Antifreeze every 2 years??

[William2]

The recommendation is to change the antifreeze every 2 years. Is the reason for this that the mixture looses it's anti corrosive protection after that period of time and is the 2 year period less necessary with the average use a classic car gets?

[RichardHawkins]

William,

I think you are correct, in that it is the corrosion inhibitor that is consumed. I have a friend, retired like me, who used to work in the oil industry, and if I remember correctly that's where the advice came from. I think Millers Oils sell the corrosion inhibitor separately.

Richard Hawkins

[AHM]

Yes, it is because the inhibitor gets used up.
No, it has the same surface area to inhibit whether you drive it or not.

[ricarbo]

I understand it's important to choose the right antifreeze. There is a big range to choose from. If your car is standard it has a cast iron block, aluminium head, a heater made of I know not what and a radiator made with copper, brass and with lead soldered joints. Modern radiators are usually aluminium, so modern antifreeze is the wrong thing, being incompatible with the lead soldered joints, or so I've read.
regards
Richard

[rgh0]

In Australia i use red OAT type long life Nulon coolant in my modern cars with Aluminium radiators as this is the type of coolant they originally came with.

http://www.nulon.com.au/products/coolin ... ed_coolant

I use Nulon green long life coolant in my Lotus with copper and solder radiators which are not protected by the Red OAT type coolants - This has 4 year life versus 8 years for the red. Most "normal" green ( maybe blue in some markets) has a recommended life of 2 years before the corrosion inhibitors are depleted.

http://www.nulon.com.au/products/Coolin ... ix_-_Green

If you explore the Nulon web site you will see a range of other options up to a all singing all dancing 10 year life version !

cheers
Rohan