Can I Use Simple Green To Wash My Car? | Paint Protection

You probably have a bottle of Simple Green under the kitchen sink or in the garage, used for everything from grease stains to engine parts. When the car wash soap runs out, it’s easy to reach for that familiar green liquid and assume it’s fine for the paint.

But here’s the catch: standard Simple Green All-Purpose Cleaner was designed for heavy-duty degreasing, not automotive finishes. Many car enthusiasts and detailers warn that it strips wax and may damage clear coat over time. Simple Green does make a dedicated product specifically for cars — the answer comes down to which bottle you grab.

What Simple Green Products Are Safe For Car Paint

The company produces two distinct product lines that matter here. Simple Green All-Purpose Cleaner is the classic concentrate sold for all-purpose cleaning. The manufacturer states it’s “gentle enough for delicate car surfaces,” but they also market a separate product called Simple Green Car Wash (and Simple Green Wash & Wax) that is specifically formulated for automotive paint.

The dedicated Car Wash product is pH-balanced and designed to clean without stripping wax or harming clear coat. For the Car Wash concentrate, the recommended dilution is 1 ounce per gallon of water. In contrast, the All-Purpose Cleaner is alkaline — it’s a degreaser first, and that chemistry can be too aggressive for wax and clear coat when used routinely.

Why The Confusion Sticks

The “all-purpose” label makes people think it works on every surface, including painted panels. The logic sounds reasonable: if it’s safe enough for kitchen counters, why not the car? But automotive paint is different — it’s covered by a layer of clear coat, and wax provides a protective barrier. Harsh cleaners can compromise both.

• pH chemistry matters: Most dedicated car wash soaps are pH-neutral (around 7). Simple Green All-Purpose Cleaner is alkaline, which helps it cut grease but also attacks wax. pH-neutral formulas clean without stripping protection.
• Wax is sacrificial: Car wax is designed to be somewhat durable, but alkaline cleaners can break it down quickly. Forum users report that even a single wash with all-purpose Simple Green can leave paint feeling stripped of protection.
• Clear coat is not indestructible: Repeated use of harsh cleaners can gradually degrade the clear coat layer, leading to dullness or etching. Detailers on BobIsTheOilGuy warn that Simple Green may remove essential oils from clear coat over time.
• Manufacturer’s own product lineup: Simple Green sells a dedicated car wash for a reason — they know the all-purpose formula isn’t ideal for paint. Using the wrong product voids the convenience of a one-bottle solution.
• One-time use vs. habit: Using all-purpose Simple Green once, heavily diluted and followed by a thorough rinse and wax, may not cause immediate damage. But making it your regular wash routine increases risk.

The bottom line of this section: if you care about wax longevity and paint appearance, reach for a dedicated car wash product rather than the all-purpose cleaner.

How Simple Green Wash & Wax Compares

Simple Green’s Wash & Wax combines a gentle cleaner with wax protectants. It’s designed to clean without stripping existing wax and to leave a light layer of protection behind. The manufacturer’s product guide for simple green wash & wax describes it as tough on dirt and bugs but gentle on delicate surfaces.

For comparison, here’s how the main options stack up for routine car washing. The table uses manufacturer data and common forum observations — individual results vary, but these are the typical expectations.

The key takeaway: pH-balanced products — whether from Simple Green’s car wash line or another brand — are the safest bet for regular washes. Alkaline products like the all-purpose cleaner or dish soap should be reserved for non-painted surfaces or used only if you plan to re-wax immediately.

Safe Alternatives For Washing Your Car

If you don’t have dedicated car wash soap on hand, several household items can work in a pinch. The safest options are those that are pH-neutral and free of strong detergents or abrasives. Many detailers agree that the goal is to clean without stripping wax or damaging clear coat.

1. Simple Green Car Wash (dedicated product): This is the easiest swap if you already buy Simple Green. Just pick up the car-specific product and follow the 1-ounce-per-gallon dilution. It works as well as any mainstream car soap.
2. Baby shampoo: Mild and pH-friendly, baby shampoo is a widely recommended alternative. Use a small squirt per bucket of water — it lathers gently and doesn’t attack wax. Rinse thoroughly.
3. Hand soap (liquid dish soap not recommended): A mild liquid hand soap is less harsh than dish soap. Many detailers say hand soap won’t strip wax the way dish soap does, though it may not clean as effectively on heavy grime.
4. Snow foam (if you have a pressure washer): Pre-foaming with a pH-neutral snow foam loosens dirt before you touch the paint. This reduces the risk of scratches, especially when combined with a gentle shampoo.

Whichever alternative you choose, always use two buckets (one for soapy water, one for rinsing your mitt) and a microfiber wash mitt to minimize swirl marks. Follow up with a quick wax if you suspect any protection was removed.

What Car Enthusiasts Really Warn About

The most vocal warnings about Simple Green come from long-time car enthusiasts and detailers. On forums like Corvetteforum, users share direct experience: the all-purpose cleaner removes wax, and if used without re-waxing, leaves paint exposed to UV and contaminants.

One Corvetteforum thread specifically discusses forum warnings about wax stripping after using Simple Green as a car wash. Participants note that the cleaner “eats the wax” and advise that if you do use it, you must dilute heavily, rinse thoroughly, and apply fresh wax immediately.

Other forums, including BobIsTheOilGuy and Tacoma World, echo similar cautions. A BobIsTheOilGuy user states that repeated use can damage clear coat by removing essential oils. The Tacoma World thread adds a warning about using Simple Green on aluminum parts — the manufacturer’s own FAQ advises against it for that material.

While these are forum anecdotes rather than controlled studies, the sheer volume of similar reports from experienced car owners makes the pattern hard to ignore. The safest approach is to treat the all-purpose cleaner as a degreaser for engine bays and wheels — not for paint.

The Bottom Line

Using standard Simple Green All-Purpose Cleaner for routine car washes is not recommended. It can strip wax and may damage clear coat over time. If you want a Simple Green product for your car, choose the dedicated Car Wash or Wash & Wax — they’re pH-balanced and safe for paint. For a one-time emergency wash, you can use a heavily diluted all-purpose cleaner, but plan to re-wax the entire car afterward.

For personalized advice on your vehicle’s finish, consult a professional detailer or check your owner’s manual for paint care recommendations specific to your car’s clear coat and wax type.