A question about driving in mountians San Francisco to Lake Tahoe

A question about driving in mountians San Francisco to Lake Tahoe

This is sort of a general question. What is the difference in milage going up hill. There is a standard uphill pitch for highways or at least a median of sorts. So if you can go 200 miles on the flat how far would you be able to go up 7,000 feet. For instance, is it simply assumed that you would have to recharge going from San Franciso to Lake Tahoe somewhere along the way? I know there are public charging stations along the highway it would be good to not have to, is all.

Velo1 | April 18, 2013

I did some testing of this on my own in preparation for the Mt. Evans Road Rally on June 8th.

Here is my real-world test-drive data driving the first 10 miles from Idaho Springs to the 10-mile marker:

Start: elevation 7807 ft., my mileage range at 236.
At 10-mile marker: elevation 9807 ft., my mileage range at 210.
Returned to start: elevation 7807, my mileage range at 210.
The average grade is 6%.

So this drive was 10 miles up hill without any break in grade, and 10 miles straight back down.

I pretty much drove the speed limit 35-40 mph. Note that after the first 7 miles the road begins a series of switchbacks, with can be driven at 15-20 mph.

So in summary, on the ascent I used 2.6 miles of range per mile, and on the descent I did not use or lose any range. Not bad.

napacab | April 18, 2013

I have a similar question (I hope this is not hijacking your thread)

Will be on a road trip from San Francisco to San Diego next week in a P85.
Planning on stopping at Harris Ranch and Tejon Ranch on the way south.

Northbound I am wondering if driving from Del Mar to Tejon Ranch is doable?
It is only 186 miles but 4,000 feet of elevation will probably drop the range appreciably.

Any input would be helpful.

DouglasR | April 18, 2013

You need to add 8-10 miles per 1,000 feet of elevation gain on the way up. You will get around 70% of that back on the way down. Obviously, the actual number depends on a lot of other factors as well: speed, temperature, weather, use of accessories, load, etc.

I recently drove from Seattle to Mt. Rainier National Park, a distance of 121 miles each way, with 5,000' of elevation gain to the park. I used 160 rated miles on the way up, 86 rated miles on the return trip.

Take a look at the trip planner at I found it pretty accurate, although it underestimated the energy use on the way up and overestimated it on the way down. I'm not sure whether the formula has been tweaked since I used it.

EVTripPlanner | April 18, 2013

Here is the EV Trip Planner link for that route: (be sure to pick the correct model - 21" wheels cost you about 6% over 19"!)

We're still validating the algorithms, but it is usually pretty good. Any real-world data you can provide is appreciated. We're actually working on a "Tracker" that will log the data from your trips (it has to run on an internet-connected PC with Java while you're driving. You can download it from

@napacab - here is the Del Mar to Tejon route - should be OK for 19" wheels if you keep speed to 75 (and the calcs are correct!)

JackB | April 18, 2013

For an 85KWh Model S you only need to add 6 rated miles (or 7 ideal miles) per 1000' elevation gain, and usually you'll get over 90% of it back on the way down. Downhill driving is mainly about using less power (100% potential energy recovery) with a little bit of regen (64% recovery) thrown in on the steeper grades.


JackB | February 25, 2014

After weighing my car at a truck scale (it was 175 lbs heavier than I thought) and doing some weekend tests on the Mt Rose highway, a better rule of thumb is to assume 7 rated miles per 1000' elevation gain, and 6 rated miles of regen recovery per 1000' decline. While overall regen recovery is above 95% on the downhill (owing to the fact that recovery is 100% on the portion of potential energy that offsets the normal 10-15kW draw), the uphill inverter losses appear to be running 12-18%.

suratchai | February 25, 2014

I went 11,000+ Feet with 170 miles left on the pack and got up top to Big Bear Lake with 69 Miles

Brian H | February 26, 2014

Really? and how many linear road miles was that? Your post is meaningless.

Baribrotzer | February 26, 2014

According to the map, Big Bear Lake is about 30-35 miles from San Bernardino, which is the nearest low elevation area. So we get:

(11K ft.)(7 rated miles/ft) + 30 miles = 77 rated miles + 30 miles ~=~ 100 miles

Which sounds about like what suratchai got.

Brian H | February 26, 2014

Posters should not assume local knowledge. He doesn't give a clue as to his start point.

Codefiant | February 26, 2014

@Brian H -- You seem pretty angry. Ask nicely and the chances of getting a response will go up exponentially.

SCCRENDO.Ca.US | February 26, 2014

@codefiant That's Brian for you. Mostly offers grammar corrections and throws in some nastiness from time to time. Has a good theoretical knowledge of the car but last I heard is not yet an owner. So I would assume not much practical experience as yet.