Thanks for the underline, it's a nice alternative to shouting or using bold.

Despite these visual aids, I don't quite follow what your post adds in trying to unravel the misconceptions and myths regarding oil certifications or viscosities. 'Better' is a relative and subjective term. Making nebulous references to 'people' who, for vague reasons, like the old product 'better' leads nowhere.

Are you implying that older formulations of oil had even higher concentrations of zinc/phosphorus and that this was superior? Do you have the hard numbers of before/after?

BTW- let's cut the hostility and condescension before this, like many other oil posts, get locked.

 

I have been running regular Pennzoil 20w50 (part# 3569) in my 97 XJ6 for the last 4 years. I change the oil every 3,000 miles and the car has over 100,000 miles now, no engine noise, smooth and strong.

Keep your oil clean and up, the 4.0 has a tendency to leak a bit of oil from the front of the head. I find the more viscous oil, the less leaks.

Since you are not in a sub zero climate, 20W50 should be fine. One spring when I drove across the Rockies and up north I switched to 15W40.

My engine sounds quieter with the heavier oil and does not drip nearly as much oil since I am back to 20W50.

 

Find today 10w40 penzoil with API SH, somebody use these oil?

 

Sounds perfect to me.

 

I'd also stay with at least a 40 weight oil (the AJ16 non supercharged 'allows' 0W-30 oils (synthetic only) and 10W-30 oils are only when ambient temperatures are less than 60o F, but 40 weight is preferred. The AJ16S supercharged does not 'allow' any 30 weight oils - there is a Jaguar TSB regarding this attached in an earlier post in this thread). (Note: a lot of this is due to 1990's oil technology, when the base stocks and visosity index improvers weren't as good as today - these days a 5W-30 oil will be as 'sturdy' as a 10W-30 oil in almost all categories - except maybe NOACK volatility)

I'd use the following (apart from some boutique oils, these are the best oils you can get) - but then I have a relatively rare XJR6 which has a very high torque (378 lbs ft/512 NM) output, putting a lot of load on the main and rod bearings.

Some of these are primarily marketed for Diesel engines (top three), but they are dual rated for gasoline engines as well - these three are among the top synthetic oils, but are typically priced at 2/3rd of the synthetic oils primarily marketed for gasoline car usage. And these dual rated gasoline/diesel oils will outperform a large number of 'consumer grade' synthetic oils. The other oils in the list are top of the line synthetics with European manufacturers approvals.

Mobil Delvac 1 5W-40 / Mobil TDT 5W-40
Shell Rotella T6 5W-40
Chevron Delo LE Synthetic 5W-40
Mobil 1 0W-40
Pennzoil Ultra 5W-40
QuakerState Ultimate 5W-40
QuakerState Ultimate 5W-50
Castrol Syntec/Edge 5W-40
Castrol Syntec 0W-30 (only 30 weight in my list, and only for the XJ6 - not for the XJR6 or XJ12)

Motul also has some very good oils.

The 10W-30 synthetic blend is ok for right now - no need to worry about it. It most likely has reduced ZDDP (Zincdiathyldithiophosphate) as others mentioned above - since the cams/valve buckets are well worn in by now, it should not cause any damage. However, I'd probably run it with the 10W-30 for less than 4000 miles and then switch to one of the oils above. For filters, I'd use Mann/Mahle/Wix/Napa Gold.

 

I'm thinking of changing from 10w40 to 20w50 on my next change. I've seen it recommended here and my Jag Tech has also recommended it.

 

Being a warm climate like Southern Cali, it would not hurt. I ran Mobile 1 0W-40 in my 97 XJ6. The perfect weight for the Chicago climate. Thin cold viscosity for the dead of winter starts yet still a 40 weight at operating temps for the summer time. Yes if I lived in Florida or Cali I would gone to a 50 weight.

 

The air cooled Porsche crowd likes Brad Penn, the old Kendall. It has the ZDP for the cams. They use 20w 50w.

Penn does make all the weights.
Welcome!

