- Nov 17, 2016
- Middle Florida
I have a 1999 Porsche 911 C2 Cab 3.4. I have recently ditched the non-FS Mobil 1 0w-40 which was in the crankcase for Castrol EDGE 0w-40 (which is already smoother and offering slightly higher idle oil pressure at operating temp). However, I am seeing that the KV100 of these 0w-40 oils seems to be creeping lower. I tried some Pennzoil Plat Euro 0w-40, which simply did not run as smoothly in my engine. I'm satisfied with the Castrol 0w-40 so far, but am curious regarding a thicker solution. According to various Porsche engine-building experts on the subject of the M96 flat six engine (1999-2005 Porsche 996 engines, from 3.4-3.6 liters), moving to a 5w-40 for the additional KV100/HTHS viscosity offers notable improvements in chamber wall and valvetrain wear. Jake Raby (Flat 6 Innovations) recommends Joe Gibbs DT40 (though it is not Porsche A40 certified, it was claimed to be developed with the M96 engine as a primary factor) over other offerings due to higher ZDDP content and higher overall KV100 viscosity. He doesn't rec anything else now, and forces people who use his IMS bearing solutions to use that oil in order to keep their warranty for his work. When Jake Raby was asked about using an HDEO (Rotella T6 5w-40, in this specific case), he mentioned that oil foaming/aeration was a serious issue that Rotella T6 did not address...and he offered anecdotal observations where he had seen a foam "head" (like the head of a freshly poured pint of beer) form in a several engines running T6 on track days, and that this would lead to the obvious oil starvation issues that performance engines are susceptible to in these circumstances. However, I have read from several sources that Chevron Delo 400 LE/XSP (CJ/4 & CK/4, respectively) 5w-40 has a superior anti-foam additive package that was specifically designed to address oil foaming/aeration in the Ford Powerstroke series of engines (both current PowerStroke and Navistar engines) for their high pressure fuel injectors and pumps. The PDS even mentions the "defoaming additive [which] helps prevent air entrapment". I'm not too terribly concerned with Cat life for my 99 911, though the cats do tend to run on the hot side and upgrading to 200 cell cats (OEM are 100 cell) is a common performance upgrade. Delo 400 5w-40 is SN rated and stated to be suitable for mixed fleets, as well. I would be very excited to have inexpensive access to a solid 5w-40 oil that costs only slightly more than the $22 5 quart Castrol EDGE 0w-40 I can get at Walmart. Oil change intervals are very short; 3k or 6 months until engine gets cleaned out. Won't be exceeding 5k/6 months with any oil...ever. Yes, I know it's a waste. I have already installed the LN Engineering oil filter adapter and am running a Fram Ultra 3675. The info I can find on the current EDGE 0w-40 is KV100 @ 13.1-13.6 and an HTHS of 3.6-3.7. I can't find any HTHS figures for the Delo 400 5w-40, but KV100 is rated at 14.6. I've read that going above KV100 of 15 can result in Variable Valve Timing errors, so I'm not interested in exploring that. I live in Central Florida. This is a 2nd vehicle for me, and I do not short-trip it. However, when I do get out and drive, I drive HARD once it is up to operating temp. No abuse, but it's not uncommon for me to bomb on back roads for an hour, then hop on a highway and hammer-down until I hot traffic or get off...and then bake in traffic at a few stop lights until I get to my destination.....in the 95 degree heat and humidity. I regularly explore RPMs from 6800-7200. I have a low temp thermostat installed, the vehicle is in excellent condition, and all temps and indicators are normal. I just want the higher viscosity in the heat without triggering error codes for the VarioCam (VVT) system without being forced to purchase some boutique oil at above-amsoil prices. Can anybody offer any information, insight, commentary, etc on how much oil foaming could be an issue for an HDEO oil such as the Chevron Delo 400 5w-40 in my high-revving (7250 RPM redline) 3.4 911 engine?