Anti freeze question

[clubsport]

I need to slightly top up the coolant in my car(sorry water cooled) I understand that the mix is 50/50 antifreeze/water.however the manual states it has to be Porsche approved etc....I don't want to revoke the warranty,is it ok to go into a garage or halfords and buy something that is BSc approved or have I got to go & buy the overpriced real stuff from my main dealer?

[domster]

Some engines do require special anti-freeze - I believe the K-series Rover engine is one - as they have an alloy head/block and use a thin rubber seal on the head gasket waterways. Apparently the wrong kind can corrode the head gasket or eat the alloy or something daft.

However, not sure what the case is with your car. I am 90% sure it wouldn't make any sodding difference

[argonaut]

If you only need half a litre or so, you may as well top up with plain water. This won't affect the antifreeze properties significantly and saves trying to get hold of the Porsche stuff.

Don't use a different antifreeze.

I bunged half a litre of Evian in my coolant system a few weeks ago - only the best for my 996!

[clubsport]

Thanks for the response i have the difference between max / min on the 996 to top up...i will have to find a suitable mineral water.
Should be fairly cheap,it costs me a fortune with my morgan as it only tales malvern hills still mineral water,,cheers