That will last a good long while.I used 1/2 diesel and 1/2 used motor oil on my utility trailer/car hauler after I replaced several boards. It’s only been 6-8 months though. Several coats (3-4 on the new stuff) and that old wood drank it right in. Trailer looks better than it did when it was new. We’ll see how it holds up over time
See my above post about the same.