I went to the S7 axle bushings in the mid-'90s. I liked the way they felt... oh so smooth but a tad tight. The first set seized up in the fourth heat because they were tighter than any other bushings. They were smooooth till they seized and I liked them. I used toothpaste to open them up just a little and was able to get better life out of them at the expense of making them loose.
I called Rudy and talked to him and he was testing a pure synthetic from the space program and was liking it. Being an old NHRA gas racer, I liked Amsoil. I got a straight 5 wt. from the local dealer in Orlando, FL. He ordered one can on a regular order so I didn't have to pay shipping. Just had to wait a month. Reading Hot Rod and Popular Hotrodding. I saw the Prolong ads. It had Teflon in it. And was thin like the Amsoil. I mixed up a quart with the recomended amount of Prolong

oil additive... And after 12 years I still have a 1/2 pint of oil left. Since using this concoction, I have NOT had a S7 bushing problem whereever I put one. People were having all sorts of problems in G12 motors... But NOT me. I am still running some of the axle bushings I put in in the '90s. I have not had a bushing problem in any sealed or any motor in years. I oil once every four heats on axles and can only bushing in a race.
The main reason that Teflon is not used in combustion motor oil is that around 600 degrees. It solidifies. Piston rings get hotter than that and then it acts as a grinding agent, ruining the motor. That's why they are not found in motor oil additives any more. If a slot motor bushings ever saw 600 deg. everything would be melted anyway so Teflon works on them. At this rate, I might have to buy another quart of oil and Prolong if they are still in business in two-three years.
Phil I.
I mixed up some with Mobil 1 5W15 for a friend and he also never had bushing problems.

If you check, you will find that there is not a true all-synthetic motor oil but a petroleum base oil with a lot of synthetic chemicals. Chris Radisich straightened me out on that a couple of years ago.