"The modern engines do not care what altitude they are at. The engines do not “know” what altitude they are at. They do not need this information.

The engine “Know” what the temperature and manifold pressure is. From this, the correct amount of…"

"Thanks. How about the Turbo 195 - does it lean with altitude like the 130?

Bill"

"Only if you would like to do so. The engine will start and warm up on its own."

"Thanks! I have another newbie question. Since the Viking engine is built to automotive tolerances regarding piston to cylinder clearance - is preheating required in cold weather?"

"Hi Bob. Yes you are right. The manual says maximum of 15% but all auto gas here in Brazil has 25% or 27% ethanol. Since I am monitoring closely and I had no issues with 90 hours of flight and it is a very clean fuel, the only concern would be the…"

"thanks jose. isn't 25% a little high for this engine?"

"Hi Bob. My 110 engine has 90hs. I use auto gasoline here in Brazil with 25% ethanol. It has 95 octane. I used 100 LL only once just to test. Saw no noticable difference."

"Yes, it does that and there is no altitude limit for this"

"https://www.vikingaircraftengines.com/first-engine-start"

"The easiest way is to call Viking:)
We tried calling you but busy. I think you have a land line.
In any case, here is a video as well.
Viking phone is 386-566-2616"

"thanks norm, i will probably start with 18."

"Bob, on my CH-750 I have it set at 19 degrees which gives me about 5200 on takeoff and climb. I previously had it at 18 and as I recall it was around 5400."

"M18x1.5 -Alissa"