Going to change the oil in my lawnmower myself. Per the user manual it specifies: SAE 30 detergent oil with API classification SF, SG, SH, SJ, SL or higher. At the hardware store I found multiple oil brands that fit the criteria. Some are SAE 5-30W, some SAE 10-30W, and one that simply says SAE …

Ok. It’s simple. Cold start regardless of air temperature. What in the world does “W”= Winter have to do with it???

[image] Tester: Thus 5W It’s not until the oil starts reaching the operating temperature does it start to thicken. Thus 30. It’s a viscosity index, not a viscosity. Cold 5W oil is actually thicker than hot SAE30. It doesn’t get thicker when hot, it simply doesn’t thin out as dramatically. …

Again simple. The W means that the oil will flow like a five weight oil down to zero degrees. Below that, the oil starts to thicken. Tester

Viscosity vs temperature of SAE 30 oil. [image] Viscosity vs temperature of 0W-30 oil [image]

Unbelievable…60 replies when one would do: “Use 30 weight.” Ya gotta love this site (not sarcasm…it’s why I stick around). ;-]

Most bike manufacturers specify motorcycle only multi grade oils that have additives that car oils don’t have.

For motorcycles that use wet clutches, look for “JASO-MA” on the oil can. I have used mostly Shell Rotella T6 5w40 in my last two motorcycles with excellent results, if you look at the label, it has the “JASO-MA” rating on the list of ratings. And it’s somewhat more economical than the oils that h…

@B.L.E . Thanks for the 2 graphs. Really interesting.

Is this a trick question? … lol … Since the lawnmower manufacture recommends SAE 30 oil, use that. I think SF grade is from the early 80’s, so any oil you buy now that’s SAE 30 should be ok.

5-W30 vs 10-W30 oil

Maintenance/Repairs

keith July 9, 2018, 2:45am 62

FYI, the W has not always meant winter. It used to mean weight. Here is a pretty good explanation, a little challenging to follow this late at night, but accurate as far as I can tell.

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5-W30 vs 10-W30 oil

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