Engine and diff oil recommendations for 4.0 XJ40

[mccrackenj]

Me again, monopolising this forum!

What are everyone's opinions for suitable oils for my 1990 4.0 Daimler, with 46k?

I want to change engine and diff oils asap and I'm interested in recommendations. The car will probably do only about 2k per year of gentle pottering, the engine oil will be replaced every 12 months maximum, but I don't intend to replace diff oil again for at least 5 years, if I have the car that long.

[Jaguar steve]

I've used the Morris lubricants range in the XJ, the other family cars and my daily shitter for years. Although they are not the cheapest they're well specified and have a following with Bikers, which is usually a good thing.

GSF have very reasonable prices on Fusch lube oil, including Supersyn at the moment so if cost is an issue check them out

I always use a full synthetic - and change it more often than Jaguar recommend - it cost more but IMO the benefits far outweigh the cost. It's a subjective thing but I think all the XJ's I've owned have run really well on synthetic oil even at high mileages.

Years ago changing my old Series 3 XJ from Castrol GTX 15/50 to a synthetic 10/60 gave a noticable improvement in fuel consumption that more than paid for the extra cost of the oil.

[GavinPearson]

I'd use 10W40 fully synthetic for the engine, and SAE90EP fully synthetic for the diff.

I would also have the transmission fluid changed, change the antifreeze too.

Do this and the car will last, at least mechanically.