I’ve just found 20l of Titan atf 4134 that I used on my Discovery 3 6speed auto can this be used in my 8speed or am I best selling it on and using something else 2012 Range Rover Westminster 4.4 TDV8
2006 Discovery 3 HSE 260k miles and still going strong with a new owner

If it’s approved for the ZF 8 speed box then use it. You will hear a lot say life guard 6 only but that’s a blinkered view and a very expensive option, as long as you use a top manufacturer which Titan are and it’s the correct grade (self approved) for your gear box then you are good to use. The “life guard 6” supporters will read from ZF’s documents that they only approve life guard 6, but they make the oil so they are only going to promote their own oil. The specifications of the oil are not secret and various car manufacturers will use their own approved make of oil as they have contracts with these companies... like Audi use Shell etc.

My opinion is don’t use the cheapest / unknown brands oils on market, they are probably ok but for peace of mind use a top brand like Chevron, Tipton, Mobil, Shell, Castrol, Motul etc are top brands and make suitable alternatives built to the required specs or even better spec’s.

5L of the correct oil costs less than a tank of fuel and only needs to be done every 50K miles.
Personally I wouldn’t risk ever using anything else to try and save a few quid.

Told you Furnitureman.... open a topic on oil will give you a few facts and a LOT of opinion.

It’s the same for vaccines, some will attribute something that happened just after they had the jab to the vaccine, these ‘effects’ have included hangovers and pregnancy. With auto box fluid changes on the internet there’s loads that have blamed a fluid change on a subsequent gearbox failure where the fact is the gear box was going to fail anyway. 🤦‍♂️

Just take peoples opinion with a grain of salt and do some research on facts and check your resource is legitimate. Big oil companies supply car manufactures the correct grade oil for ZF gearboxes, use as the end consumer just are not told this by ZF!