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THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHMotul 15w40
Leading reported evidence
Replace oil
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
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0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that performed work without a confirmed outcome
1
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Leading evidence: 'Replace oil' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'spec somewhere an engine builder has' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Fill 24 years gives me some confidence in the product' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
I ran Mobil 1 0-40 for 3 years until my mechanic used Motul.
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I run Mobil 1 0W-40 synthetic year round with no issues.
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That combined with the fact that Porsche has used M1 0W-40 as a factory fill for 24 years gives me some confidence in the product.
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I ran Mobil 1 0-40 for 3 years until my mechanic used Motul.
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Suggestion
FWIW I had been running M1 0W-40 for a couple years in FL and all the UOAs looked very good (UOA at every oil change), but I did switch to Motul Xcess 8100 5W-40 on the last oil change after winning 55 quarts of it on Rennlist last year.
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Suggestion
FWIW I had been running M1 0W-40 for a couple years in FL and all the UOAs looked very good (UOA at every oil change), but I did switch to Motul Xcess 8100 5W-40 on the last oil change after winning 55 quarts of it on Rennlist last year.
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Suggestion
It is up to the team when they want to change the fluids, usually depending on how long the race is, but they usually go through practice, qualifying, and the race with the same oil.
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Suggestion
If I acquired a vehicle with a really terrible oil change interval, I�d probably switch to a cheap but quality oil like Mobil 1, drain the oil/filter, drive the car around for 30 mins at temp, and drain and fill again, keeping the filter element, but draining the canister oil.
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Suggestion
FWIW I had been running M1 0W-40 for a couple years in FL and all the UOAs looked very good (UOA at every oil change), but I did switch to Motul Xcess 8100 5W-40 on the last oil change after winning 55 quarts of it on Rennlist last year.
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31 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
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Generation: 20261027T031046Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Metty I replied to your other thread too. 15w-40 is too heavy for cold starts, IMO. YOu won't get oil circulated to the critical parts as quickly with thick oil as you will with thinner. I use Motul 5W-40 and live in the same area. No issues year round.
I don't know about that. I've been considering going to this. I feel the Mobil 1 0W-40 is just to thin for my location (Florida). I am thinking a 5W-40 would be better for me. I've done some research on the oil mentioned, and it is Porsche A40 approved, and on their approved oil list for the 996 engine. Convince me otherwise....
I'll just second the general consensus that a 15W-40 is on the thick side for a 996 at cold start-up, especially on an engine design like the M96/M97 that seems prone to cold start wear (i.e. higher rates of bore scoring in colder climate cars). FWIW I had been running M1 0W-40 for a couple years in FL and all the UOAs looked very good (UOA at every oil change), but I did switch to Motul Xcess 8100 5W-40 on the last oil change after winning 55 quarts of it on Rennlist last year. First UOA won't be for a few months though.
Nope, I agree with you. I ran Mobil 1 0-40 for 3 years until my mechanic used Motul. Mobil 1 0-40 shears down to less than 40 after it accumulates a couple thousand miles. So given your location, you won�t have any issues going to 5-40, and you will gain viscosity on the heat end as well by switching to an oil that doesn�t shear as much as M1.
I made the same switch. But are you sure about the UOA for Mobil 1 looking very good? I�m sure it looked good except for the viscosity Numbers. Did you see those?
Mike, your results may have been different but here is my last Blackstone report. Yes, the final oil change did slightly shear out of spec, but the others were fine - albeit at the lower end of the viscosity range. I have another report from the previous owner at 100k and 104k miles which were also within spec. I totally agree that the general consensus is that Motul XS is a better oil than Mobil 1. I have yet to see any Motul XS8100 5W-40 UOAs from 996s posted just because most people don't use it, but I always post my UOAs on Rennlist every time I change the oil so I will definitely report back in about a month or two with my first Motul UOA.
From my perspective I think Mobil 1 gets a bad wrap sometimes, mainly because its consistently on the lighter end of the viscosity range for what a 40 wt oil should be. But its what the factory race teams use for endurance racing. I've talked with the Mobil 1 tech reps at Petit Le Mans (they always do a tech talk at the Porsche tent) and they swear its the exact same 0W-40 as the factory fill. I've always figured if it could take that kind of beating, it was OK with me.
I also have hypothesized (this is based on nothing more than "internet research" - so take it with a grain of salt), that the main failure modes that kill M96/M97s is more related to poor lubrication at start-up (i.e. bore scoring more prevalent in colder climates, related to fuel enrichment washing down cylinder walls, etc) and has led me to believe that, at least on the M96/M97 engines, there are other properties more critical, like how well the oil flows when cold, additive packages, etc. That combined with the fact that Porsche has used M1 0W-40 as a factory fill for 24 years gives me some confidence in the product. All of that is just conjecture on my part in reading as much as I can find on this stuff.
Anyway - here is my last UOA.
I agree with all of that.
Mobil 1 0-40 is a fine oil indeed, and it tests very well.
But it doesn�t make my pasta taste any better than olive oil. My point is only that oil design and engine design should go hand in hand. And so maybe it�s great for most all Porsche racing engines, but the M96 might benefit from slightly higher viscosity on the high end of the temp spectrum, as well as the low end...
