Since we're talking about elevation and smoke and power I'll post (maybe repost) a picture. This is my truck at the top of Donner Pass, on I-80. The elevation is just over 7000 feet. The trailer was loaded, literally to the roof. The truck is set to run at sea level, and is NA. I didn't notice an appreciable loss of power, but the smoke level did rise. It's times like this that I really want a turbo.
I remember, years ago, taking our '73 VW camper into Rocky Mountain National Park, up from the back side, from the west. That was a long uphill climb, to a bit over 12000 feet, for the old camper with it's 1700cc suitcase engine. It had a hard time running at the top, at that elevation. Needless to say, it was not a happy camper (pardon the pun
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