My eldest son is a mechanic, he wears Jerzees sweatshirts. He used to wear green ones, which showed the oil marks, and I've washed them many times at 60 degrees without them suffering. I get lots of cotton things from Lands End as well, these tolerate tumble drying. Their polo shirts are fantastic, I've had some for years, always tumble dried, and they don't turn a hair, still the same shape.
Some of it is quite expensive, but If you sign up for their regular emails, they have regular sales and special offers, sometimes with as much as 70% off. So I get a shopping list together and then order when an offer is on.