Oil choice for specific manufacturers

[Loose_Cannon]

I've bought another car (2007 Jag XJR) and was overjoyed to see it takes 5W-30 as I've got gallons of decent synthetic from a recent previous vehicle gathering dust on the shelf.

However when I get a look the dusty/shelfy stuff its says its for Porsche/VW on the side, and a website says there is a different formulation of this same oil for the Jag (Ford).

Is it really important with frequent (3-5000) changes that I prefer? There is obviously generic 5W-30 available anywhere with no specific vehicle in mind which could just as easily end up being used by an owner.

My inner skinflint says toss it in and change frequently but am I really risking anything by doing so?

Edited by Loose_Cannon on Thursday 30th November 11:04

Edited by Loose_Cannon on Thursday 30th November 11:07

[Loose_Cannon]

Thanks all, sorry for late reply PC on the blink.

Its just taking up space so I'll just consider it a flushing exercise until I can get some Millers in.