I just finished a long road trip. Here are the numbers. 4489 km (2789 miles) 670 kWh used 149 Wh/km (240 Wh/mile) Total charging cost US $85.80 (had free destination chargers on 2 of the 4 nights) ¢1.91/km (¢3.08/mile) Road trip - Google My Maps I noticed a couple of quirks. The main one was that for some reason my first Supercharge in Canada in Cambridge, Ontario didn't autopay with my linked credit card. I had to manually use another credit card to pay it. I have no idea why still. Perhaps my main card rejected the transaction, but I didn't get a notice, so it seems unlikely. I also have 3 different numbers. First, the car says: My Tesla.com account history says: Cambridge, ON Supercharger 7/11/2018 12:47PM $4.00 Power Tier 2 10 min @ $0.40/min $4.00 Tax included $0.46 And finally my credit card was charged US $3.05 which I had to manually pay. So, although it doesn't specify the currency, it looks like the amount it lists on tesla.com is actually in CAD because $4 CAD is around US $3.05. The CAD $3.20 the car lists seems to be a guesstimate, or as others have mentioned, it is perhaps what the car thought it received, vs. what the Supercharger thought it sent. Looking at the cost differential across the states and the one province is interesting too. California: $0.26/kWh Nevada: Tier 1 $0.12/min, Tier 2 $0.24/min Utah: $0.22/kWh Wyoming: Tier 1 $0.11/min, Tier 2 $0.22/min Nebraska: Tier 1 $0.10/min, Tier 2 $0.20/min Iowa: Tier 1 $0.10/min, Tier 2 $0.20/min Illinois: $0.24/kWh Michigan: Tier 1 $0.12/min, Tier 2 $0.24/min Ontario: Tier 1 CA$0.20/min, Tier 2 CA$0.40/min Sometimes the tier 2 charging is a really good deal when you are pulling 115 kW, but it kind of sucks when you are only getting 61 kW.