As do all owners. Owners can even choose to exceed spec.

 

I'm sort of conflicted about that.

I like to view blackstone results so long as someone else pays for it

Was there an explanation for the lead content?

In Arlington, 15W40 would do you fine. And Shell Rotella has got to be one of the
best and cheapest in that category. Yes, it *is* API rated for spark engines.

You might like Shell Rotella T6 0W40 full synthetic out to 6000 miles, although
5000 miles is a lot easier to track on the odometer.

Both of the above have better HTHS numbers than even guaranteed by
ACEA A3/B4 which stipulates a minimum of 3.5

 

I just did my first oil change in this car. Used regular (non synthetic) 10-40. Will change again in 3000 miles.

 

I did the oil change yesterday with Maxlife 10W40 and am happy with the results. The V12 was very smooth, quiet and responded well on the 30 mile drive after the change. Cost was $17 per 5 quart container and I needed two of them. The temp gauge actually was slightly lower during the drive then when I was using Mobil 1 0W40. Running a little cooler is always good for our V12's. LOL...

 

I hope you're not attributing any of this to the oil change........

 

I have owned dozens of vehicles, including many collector cars, to know when I feel or hear a difference, good or bad... Most likely, it was just from having fresh oil and a slightly cooler outside temps that made the car perform great. I really do believe Maxlife 10W40 is a good match for the XJS V12.

 

I have an update.

I changed the oil out, at 4,055 miles. The report came back better than the last one.

Conclusion?: If you're using Mobil1 0w40, it seems to make sense to change the oil every 4,000 miles.

I've since switched to Castrol Edge 0w40. Not sure I'll be running another one of these tests though. I think I got what I came for.

 

If you're going to change oil at 4K miles interval, don't bother with synthetics and don't bother with sample analysis.

 

Yes, it would certainly seem to be the case. The premium cost for some synthetics are now minimal. I managed to order two 5 quart jugs of Castrol Edge 0w40 for just a few cents over $20 each. Even conventional oil does not get much lower than that!

I do think I'm done with the sample game though. I may run one more now that I have switched to Castrol Edge, to see if there's any difference.

 

i think you are accually missing somthing.

universal averages are based on 4000k miles. so there for you run your oil longer you will show higher wear metals because it has been in the engine longer. the tbn is still strong so no need to change early.

the 4k mile check was just to make sure that you fall in the averages at that millage. you can continue to change at 7500 and use your first sample as your averages. if it really worries you consider a 4k mile oil filter change without draining your oil.

 

Thank you for putting that into perspective! Makes sense.