Thread: Synthetic Oil

If it has about 100k or less, I say run fully synthetic. I've been using Mobil 1 for years, but thinking of switching to Penzoil fully synthetic cause Mobil is a dirty oil. I've found if the engine hasn't been maintained or has high miles and has always had conventional oil run in it, changing it to synthetic may actually damage it. And if you were running synthetic and switch back to conventional, it may ruin the motor. Happened with my neighbor cause his buddy didn't tell him he ran synthetic.

Originally Posted by matt5112

Those are myths.

You know you can quite literally buy two quarts of synthetic and two quarts of conventional, mix them and run them with no issues?

You can also mix weights.

^^^^^this I have done atleast half a dosen times

Originally Posted by matt5112

Those are myths.

You know you can quite literally buy two quarts of synthetic and two quarts of conventional, mix them and run them with no issues?

You can also mix weights.

I've seen on the oil company sites about the ability to run synthetic on higher mileage cars. They also claim the ethanol in gasoline isn't bad, but I've seen plenty of destroyed marine engines especially. But for the synthetic, I've noticed a lot more oil seepage at the seals on higher mileage engines and I have a Honda F22b2 engine sitting in my scrap pile that burned up the connecting rod bearings soon after switching to Mobil 1. It had about 150k on it. Also, if you have higher mileage on the engine, what's the point of switching to the more expensive fully synthetic. Keep using the oil you've used to get there, which I'd recommend Penzoil conventional oil. For a new engine though after it's been broken in, I absolutely recommend the fully synthetic.

I switched over to synthetic at 100k. The only problem is i think my valve cover leaked ONCE. I cant even prove that it was the oil because it happened 9 months and 5k miles later. It is also a very common problem (there was actually a recall for it.) I would still recommend it. If you get a good, long life filter I've heard you can go 7k or more between oil changes if you are comfortable with it. I reaserched it a lot also and I agree 100% with matt5112.