I've got to chime in and agree with Sam on the darkness factor. I attended a lecture from an oil company executive who agreed that the darkness is not an indication of when to change your oil. It's doing it's job.

On the first question that started this bruhaw, I've been using Ford FL2021 longlife filters that are sold for the LS. Top of the line as far as I know.

 

Here's an interesting observation about the color of oil. As well as my 2003 XKR I also own a natural gas Honda Civic. The oil change schedule on the Honda is 10,000 miles (no special requirement for synthetic) and the oil is almost as clear after 10,000 as it was when it was put in! Since natural gas has only one carbon atom and four hydrogen it figures that with such a clean burning fuel, there is very little carbon in any blow-by past the pistons. I suspect the engine will probably last a lot longer too with less abrasive particles in the oil. Many years ago I owned a C5 corvette which would tell you when to change the oil based on some algorithm. No idea what parameters were used but it seemed to work! Why don't more cars have that? Engines may last longer.

 

I'm only just out of weeks of therapy after hearing how little you pay for fuel in the US. Now I've see the price of Synthetic oil in this thread and I'm back into depression.

Picked up 2 x 4 litres of Castrol Edge to do an oil change this weekend and it was £70 - that's $110.33

Graham

 

I have owned 3 vettes and have never seen that, all mine say is to use Mobil 1 Syn. and change at regular intervals, forget the actual miles, I think 7,500.

 

I had a Mini (ok BMW) where the manufacturers recommendation was whenever the computer tells you or once a year, whichever comes first. If I had followed the clock it would have been 15k or more between oil changes but I always got to a year first.

This made me pretty uncomfortable in the beginning, but after 90k miles of "once a year whether it needs it or not" car was just fine.

Modern oil + modern cars + good filters makes long intervals possible.

The Jag I do at 5k.

 

My Dodge Grand Caravan tells me when to change the oil, but I don't listen. A blinking signal comes up in the dashboard saying, "Change Oil". I have to turn the key partly on and press the accelerator to the floor three times to disable it. I change it a little more frequently than it tells me to.

 

lubricationability..lol how about carbonacality

 

There are a couple of factors to consider as to when to change your oil. What is the temperature range of where you are driving as well as the driving style that you use. The higher the temperature (Phoenix Arizona) will cause oil break down a lot faster than lower temperature (Seattle Washington). If you drive the car hard verse driving the car easy. I was a mechanic for 36 years (retired now). I have seen the effects of different types of oil and frequency of oil changes. They long term effects are not always appearent but can be seen when the engine if finally taken apart for repairs. Number one thing I can tell you for sure: No Penzoil! Personally I use (as well as 90% of all mechanics I know) use Valoline. I do change my oil more often but I like a clean engine if I ever have to take it apart.

 

I split my time between the UK and the USA - (the XK8 is my US car) and one of the first things that struck me was how cheap engine oil is in the U.S.- the UK does impose VAT at 20% but that still doesn't account for the difference.The difference in petrol prices I do get - much more excise duty in the UK.Obviously the oil companies know why- but I bet they won't explain.Only consolation for you,Graham,is that Jaguar spares are mostly cheaper in the UK.

 

Agreed,

With engine oil in the UK, it's a situation where 'market forces' appear have crossed the line to 'cartel'.

On balance, it still has to be much cheaper to run a Jaguar here than in the US. When I read about US parts costs for Jaguar OE on the forum they can often be up to double the equivalent of here.

Graham

 

I'm sure it's only coincidence, but that's been my car's steady diet for the last 5 years, though now she is getting a 'high mileage' formula.

 

Had an interesting conversation today with a mechanic who works mainly on BMW's and MB's. Also does other Euro cars. Asked him to quote me on replacing timing chain tensioners for my 99 xk8 as a preventative measure. He said he would not do it but said if you change your oil regularly and use an OEM filter they should not need replacement. He stressed the OEM filter saying that cheaper filters let the oil bleed out of the filter and upon start up there is some oil starvation until it gets flowing. With the OEM filter there is a "check valve"? in the filter that makes sure there is oil available immediately. I have never heard of this. He also said he uses LIQUID MOLY exclusively. I certainly dont mind paying for a premium oil and filter but wonder if anyone else has heard of this thing with the filter. Thanks

 

I would treat that advice on the tensioners with extreme caution..............unless he was giving a written guarantee. There's too many evidential reports of tensioner failure and near misses on well maintained V8's here on the forum.

Did he say "should not need replacement" or "will not need replacement"? There's a big difference.

The information about OE oil filters is accurate. They do have a non-return valve which is omitted on several aftermarket filters.

Graham

 

Run for the hills.

How does he explain the thousands of owners who faithfully had their cars serviced by the main dealer right on schedule or earlier and still had problems?

 

I agree with the others, the filter info is correct.
The tensioner failures are not generally caused by oil or lack of it.

 

Just bought Mobile One from Walmart for $23 per 5 quarts! Shelf sticker said $25 but at checkout was $23? A first for Walmart.

 

I understood the valve in the filter was to allow oil to bypass the filter if it became blocked . Ay one else heard this ?
However the Mobil site does say it stops "dry starts" caused by an empty filter.

 

All fiters or engines have a bypass provision for obvious reasons. A check valve that keeps the filter housing full while the engine is stopped is required on engines that have the filter installed in other than a 'gasket side up position'.