Lestoil and a toothbrush. Perfect combo for oil stains. Don't heat dry... just hang dry and reassess the stains and repeat as needed.

Andrew

Jesse I asked my wife what she has been using when I get oil/grease on my clothes. For minor issues she first tries Dawn dishwashing but for more serious stains she says to lay the shirt out and spot treat with Pinesol. Let the liquid work into the fabric then wash.

She is a chemist by training and knows her stuff!

Depending on what the shirt is made of, acetone works wonders at getting oil and grease out of many fabrics. I have used it to get forklift mast grease out if a really nice dress shirt.

Shout Advanced in the aerosol can works very good on oily stains. Even really bad stuff like fifth wheel grease.

Taking it to a cleaner and asking for an assist is a good solution.

Those are the instances where wife pulls out the "you were wearing THAT shirt while doing this?" look. And she's not wrong.... but sometimes you don't see the issue coming.

Spraying Simple Green directly on oil spots and letting the clothes sit for an hour or two before washing in hot water works for me.