2012 Nissan Quest
Used‑Oil Analysis & Follow‑Up Plan
Lab sample dated July 12, 2025. AMSOIL Signature Series 5W‑30 with an Ea15K12‑EA filter had 3,000 miles and 32 months in service at sampling. Given the low use, I plan to run this oil and filter to a three‑year interval.
The Quest sees limited driving due to other issues: AC compressor replacement, engine mounts, front wheel bearings, and CVT problems (slipping, stalling, and shuddering from a stop).
I performed regular CVT drain‑and‑fills with NS‑2 fluids at oil changes. Fluid was drained via the plug or siphoned, refilled through the dipstick tube, and the level was set at the correct temperature range. I first used AMSOIL 100% Synthetic CVT Fluid in November 2022. We replaced the Quest as our primary vehicle shortly after because of the non‑engine issues, and since then have used it for local cargo trips. The engine runs well; other systems have deteriorated. Purchased in 2015 at 60,000 miles; now at 162,000 miles, which is acceptable for a Nissan CVT with regular service. Service life may have been longer had AMSOIL CVT fluid been used from the start.
In June 2025 I changed the CVT fluid again with AMSOIL 100% Synthetic CVT Fluid. Slipping was greatly reduced. Before the change it shuddered and could stall when launching, and could not climb an incline from a stop. After the change it accelerates almost normally with only slight shuddering and no stalling on inclines. I will change the CVT fluid again at the next oil change and reassess.
What I Did and Why it Matters
I installed AMSOIL Signature Series 5W‑30 (ASL) and an Ea®15K12‑EA filter at 159 000 miles in Nov 2022 (oil capacity 5 qt). Nissan lists a 7 500‑mile / 6‑month oil‑change interval for normal service on the Quest. Because I drive only ~1 500 miles per year, time—not mileage—forces my oil change. A used‑oil analysis lets me stretch drains safely and reduce waste.
Key Lab Numbers vs. Industry Guidelines
Iron — 12 ppm · Well under the ~100 ppm caution line; wear remains very low.
Fuel dilution — 1.0 % · Safely below the 2.4 % limit for gasoline engines.
Oxidation — 40 abs/cm · At the industry watch level (> 30 abs/cm) but not yet thickening the oil.
TBN (base reserve) — 4.5 mg KOH/g · Above the 3 mg change‑oil trigger; plenty of additive left.
Viscosity @ 100 °C — 10.5 cSt · Smack in the SAE 30 window (9.3 – 12.5 cSt); no shear or thickening.
Silicon — 17 ppm · Indicates good air filtration (< 20 ppm target).
Ea®15K12‑EA filter efficiency — 99 % @ 20 µm · Premium filtration keeps wear metals down.
Take‑away: Wear metals are low, viscosity is on‑grade, TBN is healthy and contaminants are minimal. Oxidation has reached the caution line but is not yet affecting viscosity. The lab rated the sample “NORMAL – oil suitable for continued use.”
How Long Can I Safely Run This Oil?
Base Reserve Trend – Fresh Signature Series starts near 12 TBN ; at 4.5 after 32 months, linear projection reaches the 3 TBN limit in roughly 10 more months.
Oxidation Ceiling – Industry warns of rapid viscosity rise above 30‑40 A/cm; I am at the upper edge now, so another ~2 000 miles (about one more driving season) is prudent.
Filter Rating – The Ea15K12‑EA is designed for 15 000 miles or one year; it is time‑expired even though mileage is low.
My Plan:
Replace oil and filter at 5 000 total miles on the fill OR by November 2025, whichever comes first. This keeps TBN above 3, oxidation below critical levels.
What I Will Install Next
The same thing I use now.
Oil: AMSOIL Signature Series 5W‑30 100% Synthetic Motor Oil – guaranteed protection for up to 25 000 mi or one year under normal service.
Filter: AMSOIL Ea®15K12‑EA Oil Filter – 99 % efficient at 20 µm to keep wear metals low.
Why AMSOIL Works for Low‑Mileage Drivers
Signature Series offers 28 % more acid‑neutralizing power than Mobil 1, giving extra capacity for long time‑based drains.
The oil’s 25 000‑mile / 1‑year guarantee ensures peace of mind even if my usage pattern changes.
Full‑synthetic base stocks resist fuel dilution and oxidation better than conventional oils, protecting the Quest’s 3.5 L VQ35DE in hot Tennessee summers.
Quick Reference
Vehicle: 2012 Nissan Quest, 162 000 mi
Sample date: 12‑Jul‑2025
Miles on oil: 3 000
Oil / Filter used: AMSOIL Signature Series 5W‑30 + Ea15K12‑EA
Next service: November 2025 or 5 000 mi on oil, whichever comes first
