Motor oil for new wood bed floor

[Skilsaw]

Have new red oak kit for 66 fleetside. I have read where people use used motor oil on their beds but I don’t want the darker look. I put a couple coats of new conventional oil on a scrap piece of oak, several days between coats to soak and dry. I like the look, kind of like a satin clear coat. It is smooth and dry feeling, don’t transfer when you rub on it. My worry is will it get tacky and messy if it sits out in the hot sun for awhile? If anyone has done this how did it hold up and would you do it again? Would I be better off to get linseed or tung oil or something else?

Also I was thinking of painting the underside and edges that don’t show. Is that a good idea or just oil the whole thing?

Thanks