How often do you change Mobil1?
 

I changed my oil and used Mobil1 after many endorsements, including an ex-engineer at Mobil. On the bottle it says it's guaranteed for 1 year or 15K miles whichever comes first.

Do folks in the 911 world abide by less frequent oil changes?

I've been changing it every 3000 miles. If the Mo1 is as good as they say then it be great to change the oil with every valve adjustment.

Thanks

I am still changing my Mobil 1 every 3k, I feel that it is a cheap insurance by still changing every 3k miles. JMO

I change mine every 10000 km (or 6200 miles). Usually works out to about once a year for me.

I think changing it every 3000 miles is unnecessarily frequent unless this is purely a track car or something or you only put 3000 miles a year on it.

Mike

On my 993 I change it every 5000 miles. Recently though, 15/50 or Extended Perf. (whatever they call it now) has become near unobtanium in these parts.

What IROC said.

Ditto Iroc

5000 miles or 1 year, whichever comes first...

Every 6200 on carburated, CIS, and EFI cars is probably fine. Mechanically injected cars need it more often (I am told).

Apparently, EFI cars tend to have more fuel dillution and therefore eat up the oil faster. I am going to have my Mobil-1 analyzed out of my EFI car to verify or rebuke such claims.

Eevery car is different so used oil analysis (www.oaitesting.com) is the proper way to determine the proper drain interval for your car.

Don

On my 69E the factory recommendation is every 6000 miles at which time you also adjust the valves, change spark plugs etc. With Mobil 1 changing every 3000 miles I think is overkill. Remember in 69 they didn't have synthetic available. There is a study of synthetic oils on the internet by some enterprising racers wwho checked oil samples after every 1000 miles on their road Camero not a race car. Mobil 1 went 12,000 with no oil or filter change until the insolubles got to a point where harm could occur. They changed filter and topped off the oil because of the filter change and went 6000 more miles before they stopped the test because the oil was wearing out. They then did a oil change and started a test on Amsoil. Pretty good stuff.

Did 10k changes on M1 in my '85, and will now be doing 3-5k changes on dino in my '72.

If it buys you peace of mind, it will be a placebo effect, according to the literature out there...You are probably not remotely reaching the reserves of the oil. I tend to think of 5k as being the early, conservative, essentially soonest point at which you would want to change synthetic in typical use, unless you are involved in rev-limiter research or something...IOW I haven't heard yet of any benefit of early changes, other than a warm fuzzy feeling.

To all,

Very good info. Thanks. I'm going to enjoy not changing it so often.

I changed mine once and never used it again!

Craig

The 3000 mile oil change was a product of some marketing people at a motor oil company in an attempt to boost sales. To follow their logic if 3000 changes are good, aren't 1500 mile changes twice as good?
I just put mobil one in my engine about 500 miles ago, I'll change it next year.

Once a year in my Porsche (works out to about every 3,000 miles).

In my G35, every 7,500 miles.

BMW changes the Castrol Syntec every 15,000 miles in our X5!

I would be surprised if the stock EFI dilutes the oil.

Use Porsche's service intervals -- and change it every year if you don't drive it much.

I agree that 6k, 5k etc. is a waste of oil and money. It won't kill you to do it more often - just be sure the oil is recycled.

If you guys have that much extra energy tho, it wold be more socially usefull if you'd come on out here and paint my house for me....

hmmm. when its black...

Once a year or 3,000 miles, whichever comes first...Usually it's time related.

...and tart to the taste :D

Too often,

I bought the car 1 year ago and already changed the oil 4 times.
I put 3500 mile in that interval.

I guess I get bored and start doing something. Changed the plugs
3 times as well.