Macster

in my 03 Turbo, going from Mobil 1 0w-40 to Mobil 1 "high mileage" 10w-40 not because the Turbo has that many miles (just 17000 miles now and 4100 miles since last oil change) but because I wanted to see/feel/hear what if any difference a heavier "w" oil would have on the engine.

Too early to be sure, but the engine sounds quieter. Less clatter on startup and I believe the engine has a smoother idle as engine warms up a bit. When I first got the car I was a bit amazed at how out of tune (best I can describe it) the engine sounded upon startup.

By comparison, my 02 Boxster is much quieter at startup. Sure, the engine emits a bit of noise right at startup from a bit of cam chain dragging but the engine quiets down in just a second or three.

Really, the noise is very very brief. But even though cold the engine is smooth. (One co-worker compared the engine to a sewing machine it's so smooth.) Sure, the engine's running at a fast idle, but so's the Turbo engine.

Anyhow, the Turbo engine with this 10w-40 oil though only after just a few starts -- none from "cold" yet -- sounds much better. Tomorrow (Monday) morning after car sits overnight and will be at ambient temperature I'll get a chance to hear it from a colder start. Area in the beginning of a hot spell though, and night time temperature will probably be lucky to get in the low 60s at night though will climb with temps later in week forecast to be 100 during the day.

I'm going to run the 10w-40 oil until 20K miles then change over to Mobil 1 5w-50 and see what if any differences I notice. Might then stick with the 5w-50 oil but the 10w-40 oil seems to be a pretty good oil. And I use it in my 02 Boxster. 'course, I guess I could use 5w-50 oil in my Boxster. In fact next time I change its oil I'll use 5w-50 oil and note any differences, changes cause I have lots more experience starting the Boxster engine in all kinds of conditions.

Sincerely,

Macster.

Dock

Is 10W-40 an approved oil weight for the Turbo?

wross996tt

10 weight for start-up is too thick...perhaps you should read up on what the dual weight system is...you don't want the cold oil weight (the first number) to be viscous as it prevents the oil from flowing where it should. I don't know why folks think sound is the way to judge the performance of oil. It isn't.

ltc

IIRC, no.

Macster

10w flows quite readily at cold temperatures where I live. In fact, for several years I used a 15w-50 oil -- only oil available -- in my 02 Boxster even in the mid-west winters with no ill effects.

Another factor to consider is a 0w oil can flow away from oil spaces more readily than a heavier 5w or 10w oil and thus make a the 0w oil part of the problem a quicker flowing oil is intended to address.

Startup sounds is one way to judge an oil's behavior. Less sound upon startup is less wear and tear. The noise indicates more contact of a wear inducing nature taking place.

Sincerely,

Macster.

Macster

This is not clear from the owners manual. My 03 Turbo manual lists 0w and 5w 40 and 50 oils for temps generally higher than 50F and 0w and 5w-40 oils for temps generally lower than 50F.

However, underneath the chart it reads "... and viscosity grades of SAE 0w-40, 5w-40 or higher" which I interpreted to mean I could use either a 10w-40 or a 5w-50 oil as long as said oils also meet the stated API or ACEA classifictions listed by Porche and both Mobil 1 0w-40 and Mobil 1 10w-40 do that.

(Another document from Porsche -- an approved oils listing available from Micke Focke's pages -- does not list 10w-40 oil as being approved. However, IIRC and without taking the time to go down and fetch the owners manual to confirm my memory, 10w-40 and 15w-50 oils were approved for use in my 02 Boxster at one time and Porsche has since issued new approved oils lists that remove these oils.)

I'm going to run this oil until 20K miles (around 3K miles) and then switch over to 5w-50 oil and probably run with that year round.

Sincerely,

Macster.

Dock

I interpret this to mean higher than 40, and not higher than 5.

I wouldn't assume that just because a certain weight oil is approved for the Boxster, that it would also work in the Turbo.

Michael-Dallas

+1

I like AE Haas' line of thinking when it comes to oil. But I won't go outside the boundary of what the owners manual recommends.

If you're going to play w/ oil outside the weights recommended by the owners manual, then you should definitely get oil analysis performed and start trending it.

///Michael

wross996tt

Read the Oil TSB for approved oils...and there are NO 10 weight oils on the list (if you need the TSB go to Renntech.org)...but hey it's your car...LOL

Dock

Have you ever run an engine (any engine) that was either low on oil, or out of oil, and listened to what it sounded like?

wross996tt

Dock, I am not inferring that unusual sounds don't provide great insight to potential problems. What I am saying is you can not infer the performance of oil based solely on sound. If you want to find out whether the oil is performing, you will literally have to take the engine apart and inspect for wear. I think your example is quite extreme...and no I have not started my car without any oil in it. Have you seen cars have noise issues where it was not oil related? Have cars failed when no unusual sound was detected?

In any case, are you suggesting that if the car sounds quieter, that the oil is better?

Dock

Sorry, I didn't see where you previously used the word "solely" in this thread.

Define "better".

Dock

Yes.

And I've seen cars with noises that were oil related.

wross996tt

Actually come to think of it, I went to a demonstration for a product called "slick 50" some years ago. They added the slick 50 then removed all of the oil from the motor. Started the motor back up and it ran for hours...with NO sound...perhaps you should do that Dock.

Dock

is Slick 50 on the Porsche approved list?