No, using full-strength Simple Green All-Purpose Cleaner on car paint is not recommended. While it's a powerful degreaser for engines and wheels, its alkaline pH can damage clear coats and painted surfaces over time. Automotive paint requires pH-balanced cleaners with lubricants to safely lift dirt without causing micro-scratches or dulling the finish.
The primary risk comes from the product's chemical composition. Simple Green is designed to cut through tough grime and grease, which is too harsh for clear coats. Repeated use can strip protective waxes and sealants, and in some cases, can even begin to degrade the clear coat itself, leading to a loss of gloss and potentially causing the paint to become more susceptible to UV damage and oxidation.
For routine car washing, you should always use car wash soap specifically formulated for automotive finishes. These soaps are pH-neutral and contain lubricating agents that help the wash mitt glide over the surface, encapsulating dirt to prevent swirl marks. They effectively clean without compromising the paint's protective layers.
Here is a comparison of typical cleaners and their suitability for car paint:
| Cleaner Type | pH Level | Key Ingredients | Primary Use Case | Risk to Car Paint |
|---|
| Car Wash Soap | Neutral (~7.0) | Surfactants, lubricants, gloss enhancers | Washing exterior painted surfaces, glass, trim | Very Low when used as directed |
| Simple Green (Diluted) | Alkaline (~8.5-9.5) | Surfactants, solvents, water softeners | Engine bays, wheel wells, tires, interior plastics | Moderate; can strip wax, dull finish if misused |
| Simple Green (Full-Strength) | Highly Alkaline (~10.5+) | Concentrated surfactants and solvents | Heavy-duty industrial/degreasing tasks | High; can damage clear coat, cause etching |
| Dish Soap | Alkaline (~8.0-10.0) | High-strength degreasers (e.g., SLS) | Cutting grease on dishes | High; strips wax/sealants, degrades protection |
If you absolutely must use Simple Green on a painted area—for instance, to remove a stubborn, sticky substance like tree sap or tar—it is critical to dilute it significantly (a ratio of 1:10 or even 1:15 with water is often suggested) and to use it for spot cleaning only. Immediately rinse the area thoroughly and follow up by applying a fresh layer of wax or sealant to restore protection.
