Originally Posted by chadg2
Does anyone know how I could e-mail Chrysler Engineers to ask them why they recommend this liquid gold engine oil in the 3.0L Ecodiesel engines. Diesel engines have been running millions and millions of miles with a good high quality 15W40 in them almost forever. The new Ford and Chevy Diesels with the same emissions standards as the Jeep/Ram are still using a high quality 15W40 engine oil. I would not have such a problem using a full synthetic engine oil, if they could give me proof as to why it's better than a good quality regular engine oil that these big rigs are running down the highways. I would rather change a non-synthetic engine oil at 3000-5000mi, than keep a synthetic in for 7500 or 10000mi. If you get any dirt in the engine, it can't get out till you change the oil. I've used Mobil Delvac 15W40 in my 5.9L Cummins from 2006 to 2009 and took a oil sample at 5000 miles and it still had many miles to go with great #'s. I changed the oil and that's the mileage I changed at every 5K. Never burnt a drop of oil and ran like a champ the entire time I owned it. My question is how could 15W40 hurt these ecodiesel engines? It's much cheaper than the liquid gold they ask us to use, and available everywhere instead of almost nowhere. Has anyone else used anything but the recommended 5W30 full synthetic in these engines? Thanks.
Im pretty sure Chev require DEXOS certified oil which is 5w30. Not sure if its synthetic, but I bet you it is. All the new diesels need this due to the DPF. Your old Cummins wont have a DPF.
What happens is the DPF fills with soot, and requires high temperatures to burn it off. Its called "regeneration". When the DPF requires a regen, the ECU injects diesel during the exhaust stroke, so basically the diesel goes straight out the exhaust port and burns up in the manifold to increase the temperature which is required for the regeneration. When this all happens, its possible for some of the diesel to find its way past the piston rings and mixing with your oil. This would contaminate and break down a standard oil. This is why you need a certain oil type, usually synthetic, as it resists breakdown by diesel contamination.