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Smallblock454 · 02-16-2017, 09:13 AM

I'll get it from BASF. See post #16 from Deserion.

It's G30 (OAT) for the 986. Why? Because it's an alloy engine. And because it has a very long change interval (very good long term stability) compared to other fluids.

In general it seems you can also use G40 (Si-OAT). But you have to flush the system completely.

Don't mix silicat free coolant fluid like G30 with silicat containing coolant fluid like G40.

I don't know how the parts in the 986 cooling system react on the silicat. Don't know if Si-OAT is 100% compatible with the 986 coolant system on a long term.

In general silicat reacts with alloy and generates a protective layer. But this layer doesn't last very long. So they developed the OAT coolant fluid. The long term alloy corrosion protection is much better.

This is why i would recommend to use BASF G30 for a 986 car.

The bottle jakeru shows is the newer G40 stuff.

Regards, Markus

02-16-2017, 09:13 AM	#19
Smallblock454 Registered User Join Date: Jun 2014 Location: LB, Germany Posts: 1,515	I'll get it from BASF. See post #16 from Deserion. It's G30 (OAT) for the 986. Why? Because it's an alloy engine. And because it has a very long change interval (very good long term stability) compared to other fluids. In general it seems you can also use G40 (Si-OAT). But you have to flush the system completely. Don't mix silicat free coolant fluid like G30 with silicat containing coolant fluid like G40. I don't know how the parts in the 986 cooling system react on the silicat. Don't know if Si-OAT is 100% compatible with the 986 coolant system on a long term. In general silicat reacts with alloy and generates a protective layer. But this layer doesn't last very long. So they developed the OAT coolant fluid. The long term alloy corrosion protection is much better. This is why i would recommend to use BASF G30 for a 986 car. The bottle jakeru shows is the newer G40 stuff. Regards, Markus Last edited by Smallblock454; 02-16-2017 at 09:47 AM.