2021 Roush Performance Mustang MPG and Fuel Economy

On this page, you will find a complete guide to the miles per gallon and fuel efficiency data for the 2021 Roush Performance Mustang.

The 2021 Roush Performance Mustang has 2 model options: Manual 6-spd 8-cyl, 5.0 L and Automatic (S10) 8-cyl, 5.0 L.

The 2021 Roush Performance Mustang Manual 6-spd 8-cyl, 5.0 L runs on premium gasoline and is in the Subcompact Cars car class.

The 2021 Roush Performance Mustang Automatic (S10) 8-cyl, 5.0 L runs on premium gasoline and is in the Subcompact Cars car class.

🛣 How Many Miles per Gallon (MPG) Does a 2021 Roush Performance Mustang Get?

Across all models, the combined average MPG for the 2021 Roush Performance Mustang is 15 miles per gallon.

The table below breaks down the MPG for each model option:

Model OptionCombined MPGCity MPGHighway MPG
Manual 6-spd 8-cyl, 5.0 L141219
Automatic (S10) 8-cyl, 5.0 L151219

💵 What is the Average Yearly Fuel Cost for a 2021 Roush Performance Mustang?

The average fuel costs for all models of the 2021 Roush Performance Mustang is $5,125.

The average fuel costs have been estimated by government regulators based on 15,000 miles driven per year, using regular gasoline, and a split of 55% city driving and 45% highway driving.

Comparing a 2021 Roush Performance Mustang to an average vehicle over 5 years, you will spend $14,125 more on fuel.

The table below shows the fuel costs and 5-year save/spend for each model option:

Model OptionFuel Cost5-Year Save/Spend
Manual 6-spd 8-cyl, 5.0 L$5,300spend $15,000 more
Automatic (S10) 8-cyl, 5.0 L$4,950spend $13,250 more

The 2021 Roush Performance Mustang is also subject to the Gas Guzzler Tax, which is a federal tax on vehicles that has a combined MPG of less than 22.5.

The tables below show how much you can expect to pay in Gas Guzzler taxes.

Model OptionGas Guzzler Tax
Manual 6-spd 8-cyl, 5.0 L$5,400
Model OptionGas Guzzler Tax
Automatic (S10) 8-cyl, 5.0 L$4,500

🛢 How Many Barrels of Petroleum Does a 2021 Roush Performance Mustang Consume?

Across all models, the average number barrels of petroleum that the 2021 Roush Performance Mustang will consume in one year is 21 barrels.

The majority of the world's petroleum is sourced from countries like Saudi Arabia, Russia, Iraq, and the United States.

Model OptionBarrels
Manual 6-spd 8-cyl, 5.0 L21
Automatic (S10) 8-cyl, 5.0 L20

💨 How Many Grams of CO2 Does a 2021 Roush Performance Mustang Emit?

The 2021 Roush Performance Mustang will emit an average of about 9,180,000 grams of CO2 per year.

🌳 To help you understand the impact of this, a normal tree will absorb around 21,000 grams of CO2 per year. This means that roughly 313 trees would be needed to offset emissions from the 2021 Roush Performance Mustang.

Overview

The tables below cover all of the miles per gallon, engine specifications, and emission details we have for the 2 2021 Roush Performance Mustang model options.

Manual 6-spd 8-cyl, 5.0 L

The table below contains all of the details we have for the 2021 Roush Performance Mustang Manual 6-spd 8-cyl, 5.0 L:

City MPG12
Highway MPG19
Combined MPG14
Save/Spend vs Average CarSpend $15,000
Gas Guzzler Tax$5,400
Fuel Cost$5,300
Fuel Type 1Premium
Barrels of Petroleum21
Grams of CO29,270,000
Trees Needed to Offset441
DriveRear-Wheel Drive
Cylinders8
Displacement5
TransmissionManual 6-spd
Vehicle ClassSubcompact Cars
Start/Stop?No
Supercharged?Yes
Turbocharged?No

Automatic (S10) 8-cyl, 5.0 L

The table below contains all of the details we have for the 2021 Roush Performance Mustang Automatic (S10) 8-cyl, 5.0 L:

City MPG12
Highway MPG19
Combined MPG15
Save/Spend vs Average CarSpend $13,250
Gas Guzzler Tax$4,500
Fuel Cost$4,950
Fuel Type 1Premium
Barrels of Petroleum20
Grams of CO29,090,000
Trees Needed to Offset433
DriveRear-Wheel Drive
Cylinders8
Displacement5
TransmissionAutomatic (S10)
Vehicle ClassSubcompact Cars
Start/Stop?No
Supercharged?Yes
Turbocharged?No

Link To or Reference This Page

If you use this page in your research, please reference MPG Buddy as the source.

  • "2021 Roush Performance Mustang MPG and Fuel Economy." MPG Buddy. Accessed on January 3, 2026. https://mpgbuddy.com/cars/roush-performance/mustang/2021.

  • "2021 Roush Performance Mustang MPG and Fuel Economy." MPG Buddy, https://mpgbuddy.com/cars/roush-performance/mustang/2021. Accessed January 3, 2026.

  • 2021 Roush Performance Mustang MPG and Fuel Economy. MPG Buddy. Retrieved from https://mpgbuddy.com/cars/roush-performance/mustang/2021.