Denver to Portland, OR - gradual climb

I will be driving from the East coast to Portland, OR soon, with my last scheduled stop in the Denver area. I have a very small car - 1L, 3cyl. It's a wonderful car overall, but with such little power, I would like to take a route which requires the most gradual continental divide climb, or a climb at a low elevation. This seems to be I80 N to Cheyenne to I84 W. I am also toying with going through Yellowstone as I've never been there, but it seems to lots more up-and-down through there. Any experiences?

Also, does anyone have experience in packing cars? I am wondering how much extra weight will affect performance/mileage. So, how many extra pounds would slow down my little engine that could? Last time I crossed the Rockies was in BC, Canada, in a slightly larger car and it struggled a little bit.

Welcome aboard the RoadTrip America Forums!

First, I hope you plan to stop somewhere between Denver and Portland. That's over 1,250 miles and far more than you should even be considering trying to drive in one sitting.

In general, the Interstates have the gentlest climbs. They are limited by design criteria to a grade of 6% or less, so you should probably stick to I-25/I-80/I-84 from Denver to Portland. You won't be able to keep up with most of the auto traffic, but you should be able to keep up with the trucks in the climbing lanes. For the record, my first car had a 0.5 liter, 3 cylinder engine and I used it for racing. You should also check your owners manual for what the carrying capacity of your car is. I'm sure it will be listed somewhere in there, and I'm sure it won't be much. How much loading your car will affect speed and gas mileage depends on a lot of factors, but none of them will cause either figure to go up. You'll just have to live with whatever performance you get.

AZBuck