One of the most talked about benefit of EV is the potential gas saving, but with gasoline price below its peak at 2012 most EV owners might not realize any significant saving. If you go to Tesla ordering page, it will give you an estimated saving of $5,500 over 5 years essentially $1000+ saving annually. Of course, you should review the fine print the gas saving is based on Mercedes S550 that get 21 miles per gallon requiring premium gas with 10% charging on the Supercharger network. Therefore, your gas saving is likely significantly lower if you are currently driving a fuel economy car.
Charging cost at home
Tesla does offer a cost estimator to charge your Tesla at home https://www.tesla.com/charge-at-home as you will notice it takes slightly more money and time to charge an Model X than Model S. Charging Model 3 would even be lower due to the new 2170 cells manufacture at the Gigafactory compare to the current 18650 cells in Model S and X. Tesla calculator assumes a 21 mpg and $2.7 per gallon price so if you are a non-luxury car owner the saving would be significantly less.
Installation cost
Currently all MS and MX come with a mobile charging connector bundle which mean you do not need to purchase an additional charging cable or install a charging station. If you live in an older home the chance is you will have to pay for an electrician to do some work. Ideally you will need a NEMA 14-50 240v with 50 AMP circuit breaker. It’s a good idea to get an estimate before you decide on ordering a Tesla, reported cost can range from hundreds to a couple thousand. Keep in mind, most local rebate for EV charging station don’t cover wiring and permit cost so if you are not buying a Tesla wall charger you will not be able to take advantage of the rebate.
Time of use (TOU) plan
Often time people will use time of use plan which offer significant savings if you charge your car in off-peak hours. Of course, there is a catch to it, your peak rate will go up. If you are at work during normal hours and come home to charge every night then it work great. But if you work at night and doesn’t come home until 8-9am in the morning to charge, then time of use plan likely will work against your favor. If you don’t drive a lot of miles or you charge at work or you do a lot of long distance trip that you need to supercharge then TOU could cost you more. To compare your current rate with TOU both PGE and SCE allow you to login to your account and see your rate under the TOU and regular plan. PGE (Pacific Gas and Electric Company) http://www.goo.gl/o0T3Q1 SCE (Southern California Edison) http://www.goo.gl/22rxVM
Charging efficiency
Despite Tesla having the most advance battery technology the battery still can’t defy physics. The charging process is not 100% efficient, its estimate the charging efficiency is somewhere between 80-90%, which mean you should add 10-20% of your charging cost. Some utility allows separating metering for EV charging, this will allow you to have greater transparency on the actual cost.
Vampire drain
If you don’t leave your Tesla plug in, you will notice every morning after you will lose 1-2% a day under normal weather condition. This is just like any other electrical appliances where it consumes power, even when not in use. So in a year, you will lose somewhere between 5-7 cycles of charge due to vampire drain.
Supercharging
You might think the best solution is to supercharge as it’s free (for those with free unlimited supercharging) and fast, then you don’t have to worry about the cost associated with TOU, vampire drain or charging efficiency. If you use the referral code http://ts.la/michael5707 you will receive 2000 miles of free supercharging. There are indeed drawbacks to supercharging, if you go to a Tesla service center (of course that’s after you already purchase your Tesla) they would tell you they are against the frequent use of supercharger as it can increase battery degradation. Also, there been owner posting their service report that Tesla will lower the charge rate (which prolong the charging time) if you frequently supercharge or fast charge with DC. So far this seems to only impact those with the 90kwh model and add only a few more minutes per charging session. Since supercharging network was not significantly expand until recent years. We will have to wait a few more years to get more data to determine the long term impact to battery degradation and charge speed especially in Model 3. So far most Model 3 owners reported almost no battery degradation.