Some of what is done to underground units, remember we work in a confined atmoshphere so engine management is critical to healthy work. http://www.deep.org/reports/mechanicsman.pdf Again: Western Canadians should try Federated Co-op's Diesel Fuel. Probably the best fuel in North America because it starts out as a sweet crude put through a great refinery. email me for extra details like Cetane... 2. Cetane Number >46, offering: - More complete combustion/lowering exhaust emissions. - Reduction in white smoke (cold starts). - Lower engine noise. - Better fuel economy. - Reduced warm-up time, misfire and improved low temperature starting. 3. Premium Additive Package offering: - Clean Injectors/reduced maintenance. - Reduced exhaust emissions. - Black smoke reduction. - Improved fuel economy. - Better water shedding properties, better corrosion performance and better fuel stability.