Quick answer
Caterpillar EC-1: EC-1 is the Caterpillar specification for extended life coolant (ELC) in Caterpillar engines.. 3 products in our directory list it. Buy one that names the exact code from your manual.
Key takeaways
- 3 coolants in our data list this code.
- Match the exact code and suffix in your manual, not the colour.
- A listed code is the coolant maker's claim.
Confirm the specification in your owner’s manual before buying. Product examples are not a fitment guarantee.
On this page
What the code means
EC-1 is the Caterpillar specification for extended life coolant (ELC) in Caterpillar engines.
In our directory, 3 products from 2 brands (Recochem, Zerex) list this code. Chemistries their makers state: HOAT (1), OAT (1). Forms: Concentrate and Premix 50/50 (2), Concentrate (1).
For the make-by-make answer, see the heavy-duty diesel coolant guide.
Coolants whose maker lists it (3)
Each row is a product whose manufacturer lists this code on its own page or datasheet (data checked 22 Oct 2026). A listed code is the maker's claim; we have not tested the products. Products with a checked Amazon listing come first.
As an Amazon Associate I earn from qualifying purchases. Commissions never change which products we list or what the data says.
How to use this list
- Find the exact code in your owner's manual, service book or equipment documentation.
- Pick a product above that lists the same code, including any letter or suffix.
- Open the product page to read the maker's exact wording ("approved", "meets" or "suitable for" are not the same).
- Do not mix chemistries. Check with the mixing checker before topping up.
Related spec codes
Cummins CES 14603 and CES 14439 · Detroit Diesel 7SE298 · TMC RP-329, RP-302, RP-338 and RP-364 · MAN 324 (Typ SNF, Si-OAT, NF) · MTU MTL 5048 · Deutz DQC CA-14, CB-14 and CC-14 · All coolant specs
Buying for a fleet?
Need drums, totes or bulk delivery of a coolant to this spec? Tell us the spec, volume and region and we pass the request to relevant suppliers.
Request bulk coolant quotes →Frequently asked questions
Which coolants meet CAT EC-1?
In our directory, 3 products list it, including Zerex G05 Antifreeze Coolant, HD EXPERT PREMIUM Antifreeze/Coolant, HD Expert EXTREME Antifreeze/Coolant. The full list is on this page.
Can I use a universal coolant instead of CAT EC-1?
Only if the maker of that universal coolant lists this exact code on the label or datasheet. "Compatible with all makes" is not the same as listing the code.
Where do I find the CAT EC-1 requirement?
In the owner's manual or service literature, usually in the fluids or capacities section, and sometimes on the reservoir cap.
How we source this page
- Facts come from manufacturer pages, datasheets, owner's manuals and standards bodies, linked under Sources.
- We do not test products, and no brand pays to be listed or ranked. Advertising and affiliate links are labelled and never change the data.
- Anything we could not find is marked "not published" rather than guessed. Spotted an error? Tell us.