The right kind of cleaning power!
There are two reasons why steam cleaning units aren’t ideal for a steam car wash. Firstly, these units lack the sustained cleaning power required to clean the entire vehicle. Although they are great for doing spot-cleaning interiors, they aren’t good enough for washing an entire car or truck. Another problem with dry steam cleaning units is the fact that they only emit about 5% moisture. They may be very effective in melting and dissolving certain stains and sedimentation, however, the user needs to use a brush to remove dirt. This repeated wiping can cause scratches to the paint job.
The best units for a mobile car wash are power washers with pressure levels of 1500 psi or less. These units should also come with water flow rates of 0.5 GPM that offer effective cleaning without hurting the body of the vehicle. A number of these kinds of best steam car wash units are available from some of the best companies, such as Daimer® http://www.daimer.com/car-detailing-mobile-car-wash/