








⚡ Unlock your engine’s hidden potential — clean, quiet, and powerful!
The 505 CRO Oil System Treatment is a 12 oz engine additive designed to clean sludge, improve lubrication, reduce emissions, and restore performance in high-mileage gas and diesel engines. Trusted by professionals and rated 4.7 stars, it seamlessly integrates into oil changes to keep your engine running smoother, quieter, and longer.





| ASIN | B0CYXTJ8P6 |
| Best Sellers Rank | 389,487 in Automotive ( See Top 100 in Automotive ) 283 in Engine Oil Additives |
| Brand | ATS CHEMICAL |
| Customer Reviews | 4.7 4.7 out of 5 stars (270) |
| Date First Available | 10 Dec. 2024 |
| Item Weight | 318 g |
| Item model number | DSI1040 |
| Manufacturer | ATS Chemical |
| Manufacturer part number | 1040 |
| Model | 505CRO |
| Product Dimensions | 15.24 x 5.59 x 5.59 cm; 317.51 g |
O**O
It improves the engine life, and clean all residue of sticky oil and dirt.
B**.
I have a 2016 Jeep Cherokee with 330,000 miles. After amazing results using ATF Chemical 505 CRF Fuel System Treatment (see separate review), I ordered this ATF Chemical 505 CRO Oil System Treatment. I believe my results are of particular interest because I did not perform the treatment by adding the product to dirty old oil, as you would right before an oil change, but I added the product to fresh clean oil right after an oil and filter change. Wait till you see what happened. The instructions say to add the product to your engine's oil, run the engine at "high idle" (some mechanics say @ 2,000 RPM) for 10 minutes or more, then drain the treated oil, remove the oil filter and install a new filter and new oil. However, what I did was last night I added the product to the fresh oil that was in my car, ran the engine at regular idle speed (say 750 RPM) for 10 minutes, turned off the engine and let it sit overnight. This morning I started the engine and moderately drove the car (2,000 RPM max) for 40 minutes, parked the car and let it sit for a few hours, then drained the oil. I was very curious to see what the oil looked like when I drained it. Would it look like the brand new oil that I had just put in the car? The answer is an emphatic NO - the oil was PITCH BLACK - it looked like old oil coming from an engine that was overdue for an oil change. In my opinion this stuff does what it was designed to do. It cleaned out the built-up carbon deposits internal of my engine. After installing a new filter and new oil I drove the car today as normal for about 90 minutes around town and highway. It is probably too soon to tell but I think the engine runs smoother and quieter. I will now be using these products on all my vehicles (5 cars/trucks, 4 motorcycles) and recommending this product to everyone. I am SO glad I found out about these products from a mechanic on YouTube who says these are "products your mechanic does not want you to know about" and that they will "make your vehicle last 3x longer". I have no doubt this is so. Easy to use. Does as advertised. Worth every penny.
J**K
Good product
D**.
I haven’t used it yet, but the product comes with very high recommendations
A**R
It does 100 percent as it says it will, few products do.
Trustpilot
2 days ago
2 weeks ago