quirkdiggler

Once you go synthetic oil you are locked in forever... Is this true or Myth? We actually are running synthetic blend but have to get and oil change from someone other than me in a hurry in morning before a trip and will have to pick one or the other, synthetic being $40 or we have a coupon for regular for $10.. Can we go from 1/2 and 1/2 back to reg just once ?

BassAckwards

I think it's the other way around. If you run dyno oil and switch to synthetic the smaller molecules and more lubrous oil will penetrate seals and gaskets and leak.

Not always a for sure thing but a possibility.

Also the synthetic could break up "good" sludge that is blocking leaks on the mating surfaces and gaskets of your engine. That's just what I've read on the subject.

Tones

Myth. there is no danger from switching back and forth except as noted above for high mileage engines.

GraveDigger85

It's a myth. Switching back and forth from conventional to synthetic oil will do you no harm, but i do agree on what was stated before me. The myth that synthetic oil will cause my engine to leak is only due to maintenance neglect over the years or poor quality oil was used to produce sludge build up. Synthetic oil is made with high quality detergents to clean and keep the engine clean in return could loosen up sludge deposits that can cause oil to slip through seals and gaskets that were faulty but just covered up by sludge causing a leak or eventually plugging up your oil pump pick up screen. Besides the costs of oil, I wouldn't see why you would switch back and forth from one oil to another, still with one brand conventional, blend or full.