Substituting all-mileage oil with synthetic

My Nissan Versa had its last oil-change using “regular” oil (5W 30). Wanting to top it off I initially bought something with the label “All Mileage.” Is this the same as what is considered to be non-synthetic or “regular”? I then went back to pick up another All-Mileage oil but all they had left was a synthetic blend. Is it OK enough to top it off with synthetic when I’ve been using the other? Thanks.


They make synthetic blend oils.

Part synthetic, part regular oil.


You can mix regular oil with synthetic or synthetic blend oils of the same grades… 5w30, 2w20 ect.

You can mix “high mileage” oils with regular oils as long as they are the same grade. If you really want to learn more about oil than normal people should (or want to…) you can always go over here…

These people are nuts for the subject.


I’m not sure what is going on but non synthetic is getting pretty hard to find. I use syn in one car and Mobil 5000 in the other. Oil trip before last, all that was available was a blend in Mobil 5000. Last trip, all that was on the shelf was Mobil 1. I checked about 5 places and all that was available was Mobil 1. I finally found 6 single quart bottles of 5000 at one farm store. Looks like Rockauto still is selling it, but really I have never had to order oil before. (I should mention Mobil is hard to find. Other brands are still on the shelf.)

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If most new cars require synthetic, then that’s what will be available. The reseller has limited shelf space and selling synthetic plus mineral oil in the same viscosities makes him use too much shelf space for oil in general.

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I will agree with @Bing on the seeming shortage of Mobil 1 products. There seemed to be less on the shelves than usual.

I went to buy Mobil 1 wheel bearing grease and had to get it out of the back room at O’Reilly’s. None was on the shelf.

If you find yourself critically low on oil, then use what ever you can get. Otherwise use the oil specified in your owners manual. If you are using oil, you should probably carry a bottle or two in the vehicle and check frequently.


Like I said, there were other brands such as Valvolene and Citi products on the shelf. Just not Mobil 5000. And the space that normally would have had the Mobil 5000 in had Mobil 1 instead. So not a demand or shelf space issue that I can see and every other retailer seemed to have the same display. A few months ago the standard Mobil 5000 was replaced with the syn blend and now none at all.

I always have at least two to three oil change quantities on hand so never in critical need. I just don’t like the idea of using full synthetic in a car that has developed a little leakage. Cost is not an issue. Really don’t care.

I noticed the lack of “conventional” oil the last time I bought oil at Wal Mart. At least in the mighty “Supertech” brand. Yes, I’m cheap and go to Wal Mart and buy Supertech oil. “Supertech full synthetic”, “Supertech high mileage full synthetic”, “Supertech all mileage synthetic blend”. I went with the synthetic “blend”. I figure it’s probably a pretty weak blend anyway, and “all mileage” probably means…nothing :joy:. “High mileage” means it has some seal swelling goo mixed in, right? They don’t make a “low mileage”. So yeah, “all mileage”…means it doesn’t have the seal softeners (I guess) and it’s probably pretty close to conventional being a “blend”.

I kind of miss the days of just synthetic and conventional. Too many choices.

Hopefully that “All Mileage” oil had the API “starburst” certification label.

Why the dino oil is disappearing from the store shelves in place of synthetic, my suspicion is that it has as much to do with to do with retailer profit as customer demand.
“Why continue to take up valuable shelf space offer with a lower demand product when I can sell an equal, more modern product and make a few bucks more?”

Exxon Mobil is trying to do everything they can to convey a positive environmental image. A small part of this is putting less money into the development of ‘dino’ oils, and more into the development of sleeker, higher profit synthetic oils, as well as into advertising that says “see, we are promoting synthetic oils, extended OCIs, etc.”

Not all companies are taking this exact same approach; hence, the disparity in shelf space

I thought it might have something to do with the hijacking of the Board and the push to get out of the oil business. Interesting that it was only a couple years ago where they over-hauled their whole dino oil line with new “high mileage” products etc. So something maybe happened, maybe not. Waiting for the annual oil sale though. Usually October.

Usually companies don’t revamp their product lines and then dump those product lines shortly thereafter. Unless they are bought out, go bankrupt, or under new management.

May be as simple as the fact that you can use synthetic in most anything (backwards compatible, so to speak), but you’re only supposed to use synthetic in a vehicle that calls for it. Although I’m of the opinion that if you use the correct weight, synthetic vs dino really doesn’t matter as long as you don’t try to extend the oil change interval.

I just prefer Dino in my older cars because synthetic seems to “slip through the seems” (gaskets, etc) a little more rapidly. I don’t think it “causes” leaks. But it does seem to make them more evident.

Awww, yeah. Good stuff.

I noticed it says “5k mile protection” and they don’t have “conventional” listed on their little oil comparison chart on the label. Maybe “synthetic blend” is Supertech’s new term for “conventional”…?

Also noticed they also have “advanced full synthetic” as the top tier. However it is “advanced” beyond the regular “full synthetic high mileage”, I do not know…

I have never tried it but…

Supertech Oil Review - Who Makes It (& How Good Is It?) (

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I actually read a little about Supertech on Bob Is the Oil Guy a few years ago. It’s been good enough for my junk so far.

It’s a combination of
A) so many newer vehicles require synthetic oil now that it is no longer profitable to sell regular oil and
B) synthetic oil improves gas mileage so manufacturers are under increasing government pressure to push the sale of it.

Yeah I understand all that except there are other dino brands on the shelf. It’s just Mobil that seems under stocked. Who knows, maybe in a week or two it’ll be restocked.

Not the end of the world. I carry 3 grades. 0-20 Mobil 1, 5-30 Mobil 1 for the small engines, and 5-30 Dino for the Pontiac. So switching to Mobil 1 for the Pontiac would mean carrying just two grades. Still I would rather not

Good points.
With gas at $3, if you can easily buy a compatible synthetic for a few bucks more vs. hunting all over creation for the dino oil the cost to the consumer probably works out the same.

And completely agree that the correct weight and change interval is much more important than the manufacturer or type.