Tier1Terrier

I live in South FL so my car is never in a very cold climate. I don’t track my vehicle (at least at the moment) but I generally enjoy driving hard on the engine whenever it’s safe - so my car spends a lot of time in the higher rpm range. My 991.2 C2S currently has under 10k miles and I will be doing an oil change soon. I’ve read a lot of threads recommending the use of 5W-40 instead of 0W-40 in warmer climates. This raises a lot of questions in my mind as I feel that messing with manufacturer recommended oil requirements can be problematic.

1. What if any performance improvements will be noticed. What are the long term benefits of using 5W-40 instead of 0W-40 in a vehicle driven in warmer climates.
2. Does using a different oil than what’s recommended affect the warranty on the engine. I have a Fidelity Platinum plan which includes powertrain.
3. Are there any potential downsides to switching from 0W-40 to 5W-40?
4. Are there any issues with switching back and forth between 0W & 5W. So for example, using 0W in Winter & 5W in Summer? Or does switching back and forth potentially introduce other issues?

LexVan

1) None (won't effect, braking, acceleration, or handling)
2) No. There are 100s of Porsche A40 approved oils. There are 3 approved viscosities; 0W40, 5W40, and 5W50
3) None
4) None. And remember, 5W40 and 5W50 are good till -13 degrees F. Wen are you every going to see those low temps. Never!

991.1 Guy

I agree 100% Some things we don't need to overthink.

Tier1Terrier

Thanks @LexVan My first question should have been asked differently. I was thinking more about the performance of the oil in terms of its intended use (lubricating engine / reducing wear on engine components). I’ve updated OP.

Wolpertinger

I switched from Mobil 1 0w40 to Liqui Moly 5W40 Leichtlauf for the last 2 oil changes and I've been very happy with it. I swear the engine sounds smoother, but that's probably in my head. I live on Vancouver Island, so think Seattle for weather and temperatures. I did a used oil analysis on my last oil change and all was very good.

desmotesta

I am disappointed that this did not turn out to be a typical Oil discussion thread


Kidding aside.. that goodness that there is consensus on what has been available information for a long time

Carl Over

I switched from M1 0W40 to LiquiMoly 0W40 and would say that engine is not quieter on startup. Maybe a little ticky, clacky initially. I’ll do 1 more change and UOA with the same and decide. Might go to M1 5W50.

biggreek

Now, engines with tight tolerances are particular on oil viscosity. We aren't dealing with a small block chevy where the clearance for the rods are the grand canyon.

Once you switch to a thicker viscosity, the engine "compensates" for the thicker oil. Clearances become larger. Going to a thinner viscosity, there's a greater chance of limiting the engines life down the road. You'll burn more oil, there'll be less oil pressure, etc... Now, will you notice a difference between 0w and 5w? Probably not, but I won't take that risk, personally.

Mojo.K

I live in San Diego, and I did switched to 5w40 at my last oil change. On startup, the car does crank a tiny bit more when car starts up using the higher viscosity when car has not been started up for a 2-3 days compared to 0w40.

737gdog

Why 5w40 vs. 5w50? I am sticking with 0w40 until out of warranty as my local dealers will not use 5w50 and I have zero confidence they will support a warranty claim on my behalf if I use 5w50 as it is not listed in my ‘19T owner’s manual. Seeing as how I only put about 3k miles annually on the car maybe I should just go with an indy, do it myself, and use 5w50....

Mojo.K

Sorry I meant to say 5w50

Bxstr

This is an interesting point and one I had not thought of. My plan was to switch to 5W50 in the spring, but this has me thinking twice given that my car has run 0W40 the majority of it's life.

Carreralicious

FWIW, Mobil 1 5W-50 is a Porsche A40 approved oil, so I don’t see how it could be a problem to run it.

Kelsey

Could you please post your oil analysis results? That would be greatly appreciated. Thanks

Kitc2246

How does an engine "compensate" for a higher viscosity oil? Are you implying the engine will have significant wear? No ones talking about using 90W for the engine, just moving up from 0W40 to 5W40 or 5W50, which for most Porsche's are an approved viscosity. Today's engines have better metals and are built with tighter tolerances to use low viscosity oil primarily for MPG purposes. You should use the viscosity oil that the manufacturer recommends. Mobil 1 5W50 is recommended for many Porsche models operating in high temperature areas and extreme temperature use like tracking.