HD stands for high detergent. As to lawn mower use, just fine if it's a
four stroke. I wouldn't use HD oil in a two stroke.
Christopher A. Young
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My son was helping clean up the garage and decided to combine some half
empty containers of oil. He mixed a small amount of SAE 30 HD into a
larger container of SAE 30. Probably less than 25% HD.
The only thing I use SAE 30 for is my lawnmower. A little SAE 30 HD
mixed with the SAE 30 isn't going to make any difference is it?