Moble 1 5W30 Synthetic on my engine with 146K miles. It does consume some oil, and a little smoke here and there. When it gets too bad, that means it's worn out, and I'll rebuild when that time comes. I also run the FMS Oil Cooler, makes a big difference in oil temps.
Don't forget the first number is it's cold viscostity, the second number after the W is it's hot viscostity. 5W30, 5W40, 5W50 are the same when cold, but they thin out differently as they heat up. It's those cold starts, or what we should say is dry starts where the oil is in the pan, and the upper parts are near dry, which is stressfull on the engine. A thicker oil will take longer to reach those parts. Dino oils tend to loose thier lubercation qualities when they get hot, so running a thick dino oil might be a good idea. Synthetics tend keep thier characteristics better and penetrate better due to thier molecular level being smaller, but this also leads to leaks. Well, leaks you need to fix anyways.
I'm not saying running a thicker or thinner oil is better, they both have thier pro's and con's like anything else.
Don't forget the first number is it's cold viscostity, the second number after the W is it's hot viscostity. 5W30, 5W40, 5W50 are the same when cold, but they thin out differently as they heat up. It's those cold starts, or what we should say is dry starts where the oil is in the pan, and the upper parts are near dry, which is stressfull on the engine. A thicker oil will take longer to reach those parts. Dino oils tend to loose thier lubercation qualities when they get hot, so running a thick dino oil might be a good idea. Synthetics tend keep thier characteristics better and penetrate better due to thier molecular level being smaller, but this also leads to leaks. Well, leaks you need to fix anyways.
I'm not saying running a thicker or thinner oil is better, they both have thier pro's and con's like anything else.