Here's the deal: I'm flying FS8 (2002). Most of what I've done under IFR rules so far has been up and down the West Coast of the US to airfields at or around sea-level elevation. Transitioning from feet to flightlevels at 18,000 I'm careful to re-set the altimeter to standard pressure (29.92 in hg). During descent I'm cleared down, initially to 15,000 or 16,000 by the high level center controllers, without information as to the current altimeter settings, and am usually given a lower clearance and passed off to the lower level controllers BEFORE reaching the first assigned altitude. Upon contact with the lower level controllers I'm told the current altimeter setting, I set the altimeter, and all is well.Last night I decide to fly the ERJ-140 (American Eagle) from San Jose (KSJC) at 59' elevation, to Reno/Tahoe (KRNO), sitting at 4417' elevation. I file a plan at FL215 for the trip. Atmospheric pressure last night was 30.34 inches at KSJC. On the way up, I recalibrate to standard pressure crossing 18,000 as normal. I start the descent as requested to an initial altitude of 16,000. I'm still in contact with the upper level controllers at Oakland Center at this time, so they don't tell me what the new altimeter setting should be. I have a smooth descent and LEVEL OFF at 16,000, relative to 29.92 in. ATC starts getting shirty with me ("Please expedite your descent..") eventually terminating my IFR plan.Now, in reality, I'd just get back on the horn to ATC and have them give me the correct altimeter setting. In MSFS this isn't an option. What would you do in this situation? Take a guess at the altimeter, based on what it was at departure? I was too far away to get ATIS from the destination field. Should I try to tune ATIS from a near-by airport to get an idea of what it should be? What if there isn't a nearby airport?As a footnote, I continued "VFR" in to Reno, then filed a lower flightplan for a second leg to Las Vegas (15,500 feet - used more fuel but stayed IFR all the way). I noticed a surprising number of AI planes getting IFR termination as well - more than I normally hear. At least 4 got terminated, and two more got some serious nagging, all for not achieving assigned altitudes. Does MSFS have a problem in High Pressure situations? Anybody else noticed this?Sorry for the "novel"!!

Press 'b', it calibrates your altimeter to the local pressure setting. Then you can continue flying altitudes and not Flight Levels.AI Traffic doesn't set the standard pressure setting (1013mb or 29.92") at high altitudes so when there is a large pressure difference between the standard pressure setting and the actual pressure setting ATC gets shirty with them all as they don't fly at the right level.Hope that helps,Ian

IanThanks for the tip - I'll be sure to give that a try. I'd guessed that there was something like that happening with AI as it was higher levels they were getting "ding'd" for.