Consider that Hartech suggested that cooling (heat) could also be a contributing factor to bore scoring, in such rare cases where the engine is quite hot, and the oil could approach 250F or more near the piston/cylinder, and the 40w label ends up being something into the 30s or even less.
Is there enough viscosity and protection to prevent the piston from touching the cylinder wall in this case?
If we are talking track use, we want an oil that can make it happen - retain viscosity - and doesn�t aerate as well.
So for Mobil 1 fans, perhaps hot summer climates, a Mobil 1 50w would be better, and for winter climates, I�d rather have 0-40 all day long to protect against cold start wear.
Edit: Hartech reference:
https://www.hartech.org/images/downl...0(interim).pdf
The first thing you have to allow for when you compare running M1 in a
race car vs your street car,, in Le'man racing the competitive cars seldom
do more than 2 events on their engines,, many do 1.
They run thin oil to let the engine spin easier,, protection is kinda secondary to HP..
They also dump the oil between each segment..
Also I've spent enough time at the tracks and worked with name teams,,
seldom, does the car have the oil in it that the stickers say they do.. YMMV..
Look at the oil weights Roush recommends for their engine rental program..
They have it sorted by track.. and Class.
They can also run M1 and since they are inside track they can get additive packages (
That they don't even know the full content on) And may not be available to the public for road use..
Cheers
I would respectfully disagree on one item. They definitely do not dump oil between each segment, at least not in IMSA endurance racing - perhaps other series. I've worked as a Pit Marshall for the Daytona 24 and 12 Hours of Sebring for many years, recording all the maintenance done to during pit stops as well as driver changes. They will top off oil if its low. There might be an oil change if the car goes behind the wall, but not in the course of routine pit stops, driver changes, etc.
As far as what oil is actually in the factory 911/912 cars, I was only relaying what the Mobil rep tells us in their tech talks at the races - which is that it is the same stuff as the factory fill. Maybe they are just blowing smoke. Maybe they are only reporting part of the story. Again, this is just for the Porsche factory 911/912 that run in IMSA GTLM. There could be countless custom formulations being used by privateer teams. It would be interesting to see a UOA on the oil that comes out of those cars.
I'm not trying to be an M1 cheerleader. Just that my own UOAs over 30k miles on an engine that now has over 130k miles miles have shown satisfactory characteristics. I realize that is purely anecdotal and far from a scientific study.
Mike - I'd love to see some UOAs after your switch to Motul 5W-40 if you've got them. They seem to be few and far between on M96s based on some Google searches.
I didn't mean each race segment,, sorry could have said that better.. I meant between testing/practice/qualifying and the races..
My experience is based on our races out west,, never had the time to go back to the big ones..
I built a system a couple years ago with dry breaks that could do a 2.5 gallon dry sump in 20 seconds. We planned on using if the engine started eating itself.. Luckily it was not needed.. We would have had to push to the cold pits then back. Woulda been ugly..
While I don't have any results from racing with X-cess 5W40, I've attached a UOA from Motul 300V 0W40 drained from the Pfaff Porsche 911 GTD car after the Rolex 24 this year. The oil was changed the night before the race.
It is up to the team when they want to change the fluids, usually depending on how long the race is, but they usually go through practice, qualifying, and the race with the same oil.
Yes, that is the correct moly count. There are a few VOA analysis numbers online to compare
how the oil typically looks before wear
. We will also share a gear oil test from Sebring in a couple of weeks and will share it with the Rennlist community
and editors
.
I don�t think so. If I acquired a vehicle with a really terrible oil change interval, I�d probably switch to a cheap but quality oil like Mobil 1, drain the oil/filter, drive the car around for 30 mins at temp, and drain and fill again, keeping the filter element, but draining the canister oil.
But if you are talking about swapping good oil for good oil, any residual oil left in the system is probably just fine, even if brands and viscosities are quite different.
I don't have valid data. I would estimate less than 0.1 quart. A lot has to do with how long the drain plug is left open. I know when I drop the sump plate, there's probably only a couple of ounces there. Where else will it pool in significant quantity?
Just did my oil/filter change. Left the drain plug out overnight, then lifted the left rear this morning and bunch more oil came out. That is because the bottom part of the oil pan collects a pool and the oil doesn't make to the drain hole unless the car is slightly tilted on the left side. You've seen the design of the oil pan, the large circular indentation in the oil pan just to the left of the drain plug.
Not that it matters, but I went from Mobil 1 0w-40 to Liqui-Moly 5w-40 Leichtlauf High Tech.
Yes - that little depression will hold the most oil of any area in the engine, from what I can tell. There is a little channel from it to the plug opening, but the depression is still lower. Tilting the car, or dropping the pan are about the only ways to get more out.
Not sure, I�m guessing as well. Maybe oil cooler, valve covers and their associated pumps, and that�s about it. I�m conflating with the air-cooled cars and the oil lines and coolers that run to the front of the car.
There is probably a spec somewhere an engine builder has, but then again, an engine builder doesn�t assemble these engines dry, lol.
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