Precision Engineering and Veteran Owned Integrity. At Bitterroot Diesel Performance, we bridge the gap between traditional craftsmanship and cutting edge innovation. As a veteran owned OEM and contract manufacturer, we specialize in high-precision solutions for the automotive industry, most notably as the leader in premium vegetable oil fuel conversions for diesel vehicles. From bespoke machining to sustainable fuel technology, our mission is simple: deliver excellence that exceeds every standard.