Taryl, a funny guy on youtube did an experiment with 10 brand new engines and used all kinds of different fuel additives/ethanol treatments. Plain 87 octane failed at about 18 months (around the same time most of the fuel w/ additives failed). So it should be fine if you keep it fresh. Non Ethanol is best if you can find it and don't mind paying $4+/gal (thanks Brandon!). I like to add a 1oz outboard smokeless 2 stroke oil per 5 gal can.
There were a lot of technical problems with the way he did that experiment so don't elevate the findings above the level of interesting trend.
Setting up a truely accurate experiment is a very difficult thing to do
Simple things like the distance from the unlined tin wall can make a big difference particularly if that wall was either in full sun or full shade
The mason jars meant nothing apart from the fact that some of them were obviously not sealing properly .
In the first year of college we were given experiments to do to show us various things about physics & chemistry but mostly to familarize us with the equipment & the sort of things that can affect the results.
In the following 3 years we had to design our own experiments and in those 80% of the score was for the design & only 20% for the results.
When you understand the what , why & how it becomes easy to design what appears to be a valid experiment in such a way that yore guarranteed to get the desired results regardless of weather they are actually true of false .
Making a totally unbiased completely objective experiment is unbelievably difficult to do and most of what is on You tube or face ache is poor at best .
All of what you see on TV & in advertising is total trash but unfortunately people believe it .
Just about every engine maker sells their own branded fuel & oil because it is a never ending source of income
And yes the equipment will work best if you use these products according to the directions ( which no one ever reads ) .
Will you get your money's worth is a totally different question and will vary according to your values & situation .
A mechanical idiot who lives 50 miles from the nearest dealer will value absence of failures way above stronger running .
Some one who is mechanically astute might valve fuel economy above all .
We are all different .
Nothing wrong with plain old pump fuel during the mowing season, leaded or unleaded provided it was good when you bought it and fresh .
All of the problems come from storage, where it is stored & under what conditions.
Now with the latter E anything will be a lot more sensitive to the storeage conditions than strait fuel.
My advice to my customers is to buy the smallest quantity you need as you need it during the season.
t the end of the season either fill the tank to the brim or drain the tank completely.
Run the carb dry or on Honda ( & clones ) drain the carb with the drain bolt that is why it is there .
Do that and you will have many years of use without any fuel problems
You can even put some cling wrap over the filler cap then screw the cap on if the cap is vented.
For hand helds tip the fuel out then start the engine & run the carb dry every time you use it unless you are using it daily.
And when you have finished, store it in a cupboard or hard case to prevent mud nesting insects nesting in the exhaust or air intake .
