Prime Premium 2018 Mileage

The 133 number is MPGe, note the "e" at the end. Do not drop the "e" as it means something different than mpg. 133mpge is the equivalent miles per gallon that the car will get in electric mode. Basically, if you're getting around 25 miles on a full charge, you're getting close to 133MPGe. (because based on the capacity of the battery, you get the advertised mileage to get the advertised range).

Hybrid mode is a separate rating.

Like @bisco said, Eco/Normal/Power is different from EV, HV and EV Auto.

Let's start with EV/HV/EV Auto. This controls the car's drivetrain state.

EV Mode: The default setting (assuming there is enough charge in the battery) is EV Mode. You can drive around solely on electric power for up to 25 miles (more or less depending on temperature, tire pressure, how you drive, the terrain of your commute etc etc). You can floor it and it will remain in EV mode and keep the engine off until the battery charge runs low. When that happens, it will switch to HV (hybrid) mode and operate like a regular Prius.

HV mode: This is hybrid mode. There are two ways to get here. 1) You can choose to go into HV mode at any time by pressing the EV/HV button. If there is charge left in the battery, this mode is similar to a "battery save" function. The hybrid system will still use a bit of battery but it will mostly remain intact. This is good if the first part of your trip involves highway driving and the latter or last part of your trip involves in-town driving. This allows you to use the gasoline engine efficiently at highway speed and save the battery charge for driving in EV mode when you're in-town. The reason you might want to do this is because your EV range will drop quickly at highway speeds. If you don't have a place to charge at your destination, then you may want to switch to HV first then EV later.

EV Auto: This setting tells the computer to choose the powertrain that matches your accelerator input, terrain and fuel efficiency. It will use electricity or engine depending on which it thinks is the most efficient at the time. I recently did a 25 mile trip in EV Auto and got to my destination with 3 miles left. The gas engine was on for a few of the uphill sections so that helped "extend" my EV range. So far, I've found it's best used for longer trips (near 25 miles or more) that aren't at highway speeds.

Drive Modes - Eco/Normal/Power

These control the accelerator pedal sensitivity, partially control the climate control system and possibly the engine as well.

Eco Mode: This is the least sensitive accelerator pedal setting. This allows for fine tuning of how much power you request through your right food. It allows to better control gliding and accelerating slowly to achieve excellent efficiency (both in electric and gas mode). If you select Eco mode from another mode, it will automatically turn on the "Eco Heat/Cool" setting for the climate control. This limits the maximum electricity consumption for the air conditioning compressor or heat pump to reduce energy consumption. Depending on the outside temperature, this also means it may take longer to heat or cool. Of course, you can manually control Eco Heat/Cool and have it on or off.

Normal mode: This is just the normal setting that Toyota wants for the vehicle. It blends efficiency and driving responsiveness. If your climate control was already in Eco Heat/Cool mode, it will retain that setting. If Eco Heat/Cool is off, it will not turn it on.

Power Mode: This makes the accelerator pedal super responsive and is meant for spirited driving. Based on the information for the regular Prius, this mode can also recognise your spirited driving and slightly adjust the drivetrain responsive to match your driving style. (Mostly the engine response).