Hello all.
I’m working with a 1997 Jaguar XK8. That’s the 4.0. I’m curious, what specific oil would my car love the most because to me it looks like it’ll take anything. Washington summers are pretty hot but unbearable. Anywhere from 70-100 (21-37) and I push the car a decent amount. What would you folks recommend?

 

I had a funny click on mine sounded like a tappet but measurement showed it was not so I put it down to piston slap. Changed to 10W40 and its gone. For an older engine I think this slightly thicker oil will give better oil pressure and for your climate is fine

 

I don’t think you can go wrong with a 0w-40 or a 5w-40. A 5w-30 is a little light for your summers, IMHO.

However, the suggestion for a 10w-40 would be OK for your summers, albeit a little outside the factory recommendations. I’d be hesitant about using it for winter driving.

on the other hand, I’ve yet to go wrong by listening to a forum members experiences.

It would help with the piston slap noise as pointed out. Perhaps other could chime in, but in my experience the piston slap noise is just annoying, and does not require any special attention. In all the cases I’ve seen, and especially with my own 2002 XKR, the noise goes away as soon as the engine temperature gets above 140-160 F.

Here is the factory take on recommended viscosities. You can see it’s a sliding scale based on the ambient air temperature in your location.

In my locale I use Mobil 1 0w-40 exclusively, summer and winter (the XKR is my daily driver). Unless the oil change happens to come during the really brutal summers, in which case I go with 5w-40. Since I drive the car about 15,000 to 20,000 miles a year I go thru a lot of oil. What’s in the engine in the summer is very likely to be replaced by the time winter rolls around. Maybe not the norm.

 

Since I have just added a Range Rover to my fleet I have been watching Land Rover Time and the very educated German guy swears he will never have anything 30 in his cars so I think if its too cold for 10W40 then go 5 w40 . 10 W40 is specified for down to -10c by JLR. Not long ago we had 20w50 in everything and the winters were colder.

 

Although he's talking about a particular problem with crankshaft oiling on the Lion V6 diesel engine and refers to 5W-30 oil as 5W-Dumbass because it will facilitate crankshaft failure. It's not relevant to our petrol V8 engines.

Richard

 

Its on the JLR list and it stopped mine ticking so its relevant to my engine. Your car do what you like.

 

I most certainly will do ..... but unless my car is an X100 I won't talk about it in this forum. 😉

Richard