There are other things that may contribute to smoke at strart-up, so I wouldn't say that Arch Oil will necessarily fix that. However I used it through one winter oil change and was impressed with how quickly my truck passed through the extreme cold weather start-up roughness and noises, quieting the injectors and valve train. The warmer the temperatures the faster that takes place, or may be non-existent. However, Arch Oil is super expensive. I switched to Hot Shot Secret products and achieved the same results for far less money. Over my diesel ownership, one truck since 2005, I have used my share of snake oil, but Arch Oil and Hot Shot Secret do what they say. I have not used any Amsoil products, I hear good things but I'm happy with HSS. I have tried Lucas products and they may do exactly what they say but they don't quiet the engine like AO or HSS. This is all while using Shell Rotella full synthetic.