I just returned from a trip over the Sierra's, through the Yosemite High Country and I must agree that the power, or lack there of is very apparent at elevations of 7000 and above. It is noticable before that, but I had to pass several times on a two lane road at over 8000 and it was definitely not as responsive. But I did discover that despite a seemingly higher VTEC engagement point, that VTEC still helps alot up there since most other cars has the same lack of oxygen problem as I did. SO, I just drove around at 5800-6500rpm as a prepared to pass folks.

 

Higher altitude will hurt all cars, even turbo'ed/supercharged engines. There was an epic technology war during World War II between the combatants over airplane piston engines. Basically, the side that could field airplanes that could get the most power at high altitudes (20,000-30,000ft or higher, about 4-6 times the altitude of Denver) had a big advantage. The US and British ended up winning that war The advent of turbo-supercharged airplanes for the Americans (P47, B17, B24, B29) made a big difference.

My point is that piston engines have always suffered at atlitude The air at Denver is about 85% as dense as at sea level (meaning a 240hp NA engine at sea level would get only ~205hp at Denver). On I-70, west of Denver, the freeway tunnel is above 11,000ft at one end. Air is only about 65% dense at that altitude, meaning your 240hp engine generates about 156hp. Thus your S2000 engine turns into a Del Sol engine at the highest point on I-70

Last time I drove east to Denver, I found I had to downshift from 6th to 5th to maintain 70mph climbing that hill. I was quite impressed with my car's performance considering the altitude.

 

During the megameet drive up to Mt. Palomar, I noticed the lack of torque and power right away when going up the hills. Just shift to a lower gear and rev it more.

 

[QUOTE]Originally posted by hoof
[B]Last time I drove east to Denver, I found I had to downshift from 6th to 5th to maintain 70mph climbing that hill.

 

Steve C, I just made that same drive last week except mine took 23 hours. Only 20 hours on the way up there though. It's not too bad of a drive, lots of scenery. Elevation sucks...