Anyone switched to synthetic and wish they hadn't?

There was a TSB stating that you can run a 5w-20 oil in these engines. I have seen a guy doing just that with a UOA, everything was looking good.

 

I've used M1 in the recommended flavor, changed at 5000 mi, in the last 8 vehicles I've owned. Have never had a reason to question doing so, so will continue to do so. Empirical evidence only.

 

if you have any leak at all, synthetic could make it leak more

My 92 VMAX leaked more (micro valve cover gasket cracks) and burned more oil, change to dino and no more burning.

 

Using synthetic is a no brainer. Mobil 1 has a rebate every year if you buy a 5qt jug. Ends up costing you ~$12 after rebate. With that being said, why would you go with conventional oil for that price.

I end up buying 2 jugs and a quart at the same time, send the rebates in, and I'm all set for a year with oil.

 

It took me a little while to find the usable power band in this truck. It is slow off the line and if you let the it get under 4,ooo it takes a second to recover, but keep it 4,500 to 6,000 when you want to get going and it does all right.

 

Just the opposite with a 2004 JGC with 4.0 I6(known leaker).Not sure what was run in it in the past,but I put in Valvoline Maxlife synthetic and the drips slowed way down.Motor also runs quieter.And that was about 5K miles ago.