your right

 

Correct,

15k changes or every October. lately its been around 11,000 miles a change by the time October (change it yearly, just did it last week) comes around.

Mobil 1 EP 5w30, and a standard Purolator oil filter each time.

I won't go into it again, since I already posted a long winded explanation on a different synthetic oil thread, but for the past 30 years or so, my entire family has been doing yearly changes on the stuff. We have had several vehicles in the 200k to 250k range that we sold running well, with no issues, that had yearly oil changes.

The stuff has a warranty now that protects you from any oil related damage or failure to your engine, for 1 year or 15k changes.

I've also had oil analysis done at the end of one year and the oil was deemed to still be within usable bounds. Mercededs does 10k changes with there cars with M1, its in the manual, and overseas they have had long drain intervals for years with there cars. It's just the US thats behind. It's an industry.

Anyone thats done work on an M1 engine will always agree, even at high mileage, the engine is clean and tight.

I personally just enjoy changing the oil once a year @ $40 or so.

 

quote "donkeypunch"
"Here is where it gets interesting. Some of you have mentioned that you have ran a conventional oil for many thousands of miles, and then switched to synthetic, then had problems. Many of the problems are related to the cleaning agents in the full synthetic. Sometimes, you can develop an oil leak at a crank seal, and never notice it with conventional oil (ie: leaking oil becomes extrememly dirty and becomes a stop leak at the seal. Then, when you get oil thats worth a f&^%, it cleans out the dirty deposits, therefore, re-opening the original leak. Synthetic motor oil does NOT create leaks."


So if the syn cleans up your motor gunk, what about using a "stop leak} product when you put in the syn.

 

Thanks for all the great info. Sounds like Castrol or Royal Purple is the one to go to.

 

Personally, I hate "stop leak". Mobil 1 makes a full synthetic high milage oil that is awesome. Basically, for the same price of buying the standard Mobil 1, you get that plus the high milage additive package in the oil. This will help keep the oil seals soft and plyable (less subject to becoming hard and brittle). I run the Mobil 1 full synthetic high milage in the Dak.

 

I've been running Pennzoil platinum 5w30 for the past 25k. Changing every 7K. Think I'm going to up my interval after reading this post.

I also tried switching to syn on my high mileage car (380K miles). It was leaking too much oil - switched back to conventional.

 

i maybe switching to mobil 1 for my next change seeing as it seems to be the most recommended here. question though i noticed monkey says he uses 5w30 when the manual recommends 5w20 is this a big issue or is it a preference thing

 

so what are the chances I will start seeing leaks at 60k if I have been using conventional oil (5w-30 penzoil) to this point and I switch to synthetic? What defines "high mileage"? Is it 75k for synthetic like it is for conventional?