Wash and Decontamination
P&S Pearl vs Adam's Car Shampoo
Two pH-neutral concentrates sold by the gallon. One costs about half as much per ounce; the other is the one that states it will not strip your protection.
By Sawyer V. · Last verified 2026-09-10
We have not tested any of this. Everything below is compiled from published manufacturer specifications, and the arithmetic is printed so you can check it. This page carries affiliate links: if you buy through one we earn a commission at no extra cost to you, and it does not change the order of the picks. Full disclosure.
| # | Pick | Best for | Score | Price |
|---|---|---|---|---|
| 1 | P&S Pearl Auto Shampoo Concentrate P&S | The cheapest gallon of professional soap here | 7.3/10 | Check price on Amazon |
| 2 | Adam's Car Shampoo Adam's Polishes | The default pH-neutral soap, bought by the gallon | 6.2/10 | Check price on Amazon |
No live price is currently verified, so every button here reads Check price rather than a number we cannot stand behind. Why we do it that way.
Side by side
| P&S Pearl | Adam's Car Shampoo | |
|---|---|---|
| Gallon price | $21.68 | $39.99 |
| Per ounce | About 17 cents | About 31 cents |
| Sizes | Quart / gallon | 16 oz / gallon / 5 gallon |
| pH | Stated pH-balanced; no figure | Stated pH-neutral; no figure |
| Effect on protection | Not stated | Stated not to remove wax, sealant or coating |
| Sunlight | Not stated | Stated safe in sunlight |
| Other claims | 100% biodegradable; hand wash and dilution systems | Concentrated |
| Dilution ratio | Not published | Not published |
Half the price per ounce
Pearl is about 17 cents an ounce by the gallon and Adam’s about 31. Neither publishes a dilution ratio, so the per-ounce gap is only a per-wash gap if you use the same amount of each, and nobody tells you what that amount is. The car wash soap roundup covers that missing figure.
What the extra $18 buys
Two statements. Adam’s say their shampoo will not remove existing wax, sealant or coating, and that it can be used in direct sunlight. P&S say neither on the Pearl listing; they say it is pH-balanced and 100% biodegradable, and made for hand washing and dilution systems.
Who each is built for
Pearl comes from a line sold by the case to professional shops, which is why it is cheap and why the documentation is written for them. Adam’s is sold to the enthusiast washing one car, and its claims are the ones that person asks about.
Who should buy which
- Lowest cost per ounce, several cars a week: P&S Pearl, $21.68 a gallon.
- A waxed or coated car you want the soap to leave alone: Adam's Car Shampoo, $39.99 a gallon.
- Washing in the sun: Adam's, the one that states it is sun-safe.
Every pick, with the working
Each entry lists the specifications the maker publishes, the axis scores those specifications produce, and what you give up. Rows that read “Not published” are not omissions on our side: they are figures the maker will not commit to in writing, and they cost the product points on the transparency axis.
Our pickThe cheapest gallon of professional soap here
P&S Pearl Auto Shampoo Concentrate
P&S
A gallon at $21.68, pH-balanced and stated to be 100% biodegradable, from a line that exists because professional shops buy soap by the case. At 17 cents an ounce it is half the price of anything else in this list.
- Sizes
- 1 quart / 1 gallon
- pH
- Stated pH balanced; no figure published
- Biodegradability
- Stated 100% biodegradable
- Stated uses
- Hand wash and dilution systems
- Dilution ratio
- Not published
- Foam cannon dose
- Not published
What it does well
- $21.68 a gallon works out at $0.17 an ounce, the cheapest here by a wide margin
- Stated 100% biodegradable and pH balanced
- Explicitly stated for hand washing and dilution systems alike
Who it is not for
- No dilution ratio published on the listing, which is the figure a concentrate lives or dies by
- No pH figure published
- Packaging and documentation are aimed at shops, not at a person with one car
How this score was calculated
- Protection claimdropped
- Nothing in this category is bought on how long it lasts, so the axis is dropped and the other weights are re-normalized.
