1984 AM General FJ8c Post Office: MPG and fuel economy
The 1984 AM General FJ8c Post Office is rated by the U.S. Environmental Protection Agency at 13 combined MPG, with 13 MPG in the city and 13 MPG on the highway. That lands well below the average for cars in the Special Purpose Vehicle 2WD class in the same model year.
This page collects every fuel-economy figure the EPA publishes for the 1984 AM General FJ8c Post Office. Below you will find the headline combined, city, and highway MPG, the estimated annual fuel cost at three different driving levels, the tailpipe CO₂ emissions, and a full breakdown of the engine and drivetrain. The EPA rates 2 separate variants of this car (different engine, transmission, or drivetrain combinations), and you can compare them side by side in the trims table.
Key takeaways
- Returns 21% worse combined MPG than the average car in the Special Purpose Vehicle 2WD class for the 1984 model year (16.5 MPG class average).
- The most efficient car in the Special Purpose Vehicle 2WD class for the 1984 model year is the Grumman Olson Kubvan at 27 MPG.
- EPA estimates this car costs around $12,250 more in fuel over five years than an average new vehicle of the same model year.
Fuel economy at a glance
These are the EPA's official ratings for the 1984 AM General FJ8c Post Office. The numbers come from a standardised laboratory test cycle and are the same figures that appear on the window sticker of every new car. Real-world mileage varies with driving style, weather, fuel quality, and how heavily loaded the car is.
When the EPA tests several variants of the same nameplate (for example, a front-wheel-drive version and an all-wheel-drive version), each gets its own rating. The figures shown here are the headline variant, taken as the configuration with the best combined MPG. The trims table further down covers all 2 variants side by side.
Combined MPG is a 55/45 weighted blend of the city and highway test cycles. The EPA uses it as the single number you can compare across the entire dataset, including hybrids and EVs (which use the equivalent MPGe figure).
| Combined MPG | 13 MPG |
| City MPG | 13 MPG |
| Highway MPG | 13 MPG |
| Annual fuel cost | $4,600 |
| Tailpipe CO₂ | 684 g/mi |
| Fuel type | Regular |
How the 1984 AM General FJ8c Post Office compares
The 1984 AM General FJ8c Post Office returns 13 combined MPG. Cars in the Special Purpose Vehicle 2WD class for the same model year average 16.5 MPG, which puts this car behind the class average by about 21%.
The most efficient car in the Special Purpose Vehicle 2WD class for the 1984 model year is the Grumman Olson Kubvan at 27 MPG. The bar chart below puts the AM General FJ8c Post Office alongside the class best and the class average so you can see the full picture.
For broader context, the average new car of the 1984 model year (across all classes) returns 19.2 MPG. Larger vehicles pull the all-cars average down, so do not use that figure on its own to judge a small car or a hybrid. The full list of the most efficient cars of the 1984 model year is on its own page.
Trim variants rated for 1984
The EPA rates 2 separate variants of the 1984 AM General FJ8c Post Office. The differences come from the engine size, transmission type, and drivetrain (front-wheel drive, all-wheel drive, and so on). The same nameplate can land several MPG apart depending on the configuration you actually buy.
| Engine and transmission | Drive | Combined | City | Highway | Annual cost |
|---|---|---|---|---|---|
| 4.2L, 6-cyl, Automatic 3-spd | 2-Wheel Drive | 13 MPG | 13 MPG | 13 MPG | $4,600 |
| 4.2L, 6-cyl, Automatic 3-spd | 2-Wheel Drive | 13 MPG | 13 MPG | 13 MPG | $4,600 |
Annual fuel cost across driving patterns
The headline annual fuel cost the EPA publishes assumes 15,000 miles of driving per year and a fuel mix of 55% city and 45% highway. The dollar figure is calculated using the EPA's current reference price for regular gasoline, which is $3.99/gallon. EPA updates that reference periodically rather than tracking live pump prices, so treat it as a window-sticker estimate rather than today's pump number.
The table below scales the EPA's number to three common driving patterns. The combined MPG and the reference fuel price stay constant, only the annual mileage changes. To get a current-prices estimate, take your local gas price and multiply by 1153.8 gallons (the car's annual consumption at the rated MPG).
| Driving pattern | Estimated annual fuel cost |
|---|---|
| Light driver, 7,500 miles per year | $2,300 |
| Average driver, 15,000 miles per year | $4,600 |
| Heavy driver, 25,000 miles per year | $7,667 |
Compare against other Special Purpose Vehicle 2WD for 1984
If you are cross-shopping the 1984 AM General FJ8c Post Office, the most useful comparison is against the other cars in the Special Purpose Vehicle 2WD class for the same model year. The list below shows the highest-MPG peers, ranked from most to least efficient. Click any of them to open its full page.
