Amsoil Vs Mobil 1

I heard that AMS oil is 100% synthetic whereas Mobil 1 is not (full synthetic).
Motul also has 100% synthetic engine oil.

I have been using Mobil 1. Wondering if I should switch to AMS?
I suspect that this would clean the engine better than full synthetic?

Is AMS oil available at Autozone or place like them?

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The Auto Zone web site will answer that . Isn’t this your 20 plus old vehicle and if it is all you need is the correct weight . Even a house brand will be fine.

You heard wrong.

I use amsoil in my 2 cycle boat engine, used to use castroil in my cars, now it is like whatever whatever, get me 200k and I am happy

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I use Mobil 1 and it is full synthetic. The thing about Amsoil is that it is sold by dealers like Amway. Maybe it’s OK stuff but the marketing plan adds way more mark-up than is justified. Maybe that has changed some now, I dunno, but still just a lot of hype.

the heavily advertised aspect of Amsoil is the promise of longer oil change intervals.

it may be important to truckers with high oil volume in the system, but makes not much sense in the small engines.

you will not get any noticeable difference when using AMS and I would not recommend buying into their push of extended oil change intervals either

stick to what you can procure locally

I heard otherwise . . . and different terminology, at that

Mobil 1 is fully synthetic, no doubt about it It’s group 4

Whereas some store brand synthetics . . . and Castrol syntec . . . are group 3, which are considered by some/many to not be true synthetic oils

I’ve never seen Amsoil in any auto parts store in my neck of the woods, and I know pretty much all of the major parts stores here. I suspect it’s special order

Mobil 1 has extended performance products that have a larger amount of the additive package to prevent oil breakdown much longer than the normal performance Mobil 1.

yes, and I would use that M1 type if I needed extended intervals, as it is something available in the local store

still, OP brought up a question about Amsoil, and to the best of my knowledge, the extended change intervals was the most advertised “feature” of it

Amsoil is fine stuff. Better than Mobil 1, no. More expensive, yes.

The only place I see it on the shelf is at motorcycle shops… not Harley shops though.

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If I may be so bold . . .

Why should I use Amsoil . . . ?

It’s not easy to obtain . . . I can get Mobil 1 almost anywhere

It’s not better than Mobil 1

And it’s more expensive than Mobil 1

I just don’t see a point in using a hard to obtain oil that isn’t actually better than what I can easily get


There are Amsoil retail partners but they’re mostly small shops (at least around here)

What I heard was Mobil 1 (M!) is Group 3, hence Full Synthetic
AMS is Group 4 and hence 100% Synthetic.

M1 base oil uses derivatives of Crude oil - AMS is 100% man made. AMS will ship it to your door.

Amsoil is more expensive because of its inflated sales cost structure.

I’ve not seen evidence it is better than Mobil-1.

For years Amsoil was not API certified. I don’t know if that changed recently. Their websites have cleverly worded language about API certification.

Are there vehicles that “NEED” Amsoil? When only Amsoil sales reps are willing to answer “yes”, doesn’t that say something?

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I think you’re splitting hairs debating Amsoil vs. Mobil 1. This is a “bragging rights” discussion for car fanboys.

The truth is that unless you’re running in an extremely rare group of high performance car types…it doesn’t matter. Most of us could wreck our cars tomorrow, and the last question anyone will ask is “what kind of oil was in the engine?”

Life is too short to worry a lot about your brand of oil.


Here’s an explanation of oil groups. I don’t really care what group of base oil my motor oil is derived from. If it does the job, I’m happy with it. Given the severe refining group 3 oils receive, I’m certain they are excellent bases for almost any application.

This person now has about 15 threads related to engine oil . This seems like an unhealthy obsession .

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Buy pricy oil for a used car I won’t have long? Well, there is that.

It sounds like you were listening to somebody who’s either got a bone to pick or is shamelessly promoting Amsoil over Mobil 1

Mobil 1 is group 4, so whoever told you it’s group is 3 is at best wrong, and at worst is trying to disparage the brand

Can I be blunt . . . ?!

Were you pretty much set on buying amsoil before you started this discussion?

I’m using Amsoil marine oil in my four stroke outboard because it was the oil that the boat shop had in stock that had the MMA 4C-W rating. What’s so special about that rating? I have no idea. Boat motors run for extended periods at high power, but so do airplane engines.