I too love oil threads.

Let's put it this way: My Jeep has 167k miles on it. I always ran a conventional or synthetic blend (usually 4x4 synth blend). This most recent change, I took out conventional Pennzoil 10w30 (the worst oil I've ever used in it) and replaced it with Mobil-1 5w30. So far, it's been the best oil I've ever put in it.

The ticking is almost completely gone from the engine (except when stone cold on sub-25°F days). Also, I was getting 14.5-15MPG with the conventional. Without changing my driving conditions at all (cruise at the same speed) I am now getting 15.5-17MPG. My last tank claims 18.0MPG according to my receipt, but I think I may have missed a possible gallon at fill up. That would still put me at 16.67 though...

I never thought it would make such a difference in such an old engine that doesn't even have overhead cams. I was wrong.

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Back in the saddle - 1972 280SE 4.5