[keep_hope_alive]

With previous vehicles that wanted premium fuels, I was careful with the gas stations I chose, but it's a crapshoot when travelling. I try to pick the newest with TopTier labels. There is water in all gas since water vapor condenses in fuel storage tanks (including vehicle fuel tanks). And it's hard finding fuel without ethanol in it either due to tanker usage or gas station policies. Fuel treatments can help with this, sometimes. I also have to deal with summer and winter months. In the summer, the higher humidity results in more water in fuel than in winter. We typically use fuel treatments in winter to prevent freezing. A 1/4 tank in summer will have a higher concentration of water than a 1/4 tank in winter since winter air is dryer. It's always a struggle keeping fuel dry and since water doesn't combust, any moisture content will reduce efficiency by reducing power. And given that E10 absorbs more water than non-ethanol, it's a constant fight.

[Bongos2U]

Has anybody used Amsoil's Upper Cylinder Lubricant gasoline additive?

[cdrptrks]

Originally Posted by arpad_m

The manufacturer's claim about its rating boost is 20 points, that is, 91 to 93, so if it works, it isn't useless. According to the specs, it appears to contain MMT, which means it isn't snake oil but also that a bit of research into disadvantages is worth doing before committing to its regular use.

Page 230 of the 2021 manual specifically lists MMT as a prohibited fuel that may damage the vehicle and void its warranty. In my opinion, it would be much safer to "splash blend" a small calculated amount of E85 with 91 octane to get E15 instead, but I have not tried this. You would need an ethanol content test kit to calculate it with full accuracy since E85 is usually less than 85% and 91 octane may be E0 or up to E10 depending on where you get it but it will probably be listed as ethanol free at the pump if it is E0.

I had to fill up with 91 octane once last year in Oklahoma on a trip because I could not find any 93 and I also couldn't find any E85 to splash blend. I didn't notice any knocking or problems but I was just driving at low rpms on the highway and made sure to run the tank very low before I filled up with 93 octane and went to my planned track night event at Eagle's Canyon.