I have a 44 mile round trip commute to work. On a full charge on a sunny day, I can make it back home with an estimated EV range of between 10 and 12 miles remaining. I’ve been doing this for about six weeks and that is pretty constant. Here in LA we don’t have cold temperatures to affect EV range but I’ve noticed now on three separate occasions how severely my EV range drops when it rains. Today I drove to work and it was dry but it was raining quite hard on the way home so only half of my commute was affected. But by the time I got home my estimated EV range was only 4 miles, so a trip of 22 miles in the rain dropped my fully charged EV range by more than 10%. A few weeks ago on a full charge I drove home from my mothers house in the rain and although it is only about 35 miles my charge was gone by the time I got home. On both occasions I was using the wipers and also the defroster for a while but not the whole trip. Is it just the increased rolling resistance of the wet highway and the rain hitting the car that reduces the mileage? I don’t know but I have been surprised by how much the rain affects my clarity.
Are you running the defrost to keep windows clear? If you don’t babysit it it’s possible to be running BOTH the resistive heater AND the air conditioner compressor to warm and dry the air. That will make your EV range take a huge hit. Also water on the road does increase rolling resistance. I’ll try and find an article on that and update my post. “At speed of 30 km/h, the increase of rolling resistance coefficient Cr is well correlated with the water film thickness. For 0.8-mm thick water film, the value of Cr is at about 30%, higher than for dry conditions. At higher speeds, the increase of Cr due to water film is more rapid, and the increase of 40% is reached already for water film thickness of 0.3 mm. For thicker water films, the rolling resistance coefficient stabilizes. It must be mentioned, however, that water film thickness of 0.8 mm, even at speed of 80 km/h, was not enough to cause aquaplaning.” http://www.davidpublisher.org/Public/uploads/Contribute/566e64a472e9f.pdf
Good point about the defrost but I frequently use the defrost in the morning for about 5 minutes to clear things up on non rainy days, about the same amount I used yesterday in the rain. The only other variable is the wet road and the rain itself as far as I can tell. And since this is LA even a hard rain is nothing like the kind of rain people get in other places of the country, but every time I've been in a hard rain and driving at freeway speed with my Clarity I've wished for a faster wiper speed, the max seems like it should be medium. I think I would feel blind if I was driving on the freeway in the truly hard rain I've experienced in the midwest or east coast.
My process for keeping things clear here in Texas when it’s not too cold: turn on climate, push climate button, tap off under ac settings, turn temp to LO, tap to set air mix to Defrost/feet, set intake to outside air and adjust fan as needed. This should prevent both the electric heat AND the A/C from running and might be enough to keep the windows clear with minimum usage of energy. For rain I’ve applied rain-x and it has helped keep the window clear enough that if it wasn’t for the road spray hanging in the air I’d be fine most of the time. I tried the rain-x anti fog and it just smeared up my window horribly and made everything worse.
I've noticed anecdotally that EV range falls somewhat in the rain, and I've also attributed it to increased rolling resistance. New tires can also mimic this effect.
