Hi all, this is my first post on this forum. I searched this forum but could not find my subject to my satisfaction. Maybe one of you fine folks can help. I have been looking for fuel requirements for HPI rs4 evo+ engine. I cannot find it anywhere. I emailed HPI "support" and Josh told me HPI only has experience with their own fuel and cannot recommend any other fuel than HPI. Well if HPI fuel is not available anywhere, I have to come up with a substitute. I read somewhere a few years ago that HPI uses 14% oil content. I cannot find that anymore and am not sure I remember what I read correctly. Do any of you folks other there know what substitute fuel would satisfy the HPI requirement?
Thanks all !!!

Blue Thunder Race, Trinity Monster HP, Byron’s, O’Donnell’s, etc all makes suitable fuel. Use fuel with 10-12% oil with part of that being castor and you are set. Do not use fuel labeled “RTR blend” as it has too much oil in it. 12% oil is the max you should use for regular running. 14-15% oil is suitable for breaking in over the first 2-3 quarts..

if you use a fai fuel works?

FAI fuel has no nitromethane in it and is 20% oil 80% methanol. Too much oil for car engines, but perfect for airplanes and boats.