Facts About Oils and Filters
Ratings[edit]
When choosing oils the better the rating, generally the better the oil, and also the more expensive. Keep in mind even the Group II oils are probably still better then any oil that was made when your car was manufactured.
Basic explanation of ratings[edit]
| Group | Type |
|---|---|
| I | Mineral |
| II/II+ | Hydrocrack (Viscosity Index below 120) |
| III | Hydrocrack (VI above 120, mineral derived "Fake/Semi-Synthetic") |
| IV | Polyalphaolefin (Synthetic) |
| IV | Ester or any not fitting other groups |
Examples[edit]
Common products and their ratings (some may not be 100% accurate and may be blends between certain ratings).
| Redline | Group V Polyester |
| Motul 300V | Group V |
| Motul 8100 E-Tech 0W40 | Group IV/V Blend |
| Mobil 1 | Group IV |
| Motul 8100 X-Cess 5W40 | Group IV |
| Castrol SynTec 0W30 | Group III |
| Castrol Edge Sport 5W30/10W60 | Group III |
| Motul 4100 Turbolight | Group II |
Viscosity[edit]
The viscosity of the oil is one of the most important factors when deciding which oil to use. Newer engines use thinner oils because they have much smaller tolerances than older higher mileage engines. As rings, bearings, lifters etc wear these tolerances become larger, and a thicker oil can be used to take up the gap and reduce wear that would be caused if a thinner oil was used.
Grades[edit]
For an oil to be classed as say a 5W oil, it needs to be able to flow a certain amount at a low temperature. This first number is the oil's "cold" viscosity. The standards for measuring oil viscosity are determined by the SAE (Society of Automotive Engineers) and all engine oils use the SAE's standards for measuring viscosity.
The "W" suffix simply means that the oil is suitable for use during winter, meaning the oil will not become too thick under the lower overnight temperatures (usually only oils with a cold viscosity of 20 or lower will be classed for winter use, although I have seen a few 25W oils)
The second number is the oil's "hot" viscosity. This is a little harder to explain. Multigrade oils contain polymers which react under heat, and actually expand as they become hot. This is what prevents multigrade oils from becoming too thin under hot conditions. That's all well and good, but what does this second number have to do with that?
If you were to warm a monograde 40 weight oil to 100°C (210°F), it would be thinner than a 15 weight oil at cool temperature.
So, if you were to test a 15W-40 engine oil, it would have the viscosity of a monograde 15 weight oil at it's low temperature, and when warmed up it would have the viscosity of a monograde 40 weight oil at high temperature.
Filter Upgrade[edit]
The Ryco Z115 may be used as an upgrade from the normal Z145A on some engines due to it's larger size. The larger size of the filter increases oil capacity to almost exactly 5L. It may not fit on all engines due to its larger seal diameter (70mm as opposed to 63mm on the Z145A). Ensure that the seal seats properly if this filter is used to prevent oil from spewing everywhere. An oil filter sandwich plate may be used to get a bigger contact area to allow the filter to seal adequately.
Genuine Comparison[edit]
They both look the same externally. The Ryco was $7.70 from Burson, the Nissan $12 from Nissan.
They don't come out of the same factory, Ryco from South Africa, Nissan from Thailand.
Looking down the barrel of a used Ryco:
Looking down the barrel of a new Ryco, they've changed the design since last time, I don't know if the one I'm gutting came from South Africa or not, the old one looks the same as a Nissan inside, but the new one has a spiral design:
And the used Nissan, the different colour of the anti-drainback valve is visible.
Nissan guts left, Ryco guts right. Nissan is taller and bigger diameter, point to Nissan. The Nissan anti-drainback valve appears made out of silicone rubber or something a bit exotic, Ryco valve made of plain rubber and bigger, doubt it matters much either way.
Springs for bypass function visible either side. The Nissan spring is easily compressible. The Ryco spring is almost impossible to compress. So the Nissan would bypass a blocked filter element or sludgy oil much more easily than the Ryco. I would hope that my filter never got to that stage. Point to Nissan? Don't know.
The internal diameter of the Nissan filter element is smaller than the Ryco, point to Nissan again. Although the Ryco has more holes.
The Nissan filter is about 2200mm long and exactly 65mm wide - 143 000mm2. The Ryco filter is about 1900mm long and exactly 60mm wide - 114 000mm2. So Nissan filter has about 25% more area, point to Nissan. I clearly have no way of testing the efficiency or flow rate of the filter paper:
They are not identical internally, and the Nissan does look a bit better.
External links[edit]
- The Goods on Oils - SAU
- Motor Oil
- Z115 Info
- Z145A Info
- Some facts about oils
- Nissan v Ryco
- Groups
- Viscosity
Contributors: Session, Tobermory, rolls, blue