Synthetic oil reviews

I am trying to find a independant review of synthetic oil. No Amsoil commercials please!!!

I want to switch my Scion XB over to a Full synthetic.

Just about any brand name synthetic that has API ratings will give you all the benefits of switching from non synth . No miracles there though .

Yep, no need for a review, they’re pretty interchangeable. If you want to do this, Mobil1 is typically available for a good price by the jug at Walmart. Why do you want to change?

I want to extend my oil change intervals

I wouldn’t do that, even with synthetic oil.

I want to extend my oil change intervals

What year is your Scion XB, and is it still under warranty? If so, ask the dealer if they will still honor the warranty if you go beyond the oil change schedule documented in your owner’s manual.

I want to extend my oil change intervals

I feel it’s OK to extend oil change intervals using synthetic oils. There’s really no reason to use them unless you can. Regular oils are good and cheap enough for normal change intervals. But, if you use a car in high mileage situation, where combustion by products are not likely to accumulate as much and you do it to compensate for oil break down, then yes. If you’re an average miler of 15k to 20k per year but do mostly highway, yes. Stop and goer with frequent engine shut offs like many people do with fewer than average miles per year, than no.

Under ideal, high mileage, heavy highway use, 7500 to 10K mileage intervals are used regularly, and successfully by many agencies. We guys who drool over used police CV as used cars understand the less frequent but successful (10K around here), oil change intervals they have. Your tax dollar and pocket book would want it no other way. I know retired cops who do it now with their own vehicles. They’re converts.

It’s foolish and a waste of good money, to use synthetics and change oil too frequently (as with any oil type), except in very specific high load circumstances, or very cold weather applications. Frequent oil changes (3K or less) are often way over rated.

Bottom line; how you use your car will help determine whether it’s a good idea.

My own perspective on using synthetic to extend oil change intervals is that doing so is not a good idea. While I respect that synthetics survive extreme heat better, such as that caused by turbochargers, synthetics are just as susceptable to particulate contamination and to dilution and contamination from combustion blowby as dino oils are. All engines have minute amounts of blowby, even new ones.

In short, synthetics are subjected to contamination just as dino oils are. If your owner’s manual recommends synthetics, then by all means use them. But if it does not, I remain unconvinced that under normal operating conditions it’s superior.

I also remain unconvinced that it should be used to extend oil change intervals. One of the oil’s many tasks is to wash down the cylinder walls, leaving a residue to lube the cylinders after the oil rings wipe them down. I believe that washes with oil carrying 5,000 miles worth of contamination are still better than washes with oil carrying 10,000 miles worth of contamination.

And now, my disclaimer. I have no data to back me up. I’ve yet to find any comprehensive studies that look at the long term effects of synthetic with extended oil change intervals versus dino oil with manufacturer-recommended oil change intervals. If any such study exists, I’d truely be interested in seeing it. Everything I’ve ever seen only compares performance of dino against sythetic in controlled lab experiments that may or may not represent real world use. And the lab experiments were all done in the name of selling synthetic.

The math is really against you. Synthetics cost 3-4 times the price of normal dino oil and the most you would be able to safely extend the drain interval is 25-50%!!! If your car is under warranty, you cannot extend the interval at all without voiding it.

This is the 21st or so post on that specific subject, I believe, and the best way to get maximum engine life at the LOWEST OVERALL COST is:

  1. Use normal oil recommended for the engine.

  2. Change oil and filter at the recommended interval for highway driving in normal weather.

  3. For stop and go, and severe operation, drain oil every 3000-5000 miles.

If you do the above, your cost will be less than 1/2 of using synthetic and the engine will outlast the rest of the car!!!

P.S. This is all the review you need!

THIS is where you go to obsess about Motor Oil…

If you shop at walmart they’ll cost you about 30-40% more, not 3-4 times as much. If it costs you that much you’re being ripped off. Walmart carries a lot of synthetics in 5 quarts jugs for a little over $20, their prices for the same size jugs of conventional are about $12-14

Sorry, I don’t shop at Walmart and do most of my own oil changes. Even at Walmart, the economics still don’t make sense, since I don’t recommend extending the drain interval.

One of our cars is used for short trip driving in severe weather, and I put Mobil 1 one in it in the winter, not to save money, but enjoy quick starts and less engine wear. It get dumped at 4000 miles just the same.

And, lest we forget, for the average non involved consumer, regular oil change intervals, at least gets some one of some knowledge under the hood regularly, to check and top off other fluid levels, tire pressure etc if car is placed on a jack. With an extended oil change, which I believe in, someone should be checking things on a regular interval shorter than those changes. Gee, I remember in the military, it was every morning. How things have changed.
Lets move to EVs and end this foolishness.

Right; the contamination factor is the same, and the additive package is in there to counteract these contaminants.

The main advantage of synthetics is then to be more resistant to COKING, THINNING OUT at very high temperatures, and FLOW BETTER at very low temperatures. Those qualities reduce the metal wear particles, so we have a slight advantage there. Most oil contaminants are not metal wear particles.

European synthetics have a very much increased additive package, even more that the “long drain” Mobil 1. Such oils can indeed go longer, but are not available for $20 a 5 quart jug at Walmart.

Excellent points. I check everything at least weekly, but many only pop the hood when they do the oil change. Some of them post wondering why their oil ran dry and their engine seized.

I like EVs too. Especially the Teslas.

Think how much development could have taken place on installation of charging capabilities at highway gas stations to create an infrastructure with the $3Billion that was wasted on Cash For Clunkers. What a waste that was.

No argument here. But I remain unconvinced that better performance at extreme temperatures makes extending oil change intervals a good idea. Those very extremes make the operating conditions severe anyway, and changing more often under severe conditions is always a good idea.

I am also unconvinced that those superior qualities allow us to extend the drain intervals. They apply when difficult conditions exist and prevent excessive engine wear or outright failure.

The regular combustion contaminants determine the drain interval for a given additive package. Since Europeans are obsessed with long drain intervals for enviropnmental reasons, they really beef up the additive package and then extend the drain interval. The Vauxhall Corsa I rented in England last year has a 20,000 MILE!!! drain interval. No way is that engine going to reach 200,000 miles with that schedule, no matter how good the oil.

The problem in North America is that synthetics are marketed as drain interval extenders to justify the higher price rather than engine life extenders under exteme conditions.

I drain the Mobil 1 in my Nissan very 4000-5000 miles because it is used in city driving mostly and our winters are cold. Nissan has a 4000 miles SEVERE service interval and an 8000 mile EASY driving interval for this car!

I agree. It’s the misleading marketing that bothers me more than the claim of superior lubrication.

Perhaps someday in the future one of the synthetic manufacturers will have data to show that synthetics can extend intervals without adversely affecting engine longevity, or even that synthetics improve engine reliability or perhaps even mileage. Currently no such real and statistically significant data exists that I’m aware of to back these claims.

The economics DO make sense if you assign any value to your time, let alone for the inconvenience of schlepping the used oil somewhere. Fewer oil changes the better.

On one car I change oil myself in my spare time when others are watching sports on TV. The used oil goes to the central depot, along with other items to be RECYCLED! I do agree that the fewer oil changes, the better. It would be nice if my cars held 8 quarts of oil, so I could really extend my drain intervals! My total oil change time is about 25 minutes, twice a year per car. I admit spending more time giving both cras a good wax job once a year.

If you have others change your oil there is also very little time involved. Two oil changes per year still allows me to do all the things I like and it allows me to do the under-car inspection to see if CV boots are Ok and no strange leaks are developing.