After all that reading on oil I'm almost afraid to ask…… I am about to chance my oil on the 07XK, and was thinking of going to a semi synthetic as opposed to Castrol 5-30. Any concern over semi synth? Car has 40K kilometres and I will probably put 12K on it this year.

 

One of the reasons that mfg's went to synt. oil was for it's extended life. I don't know what the OM says for oil change interval but if you change it in 5K miles I suspect it would be OK.

 

Didn't do any research on semi-synthetics but worst case call a dealer to see what they say. They shipped with synthetic so I would probably stay that route IMO.

Sorry if the information was a little unorganized but the main things I looked at were the Dr Haas documentation as I found it an interesting read and API standard chart which provided the information I was looking for.

Being I would be driving in temps that could reach 0 or below I wanted something with a low crank temp. Castrol was a bit high for my liking and will most likely stay with the Mobil 1. In warmer climates I would say the Castrol would work excellent but again, interval is more important.

 

Synthetic it is….. I do change the oil regularly but why tempt Karma.

 

Rotella is formulated and API rated for both spark and diesel engines.

 

I hate to add to the confusion on oil, but my 2007 XK calls for a 5W30 that complies with Ford WSS-M2C913-C spec. It appears that oil is not available in the U.S. All Castrol Edge, Mobile One, Valvoline SynPower, etc are U.S. Spec only and don't list compliance with Ford WSS-M2C913-C (or A or B). What oil that I can buy in the U.S. Should I use??

Govtslug

 

Unless you know what was put in the car from the day it was purchased I would say any of the oils you listed would be OK. If you want to see what is being used currently just give the dealer a call and ask the service tech's what they use.

 

Thanks. I'm probably just being way too **** about it. My guess is any name brand full synthetic is probably fine, especially if you change the oil every 7500 miles or so.

Govtslug

 

Did you know Dr. Hass is a dental surgeon or dentist? Forgot which.

Everyone quotes that article as if it were gospel. Don't be misled by the
inappropriate use the the honorific.

 

GovtSlug, all the ford spec refers to is a fully synthetic oil and my owners manual just specifies API-SM or ISLAC-GF4. In 2007 those were the current specifications and since then new standards were added to API-SN which supersedes SM and ISLA-GF5 which supersedes GF-4.

So any of the current synthetics will be perfectly fine. I added a link to a chart from AP on page 2 that lists the current synthetic oils and specs.

Been using Mobil one in my 97 and was going to use in my 07 but I tried Castrol 0-40 and actually thought the car sounded much quieter and ran smoother than it did with 5W-30. Not sure if it was Mobil 1 in the 07 as this was my first change in this one.

I was looking at at 0w for cold weather starts as it gets pretty cold here in the winter and according to my research the Castrol 5W-30 wasn't the best for cold weather starts. Like you probably just over analyzing (notice it starts with **** )

And I agree with plums in regard to DR Haas, it's a good read but by no means a bible even though I found tons of sites that referenced it in one way or another, even Bobs the oil guy used it.

My owners manual lists 0W-30, 5W-30, 0W40, and 5W-40 so I will stay in that range. The main thing that started this for me was that the owners manual stated that the 30 weights didn't provide protection over 95 Degrees and the 40's protected up to 122 Degrees. Summers in Chicago get hotter than 95.

Go Hawks!!! We've got the Cup

 

Interesting; the UK manual for my MY11 lists Castrol 5W-20 only.

 

I was going to try the Castrol 0W40 but I haven't checked to see if it's available in the 5 qt jugs for a better price. I've been using Mobil 1 0W40. When I first got the VDP it had a fairly strong oil pan leak, but after 5k miles on the 0W40 it has completely stopped somehow.

 

For the summer months at my CA locations where typical temperatures are near 100 F, I plan to use oil viscosities that are heavier than the factory recommended values. I don't think that engine tolerances or constructions have anything to do with the choice of oils.

In making recommendations for specific oils manufacturers have to take into account a huge variety of locations, conditions that their cars may encounter. The oil must stand up to the worst freezing conditions in parts of the world and to the highest temperatures in other parts.

In the case of my '15 Stingray the general factory recommendation is for 5-30W Mobil 1. However, for track use, they recommend 15-50W oils, indicating that for the higher thermal loads encountered under track driving conditions the 5-30 would not provide sufficient protection.

Since I enjoy winding out my engines at the local canyon roads even during the summer heats, I am quite certain that I would be better off with going to at least a x-40 W oil during the summer months. The same oil, realistically, should also be OK during my mild CA winters where it never drops below freezing during daylight hours.

 

The 5L engines in 2010 and up are different from the 4.2 from earlier years Ngarara.

In my research I know I saw something where you are not limited to Castrol but don't remember where.

Torrid, both the Mobil1 and Castrol Edge are available in 5qts at my local store in the 0w-40 so that is what I'll stick with as neither are available in 0W-30.

 

The OEM already takes that into account with recommendations for hot weather operation. Why do you believe that this is not adequate?

 

Because in my decades of racing experience I would agree with GM's recommendations for x-50 oil viscosity for track or hard highway driving (autobhan, steep canyon roads in low gears, etc). The OEM recommendations are for non track driving for an ultra wide range of usage. If you will use your car in very high temperatures under heavy RPM loads you are much safer with a higher viscosity oil. For normal driving even a 0-20 W oil will do up to about 100 F. A 20-50 W oil will be effective up to 300+ F of oil temperatures, something that the 0-20 oil would not stand up to effectively. With cars, such as the supercharged XKR, oil temperatures can shoot very quickly towards 300F while doing some near redline driving over steep canyon roads. Most manufacturers do not provide enough oil cooling capacities for such driving so the only safety valve is to use the higher viscosity oils that stand up to those temperatures.

 

here you go:

https://www.jaguarforums.com/forum/g...7/#post1249686

 

DpezXK8 - So its been over a year since you put in the Castrol 0W-40, did you decide to stick with it, or did you you switch to something else?