Here's a site with lots of info on that area you are talking about.  Page
around and I am sure you can find somewhere on the Deathride site where each
pass's actual profile is given.  As I recall, Carson Pass is much less steep
than Ebbits Pass, but longer and more subject to possible headwinds.  There
really is no easy way over the Sierras, as the Donner Party learned long
ago..

http://www.deathride.com/maps.html

  Don Hanson

Date:    Wed, 23 Jul 2008 17:29:15 -0700
From:    Michael Hart <mjhart853@YAHOO.COM>
Subject:

I am planning a round trip loop through the Sierras in California starting
next week (starting from the San Francisco Bay Area)
The Sierras have gradual gradients going East, but coming back West is a
different story. Last year I took Highway 4 (Ebert's Pass) both ways (most
convenient for our planned destination), but the West direction is VERY
steep (25% for the last mile close to the summit), so I was down to 1st gear
in my fully loaded Westy (temperature gauge running at the high side on a
very hot day > 100F and strange sounds coming from the engine/transmission).
Also, the approach to Ebert's Pass from Highway 395 over Highway 89 (Monitor
Pass) was pretty steep too.
No apparent damage to the engine or transmission and since then I've had
VolksCafe completely rebuild the cooling system (new radiator, stainless
pipes, etc, etc.) [btw - great work by Peter at VolksCafe!], so I'm not too
worried about overheating, but I'd rather not stress the engine so much
again. Hence I will NOT be taking Ebert's Pass West again and need an
alternate route.

I've tried to find out the gradients of the other major passes, without
success.

So to my question - can someone tell me how steep Highway 88 (Carson Pass)
is going West from the Lake Tahoe area? (I've driven this before, but not
recently or in my Westy, you don't notice the hills quite so much in our
other car, a 2.8liter V6 VW Jetta...). Any other ideas for the 'least steep
pass' over the Sierras?

Thanks,
Mike
'87 Westy (stock 2.1l)
'97 Jetta GTX (2.8l VR6)
'00 Cabrio GLX