On another car forum there was a thread started about spun rod bearings. The motors in question are modified and built/tuned Turbocharged 2.4L's in the Neon SRT4. Most were in the 350-420hp/400+tq. After a bunch of people were trying to figure out what caused the problems, I decided to ask the question, "what oil were you using?" The 1st two responses were "Mobil 1 5w30". I for one wouldnt use M1 5w30 in a 400+hp 4 cylinder motor, but that is just my preferrence. I try to choose ACEA A3/B3 API SL/SM motor oils in my mostly stock 2.4l. Was I wrong to tell them that M1 5w30 isnt the right choice for these high HP/TQ motors? I tried explaining the HT/HS ratings and showed them the break down of the different ACEA specs, but they continued to tell me that the oil had nothing to do with their spun bearings. I also got the, "well, my 500hp cobra did just fine on M1 5w30 back in the day", "oil had nothing to do with it" answers. I tried telling them at a minimum, they should be using an ACEA A3/B3 with an HT/HS of 3.5 or higher. I then recommended M1 0w40-5w40, T6 5w40, M1 high mileage 10w30/10w40, Redline 5w30-10w40, and GC 0w30. Am I right to think that the M1 5w30 wasnt up to the task of the extremely high pressures and probably caused the spun bearings? Another note: their data logging showed nothing out of the ordinary when the spun bearings accured. Tunes were in check.