A method of operating an engine comprises introducing into a cylinder volume a non-compression-combustible fuel, such as natural gas, a compression-combustible fuel, such as diesel, and an oxidant and mixing the components for greater than about 275 microseconds, prior to compression combusting the compression-combustible fuel. The mixing may be done such that the two fuels are at least partially homogenized in the cylinder volume. By mixing, or premixing, the two fuels prior to combustion, the compression-combustible fuel is then simultaneously combusted via compression at multiple ignition points in the volume. The second, non-compression-combustible fuel is ignited in response to the combustion of the first fuel. An engine that enables the various methods is also disclosed.