I use Aspen 2 with chain saws and Aspen 4 (92 octane MON) never had hot start problems with that.
Haven't used pump fuel at all for two years. I don't know how it is in United States, especially in warm-climate parts, but here it's stipulated that gas stations must sell "summer fuel" in June, July and August and "winter fuel" rest of the year.
With small engines, dirt bikes, classic cars etc. summer variant may not ignite very well in cold starts when temperature goes to 0C. And vice versa winter variant can cause vaporization problems in hot conditions.
I recently got 2 trailer loads from a 3rd dump site of what I thought was all red elm. Turns out it was another elm since it lost its brown color upon drying. Some of an unknown wood mixed in. Had it stacked on the side of my rock driveway so I spent some time this week splitting and hauling it this week. Hot week so I only worked an hour at a time. Here's my splitting area. Set up a tarp to catch all the garbage and a garden cart on the left to toss in all the bark which is destined for the burn pile. I do like elm because it lost most of its bark before I split it.
Placed the trailer to the right and tossed the splits in as I go. Notice the operator positioning jig (short round in front) that I use to align my rear the proper distance from the splitter. I only have one of those $1000 farm store splitters so its kind of slow. Which is OK as long as it works. Only bogged down twice in the elm and I have to stop/start. But it went through. The unknown wood (light in color, dark brown heart wood, powder post beetles) was harder to split. Stringy. I thought maple. Meant to get a pic.
I did manage to get the wedge stuck in a piece of this wood late yesterday so I stopped and started again earlier this morning. I managed to get the stuck round off but couldn't start the splitter. Ended up pulling the cord off. Then I noticed the top end had lost a couple of bolts (again) so I just put it away and hauled the wood down the hill to the stacks. I'll work on another engine I have for the splitter first. Easier fix.
Did I say how much I hate doing firewood in St. Louis Summers. If I hadn't lost the first two sites, I'd be done already.