❄️ CCS apparent viscosity (low temp.)
Determination of apparent viscosity of engine oils at low temperatures (from −5°C to −40°C) using Cold Cranking Simulator. Key parameter for SAE classification.
Overview
Cold Cranking Simulator (CCS) is a laboratory device simulating conditions in internal combustion engine during cold start. It measures apparent viscosity of engine oil at high shear stress (~50,000 Pa) and high shear rates (~10⁴–10⁵ s⁻¹) at temperatures from −5°C to −40°C. CCS viscosity correlates with oil behavior during starter cranking in frost — lower CCS viscosity means easier engine start.
CCS test result is one of two low-temperature parameters defining SAE winter viscosity grade (e.g. 0W, 5W, 10W, 15W, 20W, 25W) according to SAE J300 specification. For example, SAE 5W grade oil must have CCS viscosity ≤6,600 mPa·s at −30°C. Second low-temperature parameter — pumping viscosity (MRV, ASTM D4684) — evaluates oil's ability to reach oil pump.
CCS test is mandatory for every engine oil offered on market. It is performed by refinery laboratories, oil manufacturers (Shell, Castrol, Fuchs, Orlen Oil), research institutes (INiG-PIB, ITS) and accredited laboratories in homologation and control testing. CCS result determines under what climatic conditions oil can be safely used.
CCS device was developed by ASTM in cooperation with SAE and is produced mainly by Cannon Instrument Company (USA). Contemporary models (CCS-2100, CCS-G6) enable automatic analysis of up to 30 samples without operator supervision.
Method principle
Oil sample is placed in annular gap between rotating rotor and stationary stator, cooled to set test temperature. Rotor is driven by electric motor with constant torque. Oil viscosity causes resistance to rotation — more viscous oil makes rotor rotate slower. Rotor rotational speed is measured and converted to apparent viscosity (in mPa·s) based on calibration with reference oils of known CCS viscosities (e.g. Cannon CL-series). Measurement takes several tens of seconds after reaching stable temperature.
Applications
- Classification of engine oils according to SAE J300 (winter grades 0W–25W)
- Quality control of engine oils in production
- Homologation testing of oils for passenger and truck engines
- Assessment of base oils for engine oil formulations
- Development studies of new oil formulations (R&D)
- Control of engine oils in service (oil analysis)
- Verification of ACEA and API specifications (A3/B4, SN Plus etc.)
Key parameters
| Parameter | Value |
|---|---|
| Viscosity range | 900–25,000 mPa·s |
| Temperature range | −5°C to −40°C (typically −10 to −35°C) |
| Shear rate | ~10⁴–10⁵ s⁻¹ |
| Shear stress | ~50,000 Pa |
| Repeatability | ±5.2% of mean value |
| Reproducibility | ±14.8% of mean value |
Standard
- Standard number
- ASTM D5293-20
- Title (PL)
- Lepkość pozorna olejów silnikowych i baz olejowych w temperaturze od −10°C do −35°C za pomocą symulatora rozruchu zimnego (CCS)
- Title (EN)
- Standard Test Method for Apparent Viscosity of Engine Oils and Base Stocks Between –10°C and –35°C Using Cold-Cranking Simulator
Step-by-step procedure
1. Apparatus check
Turn on CCS min. 30 min before measurement. Check refrigerant level. Verify measurement cell temperature (calibrated thermometer).
2. Calibration
Measure viscosity of CL reference oil appropriate for measurement range. Result must be within ±5% of certified value. If deviation — recalibrate.
3. Sample preparation
Bring engine oil sample to room temperature. Mix by inverting container several times. Do not heat above 50°C.
4. Measurement cell filling
Draw ~5 mL oil into syringe. Introduce oil into annular gap of CCS measurement cell. Avoid air bubbles.
5. Test temperature setting
Select measurement temperature according to declared SAE grade: 0W → −35°C, 5W → −30°C, 10W → −25°C, 15W → −20°C, 20W → −15°C, 25W → −10°C.
6. Cooling and measurement
CCS cools cell to set temperature (time ~5–10 min). After stabilization, starts rotor with constant torque. Measures rotational speed and calculates viscosity. Measurement time ~30 s.
7. Result reading
Read CCS apparent viscosity in mPa·s. Compare with SAE J300 limit for declared grade (e.g. 5W: max 6,600 mPa·s @ −30°C).
8. Cell cleaning
Rinse measurement cell with naphtha (3× 5 mL each), then hexane (2× 5 mL). Dry with air stream. Cell ready for next sample.
9. Measurement repetition
Perform minimum 2 measurements for each sample. Difference between repetitions ≤5.2% of mean value (repeatability criterion).
10. Final verification
At end of series measure CL reference oil again. Result must confirm calibration stability (±5% of certified value).
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Cold Cranking Simulator CCS | Cannon CCS-2100, Cannon CCS-G6 (automatic, up to 30 samples) | 150,000–350,000 PLN |
| Cooling system | Built-in cascade compressor or external cryogenic bath (liquid nitrogen) | built into CCS |
| CCS viscosity standards | Cannon CL-series (CL130, CL250, CL500, CL3500) — certified reference oils | 300–600 PLN / 500 mL |
| Dosing syringes | Plastic syringes 5–10 mL for filling measurement cell | 50–100 PLN / 100 pcs |
| Cleaning solvent | Naphtha or hexane for rinsing cell between samples | 30–80 PLN / L |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| Reference oil CL130 | — | Cannon CL130, certified CCS viscosity in range −5°C to −35°C, 500 mL |
| Reference oil CL250 | — | Cannon CL250, medium viscosity range, for calibration verification |
| Reference oil CL3500 | — | Cannon CL3500, high viscosity range (20W–25W grade oils) |
| Naphtha (for cleaning) | 8008-20-6 | Solvent for rinsing measurement cell after each sample |
| Hexane (for final cleaning) | 110-54-3 | For final rinsing and drying of cell, evaporates quickly |
Health and safety (OHS)
- Low temperatures (down to −40°C) — frostbite risk, do not touch metal cell parts with bare hands
- Naphtha and hexane — flammable, vapors form explosive mixtures, work in ventilated room
- Hexane — harmful by inhalation (H304, H361f), neurotoxic with chronic exposure
- Engine oils — may contain irritant additives, use protective gloves