel lines, and the rear subframe on these cars. Catching surface rust before it becomes structural saves hundreds over thousands of dollars.

7. 7
   Every 30,000–45,000 miles Differential fluid change (rear)

   RWD cars are often overlooked here. The rear differential fluid degrades and, on an open diff, causes wear. Check for any signs of leaking at the pinion seal while servicing.

8. 8
   Every 15,000–20,000 miles or annually Air filter replacement

   Wisconsin road dust and debris clog the filter faster than the manufacturer's extended interval suggests. A clean filter protects the mass airflow sensor and maintains fuel economy.

Always defer to the manufacturer's service manual for warranty-mandated intervals.

Cost of ownership

A well-maintained 2008 G35 Sedan is a relatively affordable luxury RWD car to own — provided you don't defer maintenance. Routine costs are moderate, but the rear bank spark plug job (every 60k mi) is a $350–$550 shop bill due to labor, and any timing system work climbs fast. Plan on $700–$1,000/year in a good year, $1,600+ if suspension, transmission, or timing components need attention. Budget separately for undercoating/rust mitigation if the car has lived in salt country.