Ive been using the Mobile 15W-50 in the Honda 450ES, it helped the shifting alot, now have about 200 miles on it with this lube. All working very fine, clutches etc.
I now have a Traxter and have not tried the synthetic lube yet, wonder if anyone has any experience with either Prolong and/or Synthetic Lube?

 

I'm not sure about the ingredients of Prolong.. but DO NOT use anything in an engine that contains Teflon. (PTFE) It will lead to engine failure down the road...
Teflon is suspended in the oil base, and as long as it stays mixed up, really doesn't hurt anything.. its when you leave your machine sitting for a week without starting it that the Teflon settles to the bottom of the oil. Then, when you restart the engine, the oil pump sucks up a huge load of teflon particles and sends them straight into the oil filter (if equipped) stopping up your filter, sending it into bypass mode.. so you have no filtration and dirty, unfiltered oil gets sent thru your engine.
If you don't have a filter, the huge load of teflon gets sent into the tiny oiling passages, and eventually stops them up.. so a bearing, or camshaft lobe ends up running without oil...
There is proof of this somewhere online... its been known for several years now...
But, like I say, im not sure about the ingredients of Prolong..

 

I agree Mudmachine, stay away from the snake oil and just use what the manufacturer recommends.

 

mobil1=no problems.

 

As far as Prolong or Energy Release (Same thing) they work well and don't cause clutch slippage as some people feel. Prolong is basically an oil and metal cleaner per-say. Everybody I race with use it and I've talked to several people who treated their entire vehicle (Tranny, engine, etc.) and have actually gained 5-10 miles per gallon, especilly in older gas-hog pickups. This is due to less friction between metal parts because they are clean. Thus its not like other lubes like teflon that can cause clutch slipage. A person I know said that after a few treatments his oil now comes out as thick as when put in, not all broken down and runny as before.

Hope this helps,

Sickman