The Grumman Olson Kubvan leads this group at 31 MPG, 18 MPG ahead of the 1984 AM General FJ8c Post Office.
Specifications
The 1984 AM General FJ8c Post Office runs a 4.2-liter 6-cylinder engine paired with a automatic 3-spd, sending power through 2-wheel drive.
Engine, transmission, and drivetrain together drive most of the variation in fuel economy across trims. A larger engine moves the car with less effort but burns more fuel. A turbo lets a small engine punch above its weight, often without much MPG penalty. All-wheel drive adds traction and weight, and usually costs a couple of MPG compared with two-wheel drive of the same engine.
- Vehicle class
- Special Purpose Vehicle 2WD
- Engine
- 4.2L 6-cylinder
- Transmission
- Automatic 3-spd
- Drivetrain
- 2-Wheel Drive
- Fuel type
- Regular
- Annual petroleum use
- 22.9 barrels per year
Common questions about the 1984 AM General FJ8c Post Office
Quick answers to the questions people most often search for when looking up the 1984 AM General FJ8c Post Office.
-
Is the 1984 AM General FJ8c Post Office fuel efficient?
Not particularly. The 1984 AM General FJ8c Post Office returns 13 combined MPG, which trails the average car in the Special Purpose Vehicle 2WD class for the same model year by about 21%. -
What MPG does the 1984 AM General FJ8c Post Office get?
The EPA rates the 1984 AM General FJ8c Post Office at 13 combined MPG, 13 MPG in city driving, and 13 MPG on the highway. Real-world numbers depend on your driving style, the weather, and how loaded the car is. -
How much does it cost to fuel a 1984 AM General FJ8c Post Office per year?
The EPA estimates an annual fuel cost of $4,600 for the 1984 AM General FJ8c Post Office. That figure assumes 15,000 miles of driving per year, a 55% city and 45% highway split, and the EPA's published average fuel price for the rated fuel grade. -
What fuel does the 1984 AM General FJ8c Post Office use?
The EPA lists the 1984 AM General FJ8c Post Office as running on regular gasoline. Using a different grade than the manufacturer specifies can affect fuel economy and engine longevity. -
How much CO₂ does the 1984 AM General FJ8c Post Office emit?
Tailpipe CO₂ emissions are 684 g/mi. Multiplied across a typical year of driving (15,000 miles) that works out to about 10,254 kilograms of CO₂. -
What is the difference between the city and highway MPG of the 1984 AM General FJ8c Post Office?
City driving returns 13 MPG and highway driving returns 13 MPG. A flat (or city-better) split is the signature of a hybrid or electric drivetrain, where regenerative braking recovers energy that would otherwise be lost in stop-start city traffic. -
What engine is in the 1984 AM General FJ8c Post Office?
The 1984 AM General FJ8c Post Office has a 4.2-liter 6-cylinder engine (EPA description: (FFS)). -
What transmission and drivetrain does the 1984 AM General FJ8c Post Office have?
The 1984 AM General FJ8c Post Office comes with a automatic 3-spd transmission and 2-wheel drive. -
How does the 1984 AM General FJ8c Post Office compare to the best car in its class?
The most efficient car in the Special Purpose Vehicle 2WD class for the 1984 model year is the Grumman Olson Kubvan at 27 combined MPG. The AM General FJ8c Post Office returns 13 MPG, a gap of 14 MPG. If you are comparing on fuel economy alone, the class leader is worth a look. -
How much more does the 1984 AM General FJ8c Post Office cost in fuel compared to an average car?
The EPA estimates that over five years, the 1984 AM General FJ8c Post Office will cost about $12,250 more in fuel than an average new vehicle of the same model year. The difference accumulates because the car uses more fuel per mile, not because of any one-off charge at the dealership.
Source: U.S. EPA fuel economy dataset. Annual fuel cost figures assume 15,000 miles of driving per year and a 55% city, 45% highway split. Real-world mileage varies with driving conditions, vehicle maintenance, fuel quality, and driver behaviour.