I am going to guess the mower is a Lawnboy, which specs a TCW-3 oil. If so you can find this "boat oil" at your auto parts store or Wal/K mart for not much. This oil should probably not be used in the handheld equipment.

Or you could get this, use it all the equipment, have a great oil, and spend less than you are now.

Here is a link that might be useful: good 2 stroke oil

Typically, a 16 oz container of 2-cycle oil is good for making about 12 to 14 gallons of mix. Most owners will use maybe two or three gallons of mix a year in a 2-cycle mower. I must confess this is a first for the cost complaint on 2-cycle oil by a non-commercial user.

Actually, it's a Snapper mower, not a Lawnboy. I didn't know that Snapper made 2-cycle mowers, but here it is in my garage. FYI the engine is a Tecumseh TVS840. The 16 oz container of 2-cycle oil I got says it is good for 6 gallons (about 2.6 oz per gallon). I've only been using this mower for the last couple of weeks, so I don't know what the long term consumption will be, but I'm pretty sure it will be more than three gallons for the entire season!

The cost complaint about 2-cycle oil is less about what I can afford and more about what I suspect may be a ripoff. If this stuff is truly special, then fine, I will look for the large economy size. If it is simply typical motor oil that is being repackaged with a huge markup, that is something else again.

Two stroke oil is not the same as the oil used in 4 strokes. Among other things it's designed to burn cleaner as not to carbon up the engine piston, rings and exhaust passages.

Not magic, just different.

The Tecumseh TVS840 is designed to use TCW-3 oil and in fact was originally designed for TCW-II.

You must use 2 cycle oil. 4 cycle oils will leave ash deposits on the piston and combustion chamber. Also the mix of additives is different between the two types of oils, appropriate for the service they will see, and detrimental if used in the wrong engine.

Personally, I use TCW-3 in my low speed equipment. I currently have a Snapper mower with Wisconsin (Subaru) Robin WTI-125V (EC13V) 2 cycle and a Toro 22043 Commercial with Suzuki 47PT7-7 engine, and both recommend TCW-3. I also use TCW-3 in my "throwaway" weedeater (Homelite) and leafblowers (Craftsman). These don't spin more than 7,000 or 8,000 rpm, so TCW-3 is OK.

I do run high end synthetic 2 stroke oils in my Stihl chainsaw and my Echo and Olympyk string trimmers. These are capable of 12,000 rpm, hence the "good" oil.

BTW, I have a PDF of the Tecumseh TVS840 manual. If you want a copy, email me thru Garden Web, and be sure you give me your return email address.

I've posted a link for the Wal-Mart TCW-3 for your reference.

TCW-3 can be had as cheaply as $12.00 gallon from Wal-Mart, which is what I use . My last gallon has lasted more than 5 years.

Here is a link that might be useful: Wal-Mart Super Tech TCW-3

Thanks for the info! I already have the TVS840 manual. I will see if my Toro weed whacker can use TCW-3, since I would prefer not to have two grades of 2-cycle mix. Of course, with TCW-3 at $12/gallon as opposed to the other at least $70/gallon, I can buy another gas can! I assume there is no problem using the higher priced oil in the Snapper mower?

What ratio does the Tecumseh 2-cycle require? Roller-bearing engines usually are 32:1 but older bearing-insert engines are usually 16:1. BTW, you're right, I misstated the gallons of mix in a 16 oz bottle by a factor of two!
There are many types of 2-cycle oil. What most of us use is a synthetic blend (like the widely available Homelite or Echo brands) at 40:1 in everything. I've had no problem using this mix in everything from a 2-cycle mower to a chainsaw. This is over a more than 10 year period, so if I were going to burn a piston from lack of lubrication I think it would have happened by now. I also would not make and keep two different mixes for 2-cycle equipment, and I also would not use the cheap bulk 'water-cooled' oil in anything.
The thing is, the old Lawn-Boy oil was 8 oz to 2 gal (32:1)because the oil contained lots of solvent, making it thinner and easier/quicker to mix with the fuel. The solvent also helped keep the engine clean. Modern oils are much more concentrated and require more care in mixing, but they are designed to be used at higher ratios, like 40:1 or higher. So you have to figure out how to make your mix since the old 2-cycle mower engine probably took oil just like the Lawn-Boy oil at 32:1. If you mix the new oils at 32:1, you will be wasting some of it, because its more concentrated. That's why I use 40:1 for everything from 32:1 TO 50:1. I also like to throw some Marvel Mystery Oil into my 2-cycle mix to boost solvency - all engines love it, esp. 2-cycles.

Ggoyneche is correct - the Tecumseh manual recommends TC-WII or TC-W3. The recommended ratio is 50:1.