I've heard many say that about the noise in Mobil 1's in Jeeps and other vehicles, but I think that is all in people's heads. I've had plenty of Jeeps and the only time I ever heard more noise with Mobil 1 was when using Mobil 1 filters on my 3.8. For some reason the anti-drainback valves leaked at the particular filter angle in that engine and you'd get cold start rattle. So I switched at the time to Motorcraft and then later to Fram. Problem solved. Otherwise, the engines run as smooth as on anything else. That includes Jeep 2.5, 4.7, 3.8, 3.6 and 2.4 engines.There's nothing especially cold about South Bend compared to any other Northern state. My Aunt and Uncle lived there for a while and we'd visit at different times of the year. The difference for you is that you're not used to it.
Historically, Mobil 1 products bring out some noise in AMC/Jeep 2.5L, 4.0L, and 258's. There was talk all over the Jeep forums and even here about it before the JK / JL days.
Chevron 5W30 was on sale at Walmart for $8 +/- a jug. It's a syn blend and it's going into my Wrangler's 2.5L very soon. It would work well in your Renix motor for South Bend winters.
Spot on KC, thanks for bringing that up. Forgot to mention the "Jeep 4.0 hates M1" earlier.Mobil makes fantastic oil but Mobil 1 and the Jeep in line 6 don't historically do well together. Countless UOA's with Jeep 4.0's and 5x the iron numbers of any other oil. People will correctly say you can't judge wear by a 20 dollar UOA, but since no other oil does this and Mobil does it over and over again its pretty simple just not to use Mobil in that engine.
While your temps are not especially cold, they are plenty cold enough and the Jeep 4.0 can be a little cranky when the temps dip. It's also an engine that does better on slightly thicker oils, so in my world the perfect solution for you is a good Euro 0w30, 5w30/40 or 0w40.
Castrol 0w30 or 0w40 (lots of PAO base) and a bit more ZDDP for your flat tappets would be great choices.
How would you handle that? Are Optimas good for extreme cold? I've been seeing mixed reviews lately. People are upset at how they moved the plant to Mexico, and some are saying the quality dropped. I don't know of any primo batteries other than Optima.I'd be worried more about the battery.
The poster needs to live in Interior Alaska for a winter, or actually work and drive the Dalton Highway way above the Arctic Circle a winter or three! In these areas, -20 degs F is a quite NORMAL daily temperature, and -35 and -45 degs F temps are not uncommon.Someone needs to drive up to Edmonton, Alberta. Cold in Indiana? 5w30 is just fine. Welcome to Bitog.