If you wash your truck at home, you can claim the cost of household water and detergent for washing the truck as a business expense at tax time. Be sure to document the date and time. If you use commercial truck stop washes, that cost is deductible as well.
This tip comes from the 2012 Partners in Business manual, produced by Overdrive and the consultants at ATBS (atbsshow.com). The program is sponsored by Shell Lubricants, Ryder System and Bridgestone Bandag Tire Solutions. See OverdriveOnline.com/pib for information.