what oil?

[aaronng]

10w is the thickness of the oil during start-up of the car, 30 is during operating temperature.

10w is the SAE equivalent viscosity at -18 C. Since we don't have -18 C weather here, the lower rating is not really representative of cold start viscosity in Australia.

[aaronng]

aarong

i thought 10w is the thickness and 30 is the working temp?
let me check

this is what i found

The SAE designation for multi-grade oils includes two grade numbers; for example, 10W-30 designates a common multi-grade oil. Historically, the first number associated with the W (again 'W' is for Winter, not Weight) is not rated at any single temperature. The "10W" means that this oil can be pumped by your engine as well as a single-grade SAE 10 oil can be pumped. "5W" can be pumped at a lower temperature than "10W" and "0W" can be pumped at a lower temperature than "5W". The second number, 30, means that the viscosity of this multi-grade oil at 100°C (212°F) operating temperature corresponds to the viscosity of a single-grade 30 oil at same temperature. The governing SAE standard is called SAE J300. This "classic" method of defining the "W" rating has since been replaced with a more technical test where a "cold crank simulator" is used at increasingly lowered temps. A 0W oil is tested at −35 °C (−31 °F), a 5W at −30 °C (−22 °F) and a 10W is tested at −25 °C (−13 °F). The real-world ability of an oil to crank in the cold is diminished soon after put into service. The motor oil grade and viscosity to be used in a given vehicle is specified by the manufacturer of the vehicle (although some modern European cars now make no viscosity requirement), but can vary from country to country when climatic or mpg constraints come into play.

What you found there actually contradicts what you said.

[dahon]

the first number is the cold start viscosity rating the oil has, the lower the number the faster it flows at cold start (ie better - less thick)
the second number is the operating temperature viscosity of the oil.. dependent on operating conditions you will be running at usually... 30 is within reason... (the higher the number the thicker the oil will be)


"At the low-temperature end, oil has to be resistant to thickening so that it flows more easily to all the moving parts in your engine. Also, if the oil is too thick the engine requires more energy to turn the crankshaft, which is partly submerged in a bath of oil. Excessive thickness can make it harder to start the engine, which reduces fuel economy. However, synthetic oils can be formulated to flow even more easily when cold, so they are able to pass tests that meet the 0W rating.

Once the engine is running, the oil heats up. The second number in the viscosity rating--the "40" in 10W-40, for example--tells you that the oil will stay thicker at high temperatures than one with a lower second number--the "30" in 10W-30, for example. What's really important is that you use the oil viscosity your car's owner's manual recommends."

sounds about right?

[aaronng]

the first number is the cold start viscosity rating the oil has, the lower the number the faster it flows at cold start (ie better - less thick)
the second number is the operating temperature viscosity of the oil.. dependent on operating conditions you will be running at usually... 30 is within reason... (the higher the number the thicker the oil will be)


"At the low-temperature end, oil has to be resistant to thickening so that it flows more easily to all the moving parts in your engine. Also, if the oil is too thick the engine requires more energy to turn the crankshaft, which is partly submerged in a bath of oil. Excessive thickness can make it harder to start the engine, which reduces fuel economy. However, synthetic oils can be formulated to flow even more easily when cold, so they are able to pass tests that meet the 0W rating.

Once the engine is running, the oil heats up. The second number in the viscosity rating--the "40" in 10W-40, for example--tells you that the oil will stay thicker at high temperatures than one with a lower second number--the "30" in 10W-30, for example. What's really important is that you use the oil viscosity your car's owner's manual recommends."

sounds about right?

In simple terms, yes, that's how viscosity ratings can be interpreted. However, I wouldn't trust everything that source says as gospel because they don't even have the understanding of how the crankcase and crank works. The crank is never meant to be submerged in oil.

[dahon]

ahh kz ic ic bloody intardnet
but the jist of the oil thing i wrote before then sounds right right? thats what i was led to believe by my manual/the book thingys at big w... hehehe

but anyways for na-118: get honda FEO 10w-30 & honda OEM oil filter man... plus the sump plug washer..
35ish all up!

[tiksie]

While there is already a thread on this and many more, whats the recommended oil for a 1.3L carby EG Breeze ?

Motor has got 203xxx kms on it though very healthy, no leaks doesn't blow smoke or anything or burn oil.