- Capabilitydropped
- P&S does not publish a figure for published dilution on this product, so the axis is dropped and the remaining weights are re-normalized.
- Cost per ounce10.0/10, weight 16%
- $21.68 for 128 oz works out at $0.17 an ounce, scored against a band of $0.35 (good) to $1.60 (expensive) for a wash soap.
- Price against the ceiling5.2/10, weight 14%
- A listed $21.68 against the $45 one upgrade in this category realistically tops out at. A list price captured on the compile date, not a live price and not what you will pay.
- Written commitmentdropped
- P&S publishes no warranty term on this product's own page, so the axis is dropped. On a tool that is worth noticing, and it costs the product points on transparency instead.
- Spec transparency6.7/10, weight 18%
- 4 of the 6 specifications we went looking for are published by P&S. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $21.68 per The Rag Company, 1 gallon, captured on the compile date below. Not a live price and not what you will pay — the button is where the real number is.
Specifications from The Rag Company's P&S Pearl listing, compiled September 8, 2026.
2The default pH-neutral soap, bought by the gallon
Adam's Car Shampoo
Adam's Polishes
A pH-neutral concentrate Adam's states will not remove existing protection and can be used in sunlight. Bought as a gallon it is about 31 cents an ounce, which is the cheapest way to stop worrying about whether your soap is stripping the coating you just paid for.
- Sizes
- 16oz / gallon / 5 gallon
- pH
- Stated pH neutral; no figure published
- Effect on protection
- Stated not to remove existing wax, sealant or coating
- Sun safe
- Stated safe to use in sunlight
- Dilution ratio
- Not published
- Foam cannon dose
- Not published
What it does well
- pH neutral, stated plainly, with an explicit claim that it does not remove existing protection
- Adam's states it can be used in direct sunlight, which most soaps quietly cannot
- Gallon pricing brings it to roughly $0.31 an ounce
- Concentrated, so a capful in a bucket is the intended dose
Who it is not for
- No dilution ratio published, so the concentration claim cannot be checked
- No pH figure published, only the word neutral
- The 16oz bottle is poor value against the gallon
How this score was calculated
- Protection claimdropped
- Nothing in this category is bought on how long it lasts, so the axis is dropped and the other weights are re-normalized.
- Capabilitydropped
- Adam's Polishes does not publish a figure for published dilution on this product, so the axis is dropped and the remaining weights are re-normalized.
- Cost per ounce10.0/10, weight 16%
- $39.99 for 128 oz works out at $0.31 an ounce, scored against a band of $0.35 (good) to $1.60 (expensive) for a wash soap.
- Price against the ceiling1.1/10, weight 14%
- A listed $39.99 against the $45 one upgrade in this category realistically tops out at. A list price captured on the compile date, not a live price and not what you will pay.
- Written commitmentdropped
- Adam's Polishes publishes no warranty term on this product's own page, so the axis is dropped. On a tool that is worth noticing, and it costs the product points on transparency instead.
- Spec transparency6.7/10, weight 18%
- 4 of the 6 specifications we went looking for are published by Adam's Polishes. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $39.99 per Adam's Polishes' own store, gallon, captured on the compile date below. Not a live price and not what you will pay — the button is where the real number is.
Specifications from Adam's Car Shampoo gallon listing, compiled September 8, 2026.
No live price is currently verified, so every button here reads Check price rather than a number we cannot stand behind. Why we do it that way.
Questions people actually ask
+Is P&S Pearl safe on a ceramic coating?
+Is Adam's Car Shampoo pH neutral?
+Can I use either in a foam cannon?
Where these figures came from
- The Rag Company's P&S Pearl listing — retrieved 2026-09-08
- Adam's Car Shampoo gallon listing — retrieved 2026-09-08
Every figure on this page is a published manufacturer or authorized-retailer claim, not a measurement we made. How we research explains exactly what we did and did not do.