patrick.net

This is a topic shrouded in mystique. Try the Bob is the Oil Guy forum. You can spend a lifetime reading more than you ever wanted to know.

I would have no issue using synthetic in a modern motor that hasn't been run high miles with dino oil. Not sure about in an old motor that always ran dino (will clean out the worn seals and possibly cause leaking).

Did my research. I've been using SuperTech full synthetic at Walmart for a few years.
No problems & cheaper.

www.youtube.com/embed/o5pSlL87IoY

When I bought my Camry hybrid the dealer said synthetic only with this engine. I don't know why.

If it doesn't need synthetic you might be wasting your money. Just make sure it's the right grade, that's the most important factor.

Non-synthetic is still pretty damned tough. I'd only bother if the owner's manual says "DO IT," or if you have a turbocharger, or a high-compression engine which requires 87 octane or above.

I think it's basically mandatory if you have a turbocharger.

They should stop calling non-synthetic oil "dino" oil: it comes from dead plankton and algae.

There is no shortage of high dollar synthetics and oil additives out there.

Most engines don't require these and it is more important that you change the oil at regular intervals with conventional motor oil of the appropriate spec called out by the owner's manual.

It's similar to the octane debate. If you own a low compression economy car, chances are that you'll see absolutely no benefit to paying more for 89 or 91 octane when the engine is designed for 87. Consult your owner's manual.

You also said that you tend to keep cars a long time, 200k miles... Is that because you've always used synthetics up to now? Of course not. So don't start now unless your particular engine calls for it.

If your cars maintenance schedule is based on synthetic, and you have a warranty, use synthetic. Probably the dealer is using whatever the manufacturer recommends, and that would be fine. But read the manual.
I drive higher mileage cars and only put a few thousand miles on in a year. In that situation, synthetic is a waste. You have to change oil every few months anyway, and never get the miles in. Synthetic is supposed to provide higher fuel economy as well as longer change intervals fit people who drive a lot. Literally, your mileage may vary.

BayArea says

Most engines don't require these and it is more important that you change the oil at regular intervals with conventional motor oil of the appropriate spec called out by the owner's manual.

Pure FUD. The only way to determine if the oil needs to be changed is by pulling a sample and analyzing it. Most people won't go that far and just change the oil well before the oil has broken down or been depleted of the additives.

If you really wanted to run an engine for a long time and avoid engine wear, you really need a bypass filter that can filter out the sub-micron particles and keep the added chemicals in spec. Oil becomes depleted of the additives long before the actual breaks down. The only way to know if the chemicals are depleted is to analyze the oil. Car companies just pick a mileage number that will cover most driving habits. Why do you think Subaru went from a 7.5k interval to a 6k interval the next year?

I put about 700 miles on my car a week (2010 Subaru Impreza) but I have extended the oil change interval to 10k by using Mobil 1's top grade synthetic and Mobil 1 filter. The only problem with doing this is that extending out the oil changes and letting the sump get depleted from normal oil loss past the piston rings usually does not end well. One of the only negatives about the flat 4 is that it burns oil faster than any other engine design that I have owned. I have to add a quart every 3 k miles to keep the sump at the high mark.

The real basis for the short interval changes are normal oil losses (people too lazy or stupid to check the oil level at the gas station) or the additives are out of spec low.

Use synthetic for turbo motors and when the manual tells you to. Buy the 5 quart container of Mobil 1 for $25 at Walmart.

just any guy says

Buy the 5 quart container of Mobil 1 for $25 at Walmart.

I could not agree more! I would add that changing the oil yourself is also a good idea. I doubt even the factory trained techs at the dealerships follow the manuals. Buy a Craftsman torque wrench, the Toyota oil filter tool, and single use crush gaskets (if the car uses it) and you can get the change time down to 10 minutes of actual work. The old oil can be put in the oil canister that you the new oil came in and turned in to recycle.

I will add that of all the heads that I have pulled off an engine, the engines that used synthetic oils always seemed to have the original holning marks still visible in the cylinders. Synthetic is far superior to conventional oils and the tests consistently show this.

If you live someplace where it gets cold, having synthetic oil makes cold starts on winter mornings a little easier.