I'm just compiling a list of the oils and fluids needed to refill our 900t when the engine and gearbox etc. goes back in (and for general servicing in the future).

The Haynes manual states the following:

Engine Oil: Castrol GTX
Transmission: Castrol Hypoy B Gear Oil
Wheel bearings: Castrol LM Grease
Brake fluid: Castrol Girling SAE J1703c

Obviously technology has moved on and modern fluids are better (maybe). However, I'm very aware that you can't just 'fill her up' with the first thing that you pick up of the shelf. In the case of brake fluid this could lead to disastrous consequences.

Searching online is more confusing than helpful.

What does everyone else use?

Thanks in advance.

There's an almost continuous oil debate on the Fiat 500 forum, largely propelled by me.[emoji3] Lots of people swear by Halfords Classic 20W50 engine oil, others go for high-end synthetics with wider ranges of viscosity, eg. 10W60. Recently I've just let the online selector choose my oil and all is good. The big unknown is whether the lack of old-fashioned additives which are nowadays missing from oils will cause camshaft wear. In view if that worry I'm trying out Mobil 4T motorcycle oil which has the additives and is 15W50.
Gearbox oil is a nightmare with lots of contradictory specs and claims....some people use engine oil! If your brakes have been fully drained and overhauled then there's no problem; just use any DOT4.
I use cheap grease from Toolstation.
I'll let you know when I drain and fill my wagon which may be quite soon.

On the off-chance I dropped an email to Castrol... and got a reply

Here's the response from one of their techies.

Engine Oil: Castrol GTX –> GTX 15W-40 or GTX 10W-40 or better still … Magnatec 10W-40 if the engine is in good order

Transmission: Castrol Hypoy B Gear Oil –> Manual EPX 80W-90 or Universal 75W-90 ( better part synthetic )

Wheel bearings: Castrol LM Grease –> Spheerol EPL 2 ( only in cartridges ) or any lithium multipurpose grease

Brake fluid: Castrol Girling SAE J1703c –> any DOT 4 brake fluid

Probably confirms what most people already knew but nice to know from one of the 'experts'.