I have a 2002 jag x type 2.5.. in my manual it says jag does not recommend synthetic oil in the v6 engines. im confused because i thought you were only supposed to use syn oil...

 

Many people have used synthetic oils in their cars with no issues. With the early cars, there was a fear that the full sythetics would affect the VVT system negatively. Time has proven this to be false. So, if you feel that you want to use sythetic oils, go for it. As for the benefits, that is a completely different argument.

 

synthitic oil more likely to leak since its a smaller particle than conventional oil is what I've heard

 

Doesnt recommend and "do not use" are 2 differant terms

 

I only use synthetic and have had 0 adverse effects.

 

If you look at the 2003 manual, the warning against synthetic has disappeared.

Data sheets for Mobil 1 5w-30 show that it conforms to the specs given, I assume that others do also.

 

But are you protecting your engine better if you use synthetics, or are you just wasting money? My manual recommends castrol 5w 30 and warns against synthetics. I have an 05.

 

Are you sure?
Here is the relevant page for a '05 X Type downloaded from Topix

 

harryc, the amount of "better" coverage by a synthetic oil has recently become a hot topic. I would recommend that you first find out which oils that are called "synthetics" really are a blend or whatever they are. Then I would next look into the "better" side of things. For some, this is a big thing, for others it isn't and doesn't justify the cost. Synthetics could be very good for those people that drive tons of small trips (2-3 miles each way, motor never really gets up to temp). While others that put tons of miles on their cars may not benefit from the special properties of the true synthetics. The general concensus from the Forums is that whether using synthetics or traditional oils, the car is going to get about the same mileage. So, now the question is, do you feel that you are getting adequate/better protection in your engine for using said oil? I see this question as a "what is your favorite color" question. We all have a thought on this and no one person is correct.

 

I've been using Mobil 1 in all my cars for years and years. I do that primarily because of the extended interval for oil changes. With dyno-lube I'd change oil/filter every 3K miles. With Mobil 1 I extend that out to 7.5K miles.

Been good so far, however I typically don't end up with high mileage on my cars. I usually end up with something new when my current ride reached ~120K miles. So I can't comment on high mileage engine longevity.

That's my story and I'm stick'n with it...
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Jaguar - it's not an automobile, it's a Motorcar

 

As a former NASCAR mechanic I can tell you this, the engines we had in the race car after 500 miles with conventional oil were in really nasty shape, nearly every internal component needed replacement. When we switched to Mobil 1 at the 500 mile rebuild the engines looked brand new inside.

Does that mean it will make a big difference in a street car that doesn't work any where near as hard? No, but it can't be any worse than the conventional oil.

I use Mobil 1 on all my cars, and change the oil every 3 - 5k, the Mobil 1 comes out looking nice and clean, can't say the same for the conventional oil I used to run.

 

Just double checked the manual. It does indeed say castrol 5w 30 and that it does not recommend synthetics. I'm in the states if that makes any difference.
Also I just called the dealership and spoke to the mechanic. He said that you can use synthetics without a problem but isn't necessary.
I ha e 56k miles on my jag, and I would be afraid to switch now. The car is use to one type of oil. Why tempt fate?
Btw I used conventional in my 02 mustang for 7 years and sold it with 150k miles on it, and not one single breakdown, not even a flat tire. I do have a habit of changing my oil on or before 3k miles if that has anything to do with it. I also drive like old people screw, slow and careful.

 

This is one of those topics that could go on endlessly with no clear answer either way.

I use Castrol GTX 5w-30 in my X.

 

I use a blend and my 03 AWD V6 runs fast and smooth!

 

I'm using regular oil & looking to go synthethic. They say when you start using synthetic it is bad to switch back to regular. Is this true?

 

That used to be the case with the early synthethic's, not so much anymore.

 

My 2003 manual says nothing about Castrol oil or synthetic oil. All it says is recommended oil is 5W30. I've been using Castrol synthetic since buying ours in 2007 when it had 58,000 on the clock.

 

plain old cheap store brand oil for me

in my opinion there all do the same job
ive had freinds who dont even chage there oil with over 200,000 miles on there vehicles

point is change every 5000,

 

I have been using synthetic oil since my car was purchased @ 24K miles....I'm at 91K now and I have had no issues at all.

 

I believe that the frequency of oil changes will protect your engine more than the brand or type of oil used. If the oil is changed every 3 to 5k then there's little chance for viscosity breakdown.
Also, engines tend to be designed around specific oil and gasoline combinations. So while synthetic, while technically superior to conventional can be used, there is probably no increase in the longevity of the motor.
Of course if you drive like a maniac it could help, but I would be willing to bet the drivetrain would fail before the motor does.
Some cars like the corvette require synthetic to function. Our cars will run just fine on normal oil, but you're not hurting anything if you decide to upgrade.
It's not a lot of extra money to spend on a little peace of mind.