MidShire CoolGuard OAT

Product Overview

MidShire CoolGuard OAT is an Organic Acid Technology (OAT) coolant concentrate designed for use in modern petrol and diesel engines. The OAT inhibitor system provides long-life corrosion protection for aluminium, cast iron, copper, brass, and other metals commonly found in automotive cooling systems.

Unlike conventional silicate-based coolants, OAT technology provides extended service life — up to 5 years or 250,000 km under normal operating conditions. It meets BS 6580 and ASTM D3306 requirements and is suitable for use in a wide range of modern passenger cars and light commercial vehicles.

Important: Do not mix OAT coolant with other coolant types (conventional silicate or HOAT). Always drain and flush the cooling system before switching coolant technology. If unsure, contact our technical team.

Typical Applications

Modern petrol and diesel passenger car engines
Light commercial vehicles with aluminium-heavy cooling systems
Turbocharged engines with extended coolant service requirements
Fleets operating extended coolant change intervals
Vehicles where the OEM specifies an OAT or G12+ type coolant

Key Features & Benefits

OAT inhibitor system — long-life corrosion protection without silicates
Up to 5 years / 250,000 km service life under normal conditions
Excellent aluminium protection — suitable for modern aluminium-heavy engines
Compatible with cast iron, copper, brass, and solder alloys
Good freeze and boil-over protection across a wide dilution range
Does not require silicate top-up additives during service life
Meets BS 6580, ASTM D3306, and G12+ equivalent requirements

Technical Data

Product Name	MidShire CoolGuard OAT
Product Type	OAT Coolant Concentrate
Inhibitor Technology	Organic Acid Technology (OAT)
Colour	Blue-green (may vary — confirm on TDS)
Freeze Protection at 33% vol.	approx. −20°C
Freeze Protection at 50% vol.	approx. −37°C
Boiling Point at 50% vol.	approx. 108°C (unpressurised)
pH (concentrate)	7.5–8.5
Service Life	Up to 5 years / 250,000 km

Dilution Guide

33% concentrate / 67% water — freeze protection to approx. −20°C (summer/mild climates)
50% concentrate / 50% water — freeze protection to approx. −37°C (standard UK recommendation)
Do not use undiluted — always mix with clean water before use
Recommended water: deionised, demineralised, or low-hardness mains water