My new (to me) '98 SE has 167k miles on it currently. The original and previous owners have only used Mobil 1 for oil changes. I plan on having an UOA done. In the meantime, what do you guys suggest? Should I stick with M1, try some dino oil, or another synthetic? I've used Castrol GTX in my last maxima with good results, but I would like to try extending my oil change out to around 10k miles if possible.

I haven't looked thoroughly under the car for leaks yet, but it looks ok. I have some leaking around the valve covers (big surprise there) and some on the timing cover area. Haven't had the car long enough to comment on oil usage though...call this a general inquiry.

 

If the previous owners were using Mobil 1 and you want extended drain intervals, why would you consider dino oil? Do you think any of the leaks are seal related? If so, go to auto-rx.com and try their product.

I can't recommend an oil for you. I use Esso Extra XD-3, 0w30, PAO, synthetic oil where I live in British Columbia. I don't think this oil is available in the US. I believe WalMart may carry 0w40, not sure about 0w30. It is a superior oil compared to Mobil 1 based on UOA and VOA analysis and where I live is only about 2/3 the cost.

 

u can find 0w-40 @ walmart. i buy it for my BMW Z3, it is the so-called "european car formula" I think u will be fine with M1 10W-30 there in Texas. If u switch to dino oil u may develop leaks due to the molecular structure. it's not worth the money difference. I had my M1 analyzed in my Z3 by Blackstone lab. They stated I had "plenty of life left after 3k miles. Im sure you can go at least 5k miles maybe closer to 7 or 8k between changes. It is worth the money

 

WHAT? at 3k Mobil 1 or any synthetic is just getting started.

I am considered conservative draining my 0-W40 Mobil1 at 7500 miles. Someone who drives mostly highway and drives their car easy until it warms can easily do 10,000 mile changes.

As far as UOA um, pick whichever oil you want the lab to give you information on? Why would you submit Mobil 1 to get UOA if you want to use Castol???? They analyze the oil not your car.

 

You're bound to have leaks and whether its dino oil, syn oil, if there is a leak, there's a leak. The car has a lot of miles on it, but more so, you're unable to validate whether or not mobil 1 was used.

If you care, FIX THE SEALS and use whatever oil you want.