Snow foam is a product used to cover your car in a film of foam using a snow foam lance connected to a pressure washer. An alternative is to apply snow foam through a sprayer type bottle. Snow foam is designed as a wash agent and a pre-wash agent, Snow foam is used to soften dirt, car shampoo is not. Car shampoo can dry out and leave marks on the bodywork and windows which will need more work later on to remove. Snow Foam generally is cheaper than a good quality car shampoo. A dirty car is covered in particles, some stuck tightly to the surface. Scrubbing the car risks smearing these particles into the body work of your car.
Snow foam latches to the surface and helps to lift the dirt off of the surface thanks to its cleaning properties. When the foam is rinsed off, there will be much less grit on the outside, so you don’t have to worry as much about putting scratches in while washing. As the foam gently breaks down dirt and debris, your wash is much less abrasive. This is the most effective way to pre wash your car then you should get your bucket your clean sponge and good quality car shampoo.
A high quality car shampoo should foam a lot and contain a wax it is worth paying a bit more for a car shampoo with wax in as this is the protective layer for your cars paintwork and will leave your car with a showroom shine and protect from harsh grit and grime on todays roads. There is no better way to familiarise yourself with your car's bodywork and shape than feeling it and hand washing with a soapy sponge once you have lathered your baby up and scrubbed her good. Then just rinse off with a jet-washer removing all of the bubbles for a streak free finish.
In conclusion snow foam effectively is a pre-washing agent, this on its own sometimes is not enough so rather than comparing the 2 products they can be used in conjunction to leave a powerful long lasting showroom shine better than others.