Hi all: I have lived in Southern California since 1961 so all of my cars have been tuned for elevations of sea level to perhaps 4000 feet. Numerous times over the years, I have made trips to Wyoming over Teton Pass, Denver, once over Wolf Creek Pass (about 11,000 ft.) and then through the Eisenhower tunnel (maybe 10,000 ft.) on Rte. 70 and have never had a problem because when I reach an elevation where my car's performance starts to drop off, I nudge the timing forward a bit. This seems to solve the problem. On the way back, when the car starts to ping, I reset the timing. Except for one occasion, I used the highest octane fuel available. In 1997, when I drove to the Denver meet, a friend told me that at higher elevations lower octanes were advisable. Boy did I bite. Just after getting on Rte. 70 in Utah, I filled up with 86 octane Shell gas. By the time we got to Moab, the F sounded like it was on its last legs. Even with the timing advanced, it took 3 tanks full of 91 octane to clear the problem. Notably, in 1967, I had my first experience with high altitude driving. I was driving my '66 Newport with a 383 engine, 4 bbl., up the back road to Tahoe from Hwy. 95. I got behind a Cadillac going about 15 mph and I could not get up the speed to go around him. I pulled over, nudged the timing up and subsequently caught the Caddy and flew by him. SO, if you are coming from a lower altitude for the meet, which most everyone will, I suggest having the necessary equipment along to change your timing. If you do not, as I did not the first or second times, just nudge the timing until the engine idle comes back up to a normal sound. Just my 2 cents worth. Dan Reitz Northridge, CA [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Yahoo! Autos. Everything you need to know about buying or selling a car. FREE Quotes, 360° Tours, Research, Blue Book, Compare Vehicles, Buy Used http://us.click.yahoo.com/kEZsdA/bwnGAA/YiGOAA/8LmulB/TM --------------------------------------------------------------------~-> To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/