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Synthetic engine oil

Anyone have any preference for full synthetic motor oil? Wal-Mart lists their brand Super Tech for $17.47 for 5 quarts ($3.50 a quart) vs. Mobil 1 for $25.17 for 5 quarts ($5.00 a quart). Is there that much of a difference? Both meet all of the specifications and have the same badges of honor, so is Mobil 1 that much better? Rocketman

Some engines require synthetic, and some do not. Most work better with synthetic. If your car needs 0W20 oil, it will have to be synthetic.

If it comes to protecting a $5000+ engine, what’s a few bucks matter to get the best oil possible.

A V8 Ford Crown Victoria used for normal driving will reach 250,000 miles easily on cheap dino oil, while a high revving turbo 4 would be much better off with a high quality synthetic. It’s not what YOU prefer, it’s what your engine prefers!

For nearly all applications, your engine will not notice the difference between the Walmart oil and Mobil1, except those engines that specifically demand a European spec oil.

I’ve looked into this extensively and have come away with my head spinning. Bear in mind that even within the Mobil1 brand there are several different quality levels (not meaning viscosity levels). I just stick with the best grade of Mobil1. It doesn’t cost that much more. My GM engines have been virtually sludge free even at 300,000 miles, changing my oil at 7,500 miles.

The API and SAE “badges of honor” only signify that the oil meets the specifications for what its label claims it to be. They are not a comparison. Determining whether Mobile 1 is better or even different from Supertech 100% synthetic is a bit more complicated. Determining whether one is technically better than another for your engine would be even more complicated. First you’d need to define “better”. Then you’d need to perform analysis for specifically those criteria.

However, if “better” means ‘will my engine last longer", I can only say that IMHO as long as you use at least the type and grade of oil specified in your owner’s manual the answer is “no”. I’ve driven engines for hundreds of thousands of mile without ever popping a head on pure dino. My current engine has 218,000 miles and runs beautifully. A peek under the valvecover shows no sign of sludge whatsoever. My ol’ pickup had 338,000 when it was totaled by an errant Nissan.

I agree 100% with Doc, but I will add that if using the best oil you can buy helps you feel better it’s worth the extra cost, even if the engine doesn’t care.

“Synthetic” these days doesn’t mean quite what it used to mean so its likely that Wally World brand synthetic is one of these. Even Mobil 1 10W30 and other grades are not quite what they used to be. 0W40 Mobil 1 is real synthetic and it costs accordingly. That said, I use Mobil 1 products and have for a great many years except in older engines with flat tappet lifters. Then I use Rotella T6 synthetic diesel oil.

Engines are expensive and hard to remove and rebuild so I spend a little more on name brand, high quality oil. With 7500 mile changes, $7.70 extra per change over 200,000 miles is only $205. That won’t pay for the gaskets on an engine rebuild! To quote an old advertising tag line; “You can pay me now, or you can pay me later…”

It is my understanding that manufacturers and distributors can’t label a motor oil synthetic without the base oil being synthetic. Otherwise, if the base oils aren’t but subsequent additives are, it must be labeled as blend. So, the cheaper oil is a true synthetic. I would try and look for any tests on this brand or forums that discuss this issue for various cars close to yours. In the absence of more information, I have felt safer with a name brand. Now, when I use motor oil for other purposes, like rust proofing, who cares. Synthetic motor oil is moderately more biodegradable then standard oil though not a true bio grade, So in that respect, it’s better regardless of who makes it.

The other thing to consider is your oil change interval. If I were changing it myself every 5k miles, I would not hesitate using the cheaper synthetic oil for my car or snow blower for a synthetic cold weather advantage oil which needs to pass minimum standards regardless. In leu of no more test info and a longer 10k interval for a car, I would go with a name brand.

How do you know that the WalMart oil is not manufactured and packaged by Exxon-Mobil?

That’s my suspicion, JT. I believe that Wal-Mart wouldn’t risk their oil-cjhange business on lousy oil, after all, the customer pays for it (the oil) with the oil/filter job. Rocketman

This Comment Isn’t Based On Fact, Only Experience And I’ll Probably Get Some Negative Feed-back, But Here It Is, Anyhow…

I figure that Wal-Mart products aren’t made by Wal-Mart, but rather a business already manufacturing similar (Not always exact. I’m sure they have their own specs.), so I compare labeling, code numbers on bottles, etcetera and compare with other brands to try and determine the possible source of the product.

Strangely with motor oil I’ve found the molded size/shape (not color of plastic) of the bottle to supply the biggest clue. I usually find one unique bottle shape of another manufacturer that is a match for Wal-Mart bottle.

