HHO Carbon Clean Systems uses on-demand hydrogen to remove harmful carbon buildup in internal combustion engines (gas and diesel). (800) 279-6343 www.hhoccs.com www.hhofranchise.com ✅ 9% savings on average in fuel savings ✅ 70% reduction in emissions ✅ 2-7% improvement in HP ✅ Up to 90% reduction in DPF Pressure. HHO is a mobile preventative maintenance franchise offering carbon cleaning services.