Hey guys I'm trying to decide should I go with 5w30 Mobile 1 synthetic or the Mobile 1 high mileage synthetic oil. My STR has 87K miles on it, so I was leaning towards the high milage Mobile 1 synthetic. Only thing that concerns me is that it contains conditioners and some other stuff for the seals and gaskets in the engine but is that safe to use on the STR engine?

I hate to open the pandoras box on this issue but I just wanted to get some feedback on what others think about this .

 

No burning oil. No leaks. No "high mileage oil".

End thread.

 

A two (2) post thread on which oil to use (excluding this one)? That would be one for the Guiness Book of Records.

Bob S.

 

Shazam! (and agreeing with ChrisSTR) plustheusualsyntheticsareofnobenefitasidefromlonge rliferant

 

LOLz, well hey my car is burning some oil, but considering the high mileage you still say don't use the MObile 1 High mileage oil, and why not? A better explanation would be appreciated

 

If it's burning oil why not change to a thicker viscosity?

 

Which thicker viscosity do you recommend in synthetic that would be suitable for the STR?

 

I run mobil1 10w40 since we have had 100+ temps now it's cooling down at 5000 miles I'll switch to 10w30

 

None. Do it right and fix the engine.

 

Yup...

What makes you think it's burning oil?

 

And... how much is it burning in how many miles?

Gutted to say mine has started burning some. Had to top it up (from the min to the max) after 5K miles from the last service

 

deleted - double post

 

jag79, I'd go with the high mileage synthetic for now...One day all of us will require a rebuid.

 

well all engines burn oil, the rings on the pistons have a gap. so oil seeps :-P how much oil it burns is another story.

 

Sorry, but using these miracle bandaids in a can oils is verging on Bubba to me. This is a high dollar, high performance, semi-exotic luxury car. High mileage oils were meant for Buford to get an extra few thousand miles out of his rotted out pickup before the frame snapped in half (again) from rust and overloading. So is substituting a different (and non-recommended) viscosity.

If it really is burning and not leaking oil. Determine the root cause and plan to address it. That's part of the cost of owning one of these cars.

[/rant]

BTW, using synthetics in a car with high oil consumption is an even bigger waste of money.

 

Yea, mine goes through a quart every 5k to 7k miles as well. Granted it is a 3.0 not a 4.2 so not apples to apples comparison. I remember asking the dealer about the drop and they said that was about right..

That's why I asked "what makes you think it's burning oil". Hey, just be glad it isn't a Dodge 3.8 v6...That is one thirsty puppy...But, then again the factory spec is 5w-20 oil...

 

These engines, have a wide spectrum of viscocitys they can run, mainly tempratures.

The tolerances inside the motors change in different enviroments, so you HAVE to compensate as the engine begins to wear, which is almost after break-in.

It makes logical sense that as the engine milage increases so should the viscocity of the oil so long as you are within the temprature threshold of the oil.

I would never recommend running a 20w50 in sub zero temps. you will oil starve the motor.

but jumping up a couple viscositys because you no longer have the same tollerance/clearance as a shiny new motor makes sense. something has to take up the gap.

The Bottle miracles are doing the EXACT same thing. pour a bottle of lucas in your oil and you made the oil more viscous in effect giving you illusion of a "tighter" speced engine.


*Ducks from the bashing*

 

If you read the owner's manual, it even states that it will use about a quart in between oil changes.

 

Read the ... wow, what an idea!!

 

Actually no it doesn't. Here's what Jaguar says:

Recommended engine oil
(continued)
When the oil level is at the lower dipstick
mark, add 1 quart (1.0 litres) of oil:
Oil specification – API SJ/EC and
ILSAC GF–3
When topping up between oil changes,
make sure that you use oil that has the
correct quality level (API service) and
viscosity grade. Your vehicle’s warranty
may be invalidated if damage is caused by
use of improper engine oil.
For maximum fuel economy, 5W–30 oil is
recommended.
SAE Viscosity Rating
For climates ranging from –22°F (–30°C)
and +122°F (+50°C), the following oil
viscosities may be used:
0W–30
5W–30 (preferred)
0W–40
5W–40
Note: It is recommended that the oil level
is topped up using oil of the same
viscosity. If you are unsure which oil
viscosity is used in your car, your Jaguar
Dealer will be able to advise.
If you are operating this vehicle in
climates outside the above temperature
range, contact your Jaguar Dealer for
advice.


No mention of going beyond 5W-40, and nothing about moving up the scale with older engines. If critical clearances were excessive, oil pressure would drop. There is no reported low oil pressure, nor would a thick oil 'fix' the problem even if there was. If it is a valve seal that is allowing excessive consumption, thick oil wouldn't help that or fix it either.

Sorry, second guessing OEMs by using shade tree engineering logic rubs me the wrong way.