








⚡ Unlock your engine’s hidden potential — don’t let sludge slow you down!
ATS Chemical 505 CRO Oil System Treatment is a 12 oz engine additive designed to clean sludge, improve lubrication, reduce emissions, and restore smooth, quiet performance in high-mileage gas and diesel engines. Compatible with most vehicles, it enhances engine longevity and efficiency by targeting sticking components and restricted oil flow.





| ASIN | B0CYXTJ8P6 |
| Best Sellers Rank | #75,835 in Automotive ( See Top 100 in Automotive ) #303 in Oil & Fluid Additives |
| Brand | ATS Chemical |
| Customer Reviews | 4.6 4.6 out of 5 stars (294) |
| Date First Available | 30 March 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 |
A**R
It does 100 percent as it says it will, few products do.
P**L
It's worth the $55. I have a Toyota sedan that is 15 years new at 160,000 miles, as a maintenance action I treated the fuel tank with one bottle of 505 CRF Fuel treatment and while parked, ran the RPMs to 3,000 and held it there for 2 minutes to burn off carbon and clean the injectors. Within half a minute or so I could actually HEAR the car running to smoother. It reminded me of tuning an out of tune guitar string, the pitch/tone of the engine changed and the whole engine sounded smoother. 6 months later, the car still starts and runs like a dream. I can't promise you the same results, but I wanted to share my results with this product. As a sidenote...if you are reading this and have a car over 120,000 dont sleep on installing new spark plugs and install a new PCV valve. On some cars the install is relatively easy and the part is only $8 and now my car no longer burns oil! no more 1qt per month burned...
O**O
It improves the engine life, and clean all residue of sticky oil and dirt.
P**P
I’ve used this product in multiple vehicles over the years and it has performed well. This was the first time that I ordered it with the included funnel which worked great.
J**R
Treat your engine injectors to a good cleaning. Check out you tube to reset the engine control system for your vehicle. Otherwise, the cleaned injectors will use more fuel and the engine may idle roughly. Easy to do even if not a mechanic. Just follow the 3 or 4 steps in the correct order with the correct instructions made for your car or truck. Only needed once a year with some highway driving, 2 or 3 times a year in heavy city traffic.
Trustpilot
2 days ago
1 month ago