 

Here in Japan we often use 10W-40 or 20W-50. We also have severe climate like 100F in summer and 25F in winter... Anyways, I once used 10W-30 in summer but I think it was too thin for an AJ16. Mine cost a lot of oil and I had to add 1 liter of oil at every 5000km.
The AJ16 is actually an old engine, at least its block is the same as AJ6, which was introduced in 1986(it was not even the latest spec at that time), so I think it needs a kind of oil for older models.

 

after reading all this and looking at the Jaguar updated oil chart for AJ16 engine I bought Castrol Edge 10W30, titanium technology. I do not know if anyone tried it. It's full synth oil. Bought also a WIX filter.
Any hints or comments on my choice ?

 

Should be ok, Wix is as good as any and better than some. Keep an eye on the oil level and if it drops then it might be worth going back to 20W50 at the next oil change.
Can I ask if you have a ‘40 or a X300? I notice that you reference the AJ16 engine?
Just be careful when tightening the sump plug that you don’t over torque it, plenty of anecdotal evidence of them stripping (BTDT)

 

I run Edge 10W-30 in my XJR, and Magnatec (15W-40 I think) in my 3.2 Daimler 6


My only comment would be, watch the oil pressure light and listen for rumbling crank/big-end bearings on cold startup.
I once had a Fram filter on my X300 which seemingly had no non-return valve, so every morning the oil pump had to fill all the oil channels before pressure came up. This is avoided with good filters - I stick to the genuine Jag one for the sake of a few more $$

 

Hello I Returned the Castrol Edge 10W30 and I got the Mobil 1 10W40.
My car is 96 XJ6 X300
the problem is that this engine never had full synth oil.
But anyway Jaguar recommends full synth and this time I wanted to try it.
Hope it's not a bad choice. According to the Jaguar technical bulletin paper on this thread 10W40 should be fine. I live in California.

 

Your engine was not designed specifically to require synthetic oils. It's use will be of no benefit.

 

Hmmm. I don't remember that from my X300/XJR days.

FWIW, I used conventional oil, whatever name brand was on sale that day, and changed at 5000-6000 mile intervals. At 171000 miles when I sold it she was still purrin' like a tomcat in a dairy

Nothing bad will happen, if that's what you mean.

Tangible, real world benefit? That's another question. I suspect you'll benefit from it more than your engine will...and there's nothing wrong with that

Cheers
DD

 

I use Castrol Edge 0w40 full synthetic. At $26/5 quart jug, it’s really not much more expensive than a conventional oil. I leave it in there for about 7,500 miles and get it out.

The synthetic makes me feel better about leaving the oil in there longer. With a conventional, I’d be changing every 3,000.

These are my preferences, and at $60 a change with the filter, twice a year, I’m happy,

Could I go with conventional and spend $50 a change, twice a year, I suppose...

 

I have a 1997 XJ6L (X330) it has the AJ16 engine with 182,000 miles on the odometer. It runs well, but I'm afraid to put too light (5w or 0w) of synthetic oil in it. It is currently using synthetic oil, so I want to stick with it. If I can find it, I would consider a 5w-40w synthetic oil. I plan on driving to Baja California Norte and want the protection of heavier weight oil during the "heat of the day" as I travel south.

Thoughts? Opinions?

 

You will find that a heavier oil will work better in the heat. I once had a 'regular oil change where they put in 5w 30 fully synthetic oil and it didn't take long before the engine rattle showed.
I ended up putting some Lucas Oil Stabilizer to increase the viscosity and that was enough to settle things back to normal again.
If you are going to be in Baja, I would suggest going for 10w 40 or 10w 30 at least.
I haven't seen any issues using fully synthetic, but some will recommend a traditional oil.
From my experience in California, I would go with 10w 40 so you keep that higher temperature viscosity.

 

I am spending but a week (only driving down and back to the tune of 2310 miles). The rest of the time, I'll be spending in the Pacific Northwest. (Northwestern Oregon to be precise). Is it still advisable to go with 10w-40w?

 

The attached pdf has the oil recommendations depending on average weather temperatures
If it's only a short term stay then you might be ok. Maybe pick up a bottle of Lucas Oil Stabilizer just in case you get rattles while you're down there. It definitely resolved the issue on my N/A 4.0 in central California.
I suspect that 5w 30 oil may well show rattle signs in the heat down there.

These are the suggested viscosities/temps for normally aspirated engines,

Hope this helps.