Time to do an oil change. Last Jag was a 4.0 S Type, 250,000 km. Used Mobil 1 5-30. Just looked up last change on the XK8 and it was Mobil Delvac 15/40. Which one?

 

Mobil 1 0-40 FS is going to be the best oil you can find that meets the manufacturers specifications and is readily available at a reasonable price. Walmart and Amazon usually have it for $28 per 5 quart jug.

its been working very well for
me in numerous vehicles over at least 15-20 years. No leaks, no measurable wear

Z

PS that said, changing the oil and oil filter often matters the most, not the type of oil.

 

0W oil is only a recommended specification for winter ambient temperatures below -20C / -5F. If that applies to the OP, then fine.

Richard

 

not according to the chart in my owners manua. It shows the 0w-40 that I mentioned perfectly appropriate for temperatures from 50 F to 90 F.

perhaps you are thinking about the 0w-30 which is at the lowest end of the ambient air temp scale.

 

That's interesting. It's not the oil recommendation chart for the early XK8's, which I'm quoting from, which shows each oil grade as a separate horizontal band above the temperature scale and is quite clear that the only oils which are 0W rated at the winter end are for use where the temperature is below -20C.

From your chart, it appears all those 4 oil grades are deemed suitable for -30C to +50C. That is certainly not the Jaguar recommendation for the pre-2000 XK8s, although I would not imagine that it would do any harm.

Richard

 

FWIW, the manual for my car is for the 2002 YOM 4.0 L.

 

Technically Jaguar is fudging with that scale. They are saying that all of those oils are acceptable for the full range of possible operating temperatures, and the user should lean towards whichever most closely hovers over the predominating temperature below it. There is no way that a modern 0W-40 of even the time when the car was new cuts off at 90 deg F. It is great in the hottest of deserts where i have driven the car. One thing which i will admit is that with the exact same brand and oil type varying only by 0W to 5W, the car does not consume oil with the 5W and will use 1/2 quart over 3K with the 0W-40. Probably something with the volatility of the product, go figure.