If a car has Mobil 1?
 

Should I stick with mobil 1. I think the corrado had synthetic 10w30 in it and the p/o wont email me back? I have a few old receipts in the book he gave me and it appears to have had mobil so should I stick with that or put it on castrol like I run in everything else?

I doesn't matter - all the store bought have essentially the same additive package, base oils are different is about all. It used to be a compatiblity issue many moons ago - not the case anymore. Mobil 1 maynot even be the PAO based oil it used to be, ExxMo used Group III mineral base stocks which match up pretty close to PAO but can be cheaper (depending on the month).

What year is your Porsche/car?

From personal experience:

I had an 86 911 for 4 years. When I first got it, it had been maintained with Mobil 1. The car was 17 years old. It "wept" oil a bit...small leaks.

I switched it over to Rotella T, non synthetic and the weeps stopped and the car stopped leaking.

I then bought a 993, almost 10 years old...again serviced consistantly with Mobil 1. I continued this for 3 years, and small leaks began to get a little bit worse...leaking just a little bit from various spots on and around the engine....

I kept Mobil 1 in there not wanting to change...but after having the thing with the 86....I decided 6 weeks ago to switch to Rotella T on the oil change.

The leaks stopped.

All I can say is that in older Porsche engines...Mobil 1 may be too detergent to run in an engine without it causing some small leaks... with 2 911s, I switched to dino oil and the leaks stopped.

Has more to do with the solvency of the base oils and the plastisizers in the seals.

No this is in a VW Corrado with about 102,xxx miles. So am I fine to change it to castrol?

you mean Castrol Regular Dino oil, not synthetic? If so, I wouldn't. Only reason I wouldn't use synthetic is if it leaked like crazy.

What do you think Lube

Ya basically I am asking about switching from synthetic to regular oil.

Ok to switch from syn to dino. Not ok to go the other way on a high mileage engine. The syn will leak out because it tends to clean up the gunk that holds the seals together. That's the theory but I have also personally BTDT.

George

uhhh...OK.

There are lot's of good reasons to stay with synthetic. Flows better when cold, less friction, higher flash points, less sludge, longer oil change periods. 102k on a car thats been using synthetic oil is just broken in, IMHO. I would stay synthetic if only to enhance the resale value.

If you catch it on sale, it's not that much more than Castrol GTX would be.

I used to use Mobil 1 in everything, but it's got a bit more pricey lately. Based on what Lubie said, I'll consider the other brands. But dang, I was in Walmart last night and their Dino oil house brand was over $2 a quart. Nothings cheap any more.

BTW I have tried at times different full synthetic oils, and the only one I had a negative experience with was the NAPA House brand. It seemed wrong from the first pour, and I wouldn't recommend it at all.

Just found a rather lengthy article which had lots info I hadn't known before. Worth a read.

http://www.boss302.com/oil.htm

I ran full synthetic for 200k in my Fjord 4.6 (F-150). Everything looked brand new in there, when I had to fix the head gasket at 202k miles. :(

What I am saying is - you may preserve that engine nicely, while the rest of the car falls apart anyway. On an average "drive into ground" daily driver, synthetic is a waste of $, IMHO.

George

I like the GTX - do it and be done with it. Now, were did I put that legs and butt thread???

I love it when you talk dirty!

There is no doubt that the synthetic is superior oil... actually what im using now in the 993 is Delo 400 which is a desal oil....not synth...but it is helping to stop those leaks and that is more important to me right now. I will just do more frequent changes with the Delo.