Says ‘engines’ on the bottle
The boy brought the smaller bottle back to his friend and asked him if he could read what it said. They still had a long drive ahead of them, so they decided to check out what was on the back of the bigger bottle before leaving.
To their delight, the back of the WD-40 bottle read “engines.” They were certain it would work on one of their automobiles since they knew the product was meant to be used on engines.