Scientific? Conclusive? No and No. Does it identify the manufacturer? Maybe. It makes me feel better and illustrates just how much *&%# spare time I have when the golf course is closed.

FYI: I always use Mobil-1 Extended Performance in my cars @ 5,000 mile intervals. I buy Wal-Mart Super-Tech SAE30 for my outdoor lawn equipment because it’s inexpensive, I can buy it in a 6 bottle handy case and SAE30 is relatively hard to find unless it’s some expensive, overpriced stuff.


I did a web search, and the two I found were Specialty Oil Co. And Warren Performance Products. A thread at the High Church of Motor Oils says that Specialty is actually part of Shell Oil. Read all about it here:

Or Texaco, or SOPUS, but SOPUS is a division of Shell. Nine pages of that Oiled Time Religion is a lot to wade through.

Yeah, is the pace for this discussion…

Many years ago when synthetic motor oils were first being developed (Conoco Polar Start) was one of the first on the market) a petroleum engineer told me that while synthetics had superior viscosity spread they required much more work with additives to make them equal to the LUBRICATING ability of mineral oil…

I completely trust Walmart to provide quality products at a fair price-NOT. Walmart will do anything to achieve a lower price on everything. Quality is never in the specs.

Just curious though about the different grades of Mobil 1? I don’t buy Mobil 1 at Walmart but still how do you determine its a lower grade?

I Don’t Believe Wal-Mart Mobil 1 Is Any Different From Other Sources Of Mobil 1.
However, I Consider The “Mobil 1 - Extended Performance” Oil That I Buy To Be A Higher Grade Than Regular “Mobil 1.”


I have nothing against synthetic oil if it’s required. If not, it’s just a waste of money in my opinion.

My Mazda Cx 9 has a 3.7 Duratec engine, calls for 5W-20 (Dino is fine per manual). That is what I used 1st when I got the car CPO at 23K miles and I had terrible valve clatter on start up (not really cold start up since I am in CA). Switched to Motorcraft Semi syn and the noise went away. Might be coincidence, but not going back to dino. I did the math and if I use Mobil 1 with a bit of extended change intervals (5.5K), I actually save money.

While buying M1, I noticed the WM brand synthetic on the shelf, but didn’t have time to research it. If it is equal in quality, it is a great price.

We Seem To Keep Beating This Dead Horse - Syn v. Dino Oil. Again, I Must Add That Since I Live Where It Gets Extremely Cold For Months In Winter & Sometimes Quite Hot On The Interstate During The 2 Weeks Of Summer, I Opt For Synthetic.

My car’s Owners Manuals specify dino, except for very cold starts and then they spec synthetic. Synthetic handles high temperatures better with less chance of sludging.

Trust me, I’ve taken dino 5w30and Mobil-1 5w30 from the garage during winter and poured them. Although both are 5w30, the Mobil-1 pours (flows) so much easier. That’s what I’m after when I start my car after cold-soaking all night in January.

Whatever floats your boat. I’m a Peace-of-Mind guy. I carry extra insurance, too.


Many people think synthetic is a waste of money but if you can leave it in 50% longer and it costs 50% more you’re breaking even.

One thing I strongly recommend is not leaving it in 50% longer.
Because synthetic has a lower level of impurities than dino, it withstands high heat better, but it is just as subject to dilution from blowby and to contamination as dino is. The goal of oil changes is to make the engine last longer, not to make the oil last longer.

Whether an oil goes longer between changes is related to the additives that prevent degeneration, not just whether it is a mineral or synthetic oil.

One reason synthetic oil lasts far longer is that the vapor temperature is up around 600 degrees F. Conventional oil has a vapor temperature of around 325 degrees F which is why it breaks down so much sooner and forms sludge. The temperature of the oil in an engine is in the area of 275 degrees F, close to the vaporization point, and probably higher in hot spots.

The temperatures I’ve listed may be a little off but are close to what I have read.

I’ve also read in a number of places that synthetic oil has 7 to 9 nine times the film strength of conventional oil but I’m not so sure about that one. One article I read disagrees with this. Can anyone comment on that?

Just how much of oil contamination is due to oil breakdown and how much is due to blowby I don’t know. Todays EGR systems are pretty effective at sweeping out blowby.

And so, the great motor oil debate goes on!

Edit: Just want to clarify I’m not suggesting going beyond the recommended owners manual interval (in my case 7500 miles)which is what I do. If I were using conventional oil I would be changing it at 5000 miles.

Edit #2: Meant to say PCV - not EGR.