If 5.2 oz of oil is for 2 gallons of gas, using 1 gallon of gas would give you 25:1. Using 4 gallons of gas would give you 100:1.

I mix all of my gas at 50:1. It's 1 small bottle of oil per 1 gallon of gas.

I wouldn't go to 50:1 you're halfing the amount of oil...............the least I would go is 32:1 that is 32 parts of gas to 1 part of oil

Ok, first thing, you don't buy oil that is 24:1 or 50:1, you buy oil, then mix it to whatever ratio you want.

Second thing, your old toro required 24:1 because back in the day 2 stroke oil was awful, with current oils you should be fine even running 50:1. I probably would go 40:1 myself as that's what I run all my old equipment on. Even though it is said to be ok to run 50:1 using modern oil in older engines, I like going a little on the heavy side.

Just to add all the confusion that I possibly can -

Yes you will find oil marketed as 50:1, 40:1, 32:1 even 100:1.

Yes you can ignore the bottle and mix whatever you want.

A lot of times the 32,40 & 50 bottles are 4oz bottles just filled with 4oz, 3.2oz or 2.6oz.

What I do is buy a small bottle of say 40:1, mark the oil level in the bottle with a pen and re-use that container to measure the oil I am using from the cheaper quart size.

I always go with the more conservative ratio when a choice has to be made between the oil company label and the machine manufacturer. However in your case I think 24:1 is a bit much. I'd go with 32:1 to 40:1 and not loose sleep over it.

All: Thank you very much for answering this question. I use 40:1 in my weedeater; I'm going to use the same blend for the tiller.

You might be better off using the 32-1 mixture, since your machine was made a number of years ago.
Way back in the olden days, we used a half-pint of 30W engine oil to a gallon of gasoline! Yes, it was OILY, but things lasted a lot longer, too. I have a weed wacker that i bought 20+ years ago. It runs on that formula, and starts every time, runs great, smokes a bit, but it is old!