Synthetic Oil versus Regular

[mikeleblanc413]

My new to me toad is a 2008 Nissan Versa with 115,000 miles. I recently changed oil for the first time and learned that the high mileage oil I put in was synthetic and not regular as had been used by the previous owner. Give me the pros and cons of continuing to using synthetic and of changing back to regular. THANKS!

[Gjac]

As Vulcanrider said if it does not leak keep using it. My experience is mixed. When I switched to Syn oil in the MH an old 454 with 50,000 miles I had no trouble. I decided why buy 3 different oils so I used the same 10-30 wt oil in the genset and tow car. The tow car 2002 Toyota Corolla leaked at the pan gasket, and I re-tighten it 3 times and 4 oil changes with regular oil before it stopped leaking. The genset, because of less usage did not show up until the following year or so and just got worse. I could not tell where the leak was coming from. I switched back to regular oil and the leak is slowing down but is still leaking. I might try a blend first on an older eng with a lot of miles and look for leaks. I have 104 k miles on the 454 and it runs great with syn. I saw no difference in MPG or any difference in heat reduction using it.

[Vulcan_Rider]

mikeleblanc413 wrote:

What would cause the leak? And, where would it be leaking?

Old engines leak.....and burn oil.

The leaks generally are from leaking gaskets or seals in places like a valve cover gasket because they dry out and shrink with age.

Sometimes the oil burning is because of worn valve guide seals.

IF.....an old engine shows no signs of leaking (oil spots on the garage floor) AND it doesn't "use" much oil between changes, then "high mileage" oil is not needed and actually can accelerate the wear on good valve guide seals.

It's good stuff but not to be used if the things it is supposed to help cure are NOT present. It helps make the last years of a high mileage engine easier to live with but eventually that too stops working and it will leak or belch smoke again.

No reason not to continue with synthetic but shouldn't be using "high mileage" oil unless you really need it.

[cmeade]

Synthetic oil viscosity increases with heat and fossil oil viscosity decreases with heat. I was a crew chief for a race truck team. New engine with 50W racing oil in a 17 qt dry sump system and low oil pressure lite came on at lap 1.5. Panic city with $25K motor. Mobil 1 team in pits next to us gave us 2 cases of Mobil 1. Changed oil and the 2 filters and never saw the warning lite again that day. BTW we finished last and didn't qualify for the main. I run Mobil 1 turbodiesel oil in my cummins, Mobil 1 10W30 in my craftsman riding mower and Mobil 1 15W50 in my 468 cu inch jet boat.

[mikeleblanc413]

Vulcan Rider wrote, "IF the present oil doesn't show any signs of leaking after a couple of thousand miles, keep using it. There are NO downsides to continuing except maybe for a few cents difference in cost."

What would cause the leak? And, where would it be leaking?

Also, THANKS to everyone who has responded. I certainly have food for thought.

[Vulcan_Rider]

mikeleblanc413 wrote:
Give me the pros and cons of continuing to using synthetic and of changing back to regular. THANKS!

IF the present oil doesn't show any signs of leaking after a couple of thousand miles, keep using it. There are NO downsides to continuing except maybe for a few cents difference in cost.

[klutchdust]

1985 K-5 blazer 185,000 miles oil changes every 4k miles no engine issues regular oil
1999 K-5 blazer 287,000 miles oil changes every 4k miles NEVER had the valve covers off regular oil
2008 Jk Jeep 108,ooo miles oil changes every 6500 miles synthetic oil no engine issues.
Now using synthetic in my E-450 Cambria, will be changing every 5K miles.

[3oaks]

wildtoad wrote:
If you change the oil frequently then to me it makes little difference except in how much you want to pay for it. Modern oil wether regular or synthetic is far better than what was available years ago. Follow the manufacturers oil change interval and recommendation.

😉

Plain and simple, straight to the point.

[wildtoad]

If you change the oil frequently then to me it makes little difference except in how much you want to pay for it. Modern oil wether regular or synthetic is far better than what was available years ago. Follow the manufacturers oil change interval and recommendation.

[ugh]

If the manufacture says to use synthetic oil then do that. Otherwise, you have a choice.

[gbopp]

1492 wrote:
Prefer synthetic as it has better flow characteristics in winter, but is also quieter in IMO.

It's interesting you said that. I put synthetic oil in my old Craftsman snow blower a few years ago. It ran quieter with the synthetic, and it's still running great.

[Dutch_12078]

I ran Mobil 1 High Mileage synthetic in our previous Ford 460 powered coach for its superior cam wear characteristics. I'm now running Mobil 1 Extended Performance synthetic in our current Ford Triton V10 powered coach for the extended change intervals and better cold weather starting characteristics.

[1492]

Any threads on oil tends to cause a firestorm. But I only use synthetic in all my cars, and switched to high-mileage Mobil 1 in my mini-van w/100,000+. Prefer synthetic as it has better flow characteristics in winter, but is also quieter in IMO. Don't think it saves any real MPG. And don't notice any leaks, except an occasional drop or two, with no appreciable oil burning other than what is normal with high mileage vehicles.

[KrowNB]

I once read a good analogy about standard vs synthetic oil... imagine your oil as a bunch of steel balls making one surface easily ride along the other. Now think of those balls as being similar but of slightly different sizes (standard oil) whereas another system has all the balls the same size (synth). Makes sense to me... but I'm just an internet reader, not an engineer.

[Trackrig]

You'll probably get as many replies for it as against it. I use it due to extended oil changes and better starting in cold weather. The longer change periods offset the additional cost.

Bill