Remembeer Fellas, Penzoil is a petroleum based oil and Amsoil Sabre Pro is a Very high quality synthetic Based oil which is the only reason why it can be run at 100:1.
Hi Sal98,
I'll try to respond. I think the previous replies are because of your assertion above. This has been endlessly discussed on these forums. Many very knowledgable folks with serious technical qualifications have posted. They have been shouted down by folks who often have only lightly formed opinions, not even experience. So...
Bottom line is that many folks have had lots of success with Amsoil Sabre at 100 to 1. Many have had success with all the oils you mentioned. Many have had troubles and failures too. Some of these failures could be traced to the oil used.
You should read and form your own opinions. I say this because facts are often buried by hype and marketing. Outspoken people often feel what they are doing is the best and will shout down all others. In the end you will be very happy mixing any of these fine oils as recommended.
My tips:
Cool the engine properly - don't assume a bit inlet = adequate cooling. Proper engine temp is life and power.
Mix your oil properly - always put oil in he gas (don't ask. Many have made this mistake).
Mix you chosen oil at oil manufacturers ratio. Where you are given a choice try to determine if your use is more or less severe. A properly cooled engine on a nice day does not work very hard.
Learn to set your needles. They move for a reason and there is a sweet spot. Learn to tune your engine. The manufacturer will only give you settings where the engine can be initially started. Pat Roy gave good advice above. Retune if you significantly change altitude. Retune if you change props. It won't take much but they do need adjustment.
Learn to read the plug color. I will often run a hard upline then kill the engine and dead stick in. This will give very good indication of mixture. It is not the ONLY way to do this. Pat's info above works well too. I just use this to sorta verify my setting.
Don't over prop. This loads the engine and creates heat. Find a suitable prop that keeps temps in control and gives you the performance you want.
Good luck. I like Belray MC1, Mobil 1, Pennsoil air cooled, 3W's oil and I'll bet I would be happy with many others.