Originally Posted by doclouie

If you really are not concerned with cost use Driven DT-40 oil. It already has Moly in it. One of the best oils for a 997.1.

Originally Posted by Fullyield

Charles, what are your thoughts on using ZDDP oil additives such as ZDDP Plus or Rev X ZDDP?

Originally Posted by Fullyield

Check out at LM Molygen 5W-40. It already has the moly blended so neither MOS2 or Ceratec need be added....per LM.

Originally Posted by DesmoSD

I've been using Motul Xcess 5W-40 and planning to switch to Driven DT-40. If I recall, it's advised to use the BR30 oil for about 100 miles before switching to DT-40. Is that correct @Petza914 or @Charles Navarro ?

Originally Posted by Charles Navarro

Flush is not required when switching to Driven. I'll clarify flush refers to running another Driven oil for a short period to drain out before going to DT40, not using an oil flush product sold to "clean" your engine. You shouldn't run these products in your Porsche engine.

The thought process behind doing an intermediate oil change when switching brands is to minimize the effect of cross-pollination of additives that will throw off a used oil analysis. If you don't care about the UOA results for that first oil change, then there is no need to go through this process or just be aware the first UOA won't be best indicator of how the oil is performing.

Originally Posted by jedrs4

Great to hear from the experts. I'm moving back to the DT40 camp now. The price isn't a concern and I do like the best for engine health. Now I understand the flushig process better. I won't measure the first 2 oil changes which I'm doing a 4k interval. I'm at 3600 now and ready to make an order. Anyone have recommendations where to get a fresh batch of DT40? I see links to driven, LN and summit. I doubt Amazon is the way to go.

Originally Posted by Charles Navarro

You could run BR40 or HR5 as the flush oil, if you so choose. But like I mentioned earlier, you're not going to hurt your engine if you skip this step.

Originally Posted by DesmoSD

@Petza914 Brought up a good point to use the BR oil for 100 miles before switching to DT to reduce any cross contamination between UOA results. I'm in CA, why do you recommend BR40 over BR30?

Originally Posted by Charles Navarro

BR40 is a 10w40 which would be the proper viscosity. BR30 would be too thin, especially in a warmer climate like CA.

Originally Posted by Prairiedawg

Is there any reason why Ceratec cannot or shouldn't be mixed with M1 5w50? Any reason not to use it with an engine with under 20k miles?

Originally Posted by Charles Navarro

Stay clear of them. That has been my opinion on them for the last 15 years :-) If you use a good oil, no need for additives. Again, using them is tantamount to using your engine for a science experiment.

Originally Posted by jedrs4

Great to hear from the experts. I'm moving back to the DT40 camp now. The price isn't a concern and I do like the best for engine health. Now I understand the flushig process better. I won't measure the first 2 oil changes which I'm doing a 4k interval. I'm at 3600 now and ready to make an order. Anyone have recommendations where to get a fresh batch of DT40? I see links to driven, LN and summit. I doubt Amazon is the way to go.

Originally Posted by CAVU

I was using Ceratec in three of my vehicle using Mobil 1 5W-50 FS X2. UOLs for all of them. Positive results.

Past UOL Molybdenum results (ppm) Most recent first:
- Mobil 1 5w-50 309 and 309 (Ceratec added per recommended volume)
- Motul 8100 Excess 5w-40 4 and 17 (no Ceratec)
- Mobil 1 0w-40 87 (no Ceratec)

Yesterday, one of the 3, received engine oil flush treatment and an overnight drain. Sticky cam shaft adjuster and I "hope" the oil flush addresses the problem. Switched to Driven DI 0w-40 for the primary reason of running an oil formulated to reduce LSPI. LN Engineering has decent case prices.

Originally Posted by Sporty

Wow this turned into an oil thread, didn't mean for that to happen, but it's ok as it is ultimately related.

So, as far as DT40 goes, how long / many miles before it affects your catalytic converter, if at all. IIRC that is the reason why it was not an approved oil according to one of the earlier posts.