Going to do a maintenance (at least an oil change and check of everything) when I get my car (which unfortunately has been delayed till tuesday). What oil do you guys use in your cars? For reference, it's the 4.0 litre 6 from 1994. What's the recommended weight?

 

I am using Mobil 1 0w30 because it was on sale. It's a pretty thin oil.

Next time, I might use 15w40 Shell Rotella diesel oil. I used in on my Mercedes and it ran very well. The reason I use diesel motor oil is because it has more zinc and cleaning chemical. Some Mercedes owners like to use it in old Merc.

 

Personally I run synthetic, that's a whole other conversation in it by itself. I run Mobil1 15w-50 in the warm months and Mobil1 0w-40 in the cold. I change my oil and filter twice a year. Stay away from Fram filters.

I suppose I would run Castrol Syntec's 5w50, but its not as easy to find.

Here's what Jag recommends:

 

I use Castrol Syntec 20W-50 in the V12's. Says it is for Classic Cars. Good idle pressure - Stays clean. Not to expensive. Change filter with every oil change.

XJSPaul

 

XJSPaul,

That Castrol Syntec bottle specifically says that it is NOT formuated to comply with catalytic converter requirements and may damage your cat.

The OP is driving a '94, so I don't really consider that AJ6 engine as a classic engine. I'd recommend staying away from the "classic car" oil for the newer, facelift cars, however I don't know enough about the V12s, old or new to include your engine in that statement.

 

im running mobil 1 0w-40 it could be 10-40 but i cant remember. It seems pretty good so far. Its fairley thin cold, but before fixed my banjo leak i only lost like a half quart in a couple of months.
im probably gonna put 15-50 in it next time because its usually pretty hot here.

btw dont buy oil at a parts store, its almost twice as much. I got 2 jugs of mobil1 which is enough to change oil for $50 at walmart. At advance or similar it would be $60-70.

see what is says in your manual. If its generally hot where u are run something a bit thicker.

btw i idle at like 65ish

 

Question I'll get the answer to when I get my service cd's but I'm impatient while I wait to pick up my car tomorrow (crosses fingers and toes)...

It takes 8 quarts correct?

 

As long as the oil meets the API service rating for the car in question, then it is safe. A AJ6 engine will have a factory API service rating of SJ or before. Certainly not SM.

The API SM/CJ-4 specification was introduced in recent years. As differentiated from previous ratings such as SL, it addresses two main concerns: manufacturer concern that they be able to meet the EPA mandated 120K mile catalytic converter warranty and the newer catalytic converter internal designs which are more prone to clogging. The main effect is a substantial reduction in ZDDP which is a anti-wear additive.

When specifying factory fill, the manufacturer has multiple constraints to consider. Some of them are not directly related, or completely unrelated, to engine longevity. Their goal stops at the end of the warranty period. After that, the owner is on his own.

It is cheaper to replace a failed catalytic converter than a failed engine.

 

Another oil to consider is the Castrol 15W40 Diesel. It carries a API SI rating when used in gasoline engines.

 

I was told that the "Catalytic Converter" / ZDDP problem was a 2000 and newer item. My "NEW" Jag is a '95. However, I will try to reconfirm this.

XJSPaul

 

Castrol claims that the catalytic problem is from 1993 and up, I believe.

Mobil1 15w50 has 1,300ppm zinc and the 0w40 is a bit less at 1,100ppm.
http://www.mobiloil.com/USA-English/...duct_Guide.pdf

I hate to use another forum as a reference but it's all I could find, but it is from the world of BobistheOilGuy. They reference that (1) Castrol's classic 20w-50 is not beneficial for flat tappet engines and (2) although they won't disclose the actual ppm of zinc, they'll guarantee a minimum of 1,200.

Castrol Syntec 20w50 for classic cars? - Bob Is The Oil Guy

I find that fact (1) to be more interesting.

 

Yea, a quick look at ZDDP. Oil, Catalytic Converter on Google gives many items to read, most pushed by ZDDP corp. However, I found that starting in the late '90s the EPA's program called for 100,000-mile catalytic converter life by 2004, 120,000 miles by 2007, and 150,000 miles by 2009. That is when the ZDDP started coming out of the oil. Additionally, in 2006, a new motor oil warranty category for gasoline engines was released designated GF-4.

So it appears that our 80's, 90's XJS's are "Classic" cars that can run with the ZDDP.

Now if anyone can find other information, please post it.

XJSPaul

 

Logic dictates that if the car was manufactured before a specific API service rating was introduced, the car could not have required the features addressed by that API service rating.

The ZDDP reduction was in API SM. That standard was introduced November 30, 2004.

Thus, a manufacturer could not have possibly designed an engine to require API SM in a 1994 model year car. It would have to have been a SG or SH rating because those were the top grades available for service fill. A manufacturer would have great difficulty selling a car that calls for oil that will not be available for another ten years.

If SM can be avoided, SJ/SL would seem to be an excellent goal as far as engine longevity is concerned. The history of the Sx ratings is that each successive rating was an improvement in engine protection with SM being the first rating to ever be a retrograde step from the previous rating.

1200 ppm zinc is considered to be about the sweet spot for ZDDP in non-breakin usage.

 

Add about ten to twelve years to that.

 

Castrol, on it's website is sticking with 1993. It might have to do with additives other than ZDDP?

Castrol USA - Castrol SYNTEC 20w-50

Look under the "Key Benefits" paragraph.

 

Pretty sure the manual says to use 10w-30... But I will check it at lunch to make sure.. Of course I live in Mississippi so cold weather is not an issue.. and... it's 95 degrees down here right now.

 

Pick it up today (fingers crossed) and I'll check the manual. I will also go through the maintenance records. Talked with Dave at Redline oils and he recommended 10w30 at one year intervals. I'll probably go with shorter and a differenent oil till I know the car a little more. Thanks for al lthe input.

 

Here's what Jaguar Recommends for the AJ16

 

the manual doesn't recommend 1 oil. it recommends like 8 or something. There is a big diagram showing all the weights and there operating temps.

 

Don't have the manual but that's what I've seen online in various places. A lot of recommendations based on ambient temps. Oil has come a fair bit since these were built and generally there doesn't seem to be temp related recommendations anymore (especially to this degree).

One thing I saw on jag-lovers (on the XJ faq but recommended for our engines too) was 20W50 being the best. Seems like 0w40 is now the standard though.