When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
the fill plug is a 14mm, so you can use an open 14mm wrench. always remove the fill plug first, because if it sticks you can't refill it!
I've always leaned toward the Crescent because I have one that is considerably longer than any of my open-end 14mm wrenches. Makes for easier access & less sticking potential.