stuttgart1

I just change the oil on my 99 Boxster with Mobil 1 10w-40 high mileage. I realize a noticable different on the sound of the engine after the oil change. Engine sound is more high pitch at high RPM especially after 5,000rpm. Has anyone used 10w-40 HM on their M96 and notice any difference? I am not sure this is normal or bad, I am considering switching back to 0w-40...

smlporsche

I don't know where you live but as we go into the colder months the correct weight oil (0W-40) will help reduce engine wear, particularly on start up...which is when most engine wear occurs.

Macster

I'd like to think I've noticed a difference between 0w-40 and 10w-40 oil regarding engine noise at startup but I really don't think I have.

At any time other than a cold start both the oils are nearly/practically the same-- both are "40" at high temperature, at the operating temperature of the engine.

As an aside, the engine will be noisier upon a cold start after having sat unused a long time. I seldom let my Boxster sit more than a day unused, but the few times it has sat for longer periods of time upon startup it can be a bit noisier. Nothing out of the ordinary though and the engine quiets right down. (Even though it now has over 225K miles on it.)

The biggest difference I do note is changing from oil that has 5K miles on it to new oil. New oil, be it 10w-40 or 0w-40, is a quieter than the same oil with 5K miles.

I've run Mobil 1 10w-40 in my 02 Boxster now for tens of thousands of miles (from 100+ deg. F. to near 0 degs. F. ) and I have not experienced any problems. Unless you live in an area where ambient temperatures reach lows that fall into the extremely cold range at which a 0w oil required the engine will be ok.

Did you leave the oil cap off, or loose? Did you under fill or overfill the engine with oil?

Does the engine start out quiet or get quiet real real quick, like in a second or two after even cold engine start? If so, I don't think you need to switch back to 0w-40.

Sincerely,

Macster.

stuttgart1

Thank you for the inputs! I live in California so temperature rarely gets below 50 deg. At first I thought I overfilled the oil, so I drain out half quart last night and now it is slightly below the full mark (1bar from full on the electronic gauge).

I am curious, when the M96 engine hits high RPM does it turn to high pitch like buzzzz sound? Before it was a more solid sound, especially after passing 5k RPM.

I acquired the car recently so I don't know what kind of oil was previously used. Sounds like I should be fine if there are many of you using 10w-40 but I just want to see what is consider "normal" sound of the engine.

stuttgart1

The engine is actually is quieter on cold or warm start. The only different I am noticing is the change of engine tone in high RPM range.

stumpjumper

to be honest at high rpm I only hear the air intake, the only change in sound I noticed from oil was at ignition

did you change the air filter at the same time and maybe leave something loose? like the filter cover or the engine cover?

whippets

I'm curious about this too. I have only 41k miles on my 1999 996.
I couldn't find regular Mobil 1 10-W 40 at 2 locations, but they had the high mileage blend. Will it harm the engine in any way?

Thanks,
Brendan

stuttgart1

I had Mobil 1 10w-40 high mileage on my car for 3000+ miles now and it ran fine beside I have to add half quart of oil after 2000mi.

cas951

Haven't used 10w-40 HM so I can't comment.

Personally I'd stay with 10w-40 vs 0w-40. Factory spent many hours during product Development with 10w-40. I can't say that with 0w-40. See your owners manual.

Mark Hubley

Sometimes I think it feels like the engine is running smoother or otherwise differently after I do an oil change or other maintenance. As a scientist, I'm convinced this is the placebo effect in action. Had someone else done the oil change without me knowing, I'm convinced I would have gotten in the car and not noticed a thing.

Perhaps something has changed in your car because of the oil change, but I'm very skeptical. For what it's worth, the second to last time I changed oil on my '99 Boxster I went from Mobil 1 0W-40 to 10W-40 High Mileage, and I didn't notice a thing. I and many others see no reason to fear 10W-40.

JimmyT

M1 10-40 is significantly thicker than 0-40 at most temps lower than operating temp, and slightly thicker at operating temp. SAE grades are defined by ranges, and 0-40 is on the light side of 40 weight. The accepted measure for oil viscosity at defined temps is cST (centistrokes), and the two oils' viscosities are as follows, as provided by Mobil tech data sheets:
____@ 40c @ 100c
0-40 : 78.3 cST 14.0 cST
10-40: 98.16 cST 14.7 cST

As a data point, I've used M1 0-40 in my 4.0 jeep straight six for years (with 7-8K change intervals), but tried the 10-40 high mileage this summer, as it has 145K miles on it. I definitely immediately noticed more valve lifter clatter at idle, which I presume to be from the reduced flow through the hydraulic lifters since the oil is thicker. For vehicles with hydraulic lifters, which includes the porsche m96 and newer, I think using significantly thicker than spec'd oil is a risk.
Jim

JoeFromPA

I'm a new Porsche owner, and I'm not an expert on P-engines, so feel free to take that into account on these comments.

Different oils will change engine sounds and even feel in different engines, and it is not as simple as viscosity grade. Some oils will instantaneously induce noises, or quiet them.

Neither the creation of noise nor the absence of it, due to an oil change, is any indication of a change in engine wear (unbelievable as that may sound). Although, of course, I tend to think less noise is more desirable

My personal take is to assess the engine's normal oil operating temp (which is what for the Boxster? and I'm not talking water temp), your driving patterns, oil change intervals, and ambient environment, and choose an oil based upon those.

Why are people on here using M1 10w40 high mileage? That is a very unusual choice for the typical Porsche, who has seen shorter intervals, less true cold starts, and probably only synthetic based oils.


I'd personally go with (and plan on backing up my words on this) Rotella T 5w40 synthetic or, if my car was kept in a garage above 50 degrees or I was driving it super hard, Mobil One 15w50.

Those are my choices. I'm a big oil fanatic, and have done ~10 oil analyses to date on my own cars. I've run 15w50 in a turbocharged 2.5 liter boxer engine, including down to 40 degree cold starts (Subaru Legacy GT, 2008).

I feel like oil discussions are mostly useless, except in engines with problems where the oil choice can make a big difference.

Anyway, just my .02

eo11

The Owner's manuals for both 2001 and 2003 Carrera 4 clearly specifies Synthetic 10W-40. Both manuals further state "Use only engine oils labelled as API SH or SJ, or ILSAC GF 1 and viscosity grades of SAE 10 W-40 or higher."