Amsoil VS Walmart Mobil One?

While at Walmart I ran the numbers for Motor oil and Gear Oil.

2X 15W 50 (5 quart jugs) @$25.00 = $50.00
3X quarts 90w High Performance Mercruiser Gear oil @ 10.47 each = $31.41

AutoZone KN 3002 filter at $15.00

Total for Motor oil and Gear lube $81.41

With filter $96.41

I have always used Amsoil in the past but the cost in comparison is more than twice or not more than the Walmart cost.

Is the quality of Amsoil and higher cost still worth it compared to the above alternative?

This is really an apples to pomegranates comparison. AMSOIL fans will tell you if you worry about cost, then you shouldn't be boating. There are literally hundreds if not thousands of threads like this in any forum at any time...and when you say 'quality' as the comparison item...well, get ready for the responses!

<grabs popcorn>

Can even go little cheaper and use a wix /napa gold (same filters as eech other) .

Also $35 or over orders ship free from walmart. Gas at 4-5 gallon, saves even more $$$ not having to drive for it.

Flat tappet cams, i would want more zinc/phosphorous than mobil 15w:50 offers even though has much more than standard street oils.

You've got a 496mag. Any decent oil changed every 50 hrs will work fine. IMO, Amsoil is a waste of $$ for a stock 496.

My 496HO lives on Mobil Delvac 1300S 15w40. $12 a gallon at Walmart.

Agree with Griff. I do not do much mechanical work on my boat. I leave that to my certified Mercury mechanic who works on everything from bow riders, center consoles to high end performance boats ( cigarette, Apache, etc ), mostly v bottoms since we don’t see many cats in my area. Anyhow, he’s said many times before, unless a customer asks for it, he will use regular oil, nothing fancy, especially if it’s a stock motor like the 496.

Over the last 20yrs that I have been reading threads on OSO, there has only been 1 thread that I believe failure was due to the oil that was chosen. And that was the build of a tight tolerance 0-20 wt engine years ago. And failure was the tight tolerances and viscosity chosen not the brand of oil. Any quality oil should be fine. I've always been an advocate of the Walmart 15-50 Mobil 1, but I run Mobil 1 in everything.

15-40 Rotella in stock engines and Valvoline VR1 20-50 in high performance engines has always worked for me. From what I understand, the Mobil 1 formula was changed a few years ago and the high end racers won't touch it anymore. However, it would be more than adequate for a stock 496. I do like and use the Amsoil gear lube though.

I bought most of my 15w50 M1 from WalMart when I had my 496HOs for 13 seasons.
Wix Napa Gold 51060 filter. (You can buy them in bulk for cheaper & forget the K&N filter.)
1 quart of Lucas Oil Treatment with 7 quarts of Mobil 1.

Just like your last thread on this topic...
...you can't go wrong with the above recipe.

My old boat has something like 800 hours on the 496HOs with the above maintenance.

And I only used Mercury High Performance Gear Lube. Many drive builders swear by it, even with all of the other options on the market.


I run AmsOil exclusively in my race car though.

Personally, I think 15-50 is too light. As a bargain, 20-50 Mobile 1 at Walmart is a good deal, but for a few bucks more, you can have Amsoil Dominator 60wt. Which is great stuff. With BigBlock applications, 496Mag/HO and 525 style engines the oil pressure maintains better even after hard runs, its specifically made to assume a lot of gas ends up in the oil, the oil lasts wayyyyy longer than conventional 20-50 so at the end of the day, Dominator 60wt really doesnt cost more since it can stay in your engine much longer. When my Mobil 1 was dirty, the dominator was still red and clean.