Everybody likes to talk about how electric cars like the Tesla Model 3 are much more cost-efficient to own compared to gasoline powered cars, especially when it comes to fuel costs. Comparing a Tesla Model 3 Performance to something like the Alfa Romeo Giulia Quadrifoglio, the cost savings seem significant.

In the latest video from Engineering Explained, Jason runs through some math comparing the fuel cost efficiency of his personal Tesla Model 3 Performance versus the Alfa Romeo Giulia Quadrifoglio, a vehicle of similar size, weight, performance and price.

The first comparison is simply how much it costs to “fill up” each car with the maximum amount of fuel. For the Model 3 Performance and its 75 kWh battery, in Jason’s case, it could cost $9.38 for a single fill up. Jason calculated the cost per kWh to be $0.10 based on his personal energy bill, and used a charging efficiency of 80 percent, which is likely a conservative estimate.

Charging efficiency is exactly how it reads—it’s how efficient the charging system is at feeding energy into the battery. Some energy that is sourced from the power supply is lost in the charging process. Charging a 75 kWh battery requires more than 75 kWh of energy from the source, and that difference determines the charging efficiency.

Tesla has not confirmed a specific number for the Model 3 Performance, so Jason used a conservative estimate of 80 percent efficiency, which would mean it would require 93.8 kWh of energy to fully charge the 75 kWh battery pack.

The cost to fill up the tank on the Giulia Quadrifoglio, using an estimated average cost of $3 per gallon of premium gas, would cost $45.90, or about $36.52 more per fill up.

If Jason were to drive these cars 1,000 miles a month, the monthly cost of fuel for the Model 3 Performance would be around $30, and the annual cost would be around $363. The Giulia Quadrifoglio would cost $150 per month using the EPA estimated 20 mpg combined for the car over the same 1,000 miles, and around $1,800 in fuel costs per year.

According to Jason’s rough, conservative calculations, not taking into account various possible driving conditions and driving styles, you would save about $1,400 per year driving the Model 3 Performance. The EPA estimates that annual fuel costs would be $550 for the Model 3 Performance and $2,250 for the Giulia Quadrifoglio, which would be a difference of about $1,600 annually.

The greatest lesson to take away here is just how efficient electric cars are at using electric power for fuel. To show this, Jason also calculated what the fuel costs for the Quadrifoglio would be if the car’s combustion engine was as fuel efficient as the Model 3.

If the Quadrifoglio actually got 116 mpg, which is the EPA estimate for the Model 3 Performance, it would only be about $310 per year in fuel costs. That’s better than the Model 3 Performance, but only if premium gasoline held steady at $3 per gallon.

So there you have it. While this was in no way a truly scientific exploration, it sure had a lot of convincing math and seemingly-solid estimates to provide a rough idea of just how fuel efficient electric cars are compared to their combustion counterparts.