hey Dave, so thats what your ugly mug looks like!!!!
That big yellow dirty birdy looks like my Bridi Escape on steroids. Nice looking plane, but I would have used pink polka dots.

BTW, the origonal reason that the bigger tigre's got to recommending a low oil fuel was to keep the fire lit on those that had "carb issues" Many of them had horrible midrange richness problems and one of the easy ways to cure that was to cut down on oil content, requireing both needles to be slightly leaned to compensate for the low oil volume in the fuel and sneaking up on a cleaner midrange.
I have found a number of solutions to the few stubborn big tigre's out there. First, a hot fuel and a cool plug, why I have no idea but it seems to work. The other way, with the horribly rich midranges found on some big tigre carbs is to use very low nitro (I like 0% to 3%) and low to regular oil contents.

I figured this all out by accident since I ended up with two ST 3250's at the same time. One ran like crap and the other ran great on "normal" fuel. Playing around with the fuels and plugs made me determine that the carb was the determining issue. Swapping carbs proved it. Moral to the story, some of the big ST carbs were out of tolerance and instead of fixing the problem, hobby services made the recommendation to run low oil fuel which made the problem much less noticable and worked just fine in the other big tigre's that actually had a good carb.

When a carb swap fixes all the engines ill's, fuel is not the issue.

If you have one that does not run very well with the carb you have on standard 10% or 15% fuel, throw away the carb and install a good one.