Wash and Decontamination
Optimum No Rinse vs McKee's 37 N-914
The two rinseless washes that publish their dilution ratios, which is the specification the rest of this category quietly omits. They arrive at the same 1:256 and then diverge.
By Sawyer V. · Last verified 2026-09-27
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 | Optimum No Rinse Wash & Shine Optimum | The only wash chemical here that publishes its dilution | 5.3/10 | $27.98 - view on Amazon |
| 2 | McKee's 37 N-914 Rinseless Wash McKee's 37 | A pure cleaner that leaves nothing behind | 7.0/10 | $26.99 - view on Amazon |
Prices last verified September 27, 2026. They move constantly; the figure on Amazon when you click is the real one.
Side by side
| Optimum No Rinse | McKee's 37 N-914 | |
|---|---|---|
| Price | $24.30, kit with sponge | $24.99 for 32oz; $69.99 gallon |
| Rinseless dilution | 256:1 | 1:256, one ounce per two gallons |
| Waterless or clay lube | Not published | 1:128 |
| Paint prep dilution | Not published | 1:8 |
| Leaves behind | Not published | No film, per the retailer |
| Stated compatibility | All paint and coatings | Not published in those terms |
| Wash media included | ULTRA Safe Sponge | No |
| pH | Not published | Not published |
Both publish the ratio, which is rarer than it sounds
A rinseless wash is sold as a concentrate, so the dilution ratio is the price. Without it you cannot work out what a bottle costs per wash, and most makers in this category do not print one. These two do, and they agree: one ounce to two gallons, which is 256:1.
At that ratio the argument about bottle price mostly evaporates. A 32oz bottle of N-914 is 64 buckets at the published dilution. Whatever you pay for the bottle, the cost per wash lands in small change, and the real decision moves to what else the product does.
N-914 publishes three more dilutions
This is where they separate. McKee’s publish 1:128 for waterless washing and clay lubrication, and 1:8 as a paint prep before a coating. That is one bottle covering the maintenance wash, the dusty-car wipe-down, the clay step and the panel wipe before protection goes on.
Optimum publish the rinseless ratio and stop. They do state it is safe on all paint and coatings, which N-914 does not put in those words, so the compatibility claim runs the other way.
The film question
Obsessed Garage stock N-914 for a specific reason they put in writing: it only cleans, and leaves no film to change how your existing wax, sealant or coating beads. If you have just paid for a coating, a wash chemical that adds its own gloss layer makes it harder to tell what the coating is still doing.
Optimum do not publish a claim either way here. Their listing is about the wash itself and the sponge that comes with it, which is a fair thing to sell on: the method needs the right media more than it needs the right chemical. The rinseless roundup ranks the wider field.
Cold weather and version 2
McKee’s list N-914 as V2, stating more lubricity and easier drying in the cold. For anyone washing in a driveway in winter, easier drying is not a small claim: a rinseless wash in February is mostly a fight with a towel. The winter wash page covers the rest of it.
Neither maker publishes a pH figure, and neither publishes a coverage figure in square feet. Those blanks are printed in the tables above rather than filled in with an estimate.
Who should buy which
- You are starting from nothing: Optimum No Rinse, $24.30, because the kit includes the sponge.
- You want one bottle for wash, clay lube and paint prep: N-914, $24.99 for 32oz.
- You just had a coating applied: N-914, on its no-film claim.
- You want a stated all-paint-and-coatings compatibility claim: Optimum No Rinse.
- You wash outdoors in winter: N-914 V2, which states easier cold-weather drying.
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 only wash chemical here that publishes its dilution
Optimum No Rinse Wash & Shine
Optimum
Sold here in a kit at $24.30 with a sponge, and the listing publishes the number that matters: 256:1. One ounce makes two gallons. That single published ratio is why this product has outlasted every rinseless wash launched since.
- Dilution
- 256:1
- Stated compatibility
- All paint and coatings
- Kit contents
- No Rinse concentrate plus ULTRA Safe Sponge
- pH
- Not published
- Concentrate size
- Not published
What it does well
- 256:1 dilution published, the only stated dilution ratio anywhere in this hub
- Stated safe on all paint and coatings
- At 256:1, a bottle is a season of washes for anyone without a hose
- Kit includes the wash media, which is not optional with a rinseless method
Who it is not for
- Rinseless washing has a technique cost; done carelessly it marks paint faster than a hose does
- No pH figure published
- The kit price is for the bundle, not the concentrate alone
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.
- Published dilution5.2/10, weight 22%
- 256 parts water to one part concentrate, scored on a band running from 100 to 400. Published by Optimum.
- Cost per ouncedropped
- Either the list price or the container size is unpublished, so the division cannot be done and the axis is dropped.
- Price against the ceiling4.6/10, weight 14%
- A listed $24.30 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
- Optimum 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 transparency6.0/10, weight 18%
- 3 of the 5 specifications we went looking for are published by Optimum. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $24.30 per The Rag Company, kit with sponge, 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 Optimum No Rinse kit listing, compiled September 8, 2026.
2A pure cleaner that leaves nothing behind
McKee's 37 N-914 Rinseless Wash
McKee's 37
$24.99 for 32oz of a rinseless wash that Obsessed Garage chose because it only cleans, leaving no film to change how your wax, sealant or coating beads. The listing publishes its dilutions: 1:256 as a rinseless wash, 1:128 as a waterless wash or clay lube, and 1:8 as a pre-coating paint prep.
- Sizes
- 32 oz ($24.99), gallon ($69.99)
- Rinseless
- 1:256 (1 oz per 2 gallons)
- Waterless and clay lube
- 1:128
- Paint prep
- 1:8
- Leaves behind
- No film, per the retailer
- Version
- V2: more lubricity, easier cold-weather drying
What it does well
- Dilutions published for four jobs
- No film left to alter beading, per the retailer
- Version 2 adds lubricity and easier drying in the cold, stated
Who it is not for
- The retailer says to measure a capful, since caps vary
- No SiO2 or protection, by design
- Distilled or filtered water recommended, though not required
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.
- Published dilution5.2/10, weight 22%
- 256 parts water to one part concentrate, scored on a band running from 100 to 400. Published by McKee's 37.
- Cost per ounce8.1/10, weight 16%
- $24.99 for 32 oz works out at $0.78 an ounce, scored against a band of $0.50 (good) to $2.00 (expensive) for a rinseless wash.
- Price against the ceiling4.4/10, weight 14%
- A listed $24.99 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
- McKee's 37 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 transparency10.0/10, weight 18%
- 6 of the 6 specifications we went looking for are published by McKee's 37. Every blank row below is something the maker will not put in writing, and it costs the product points here.
List price $24.99 per Obsessed Garage, 32oz, 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 Obsessed Garage's McKee's 37 N-914 listing, compiled September 8, 2026.
Prices last verified September 27, 2026. They move constantly; the figure on Amazon when you click is the real one.
Questions people actually ask
+Is N-914 the same thing as Optimum No Rinse?
+Can either be used as a clay lubricant?
+Do I still need two buckets?
Where these figures came from
- The Rag Company's Optimum No Rinse kit listing — retrieved 2026-09-27
- Obsessed Garage's McKee's 37 N-914 listing — retrieved 2026-09-27
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.