Hey guys im gonna do a little tune up on my xjr today, and was wondering if you guys think i should switch to synthetic oil, instead of regular. And do you guys have a specific oil brand you use? thnx

 

a classic debate. Jaguar did not put synthetic in from the factory, and some people (dealers) do not recommend its use. I have owned cars in the past where synthetic is not recommended because the individual molecules in the oil are actually smaller, and consequently can penetrate seals easier.

However, for the vast majority of cars, this is not the case and the only thing you will do is make your engine a little happier.

To the second part of your question, I use Valvoline.

 

Synthetic oil is the best oil for use in the car. It costs more but it lasts longer. It does this by being more stable at higher temps. It also does not need viscosity modifiers dumped in it which adds what I call "rubber" into the oil. You can extend the change intervals some and the engine will be better lubricated during the time. I would change the oil every 7500 miles with synthetic, 5000 with conventional.

 

Jaguar actually specified synthetic oil exclusively for use in Mexico (and similar hot climates ) for my 1999 XJR. I have used Mobil One 5W40 for over 100K miles, 5K oil changes, Purolator or Jag OEM filters. Nothing but happy motoring thus far.
Having said that, I switched from dino oil to synthetic in my wife's Audi A6 at about 80K miles, and it did develop a minor oil leak at the secondary timing seal, but I can't confidently say that was due to the switch....Went back to the dino oil in it a couple changes later. Still leaks a bit (and makes a bit of foul smell) but runs fine 60K miles later.

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1999 XJR

 

Well thank you all for your awsome feedback. I am gonna go with regular for my first oil change and maybe in 5thou i will go to synthetic. thnx again