Bertone X1/9
What it costs to keep fuelled
$2,182a year, fuel only
The 1989 Bertone X1/9 is EPA-rated at 22 MPG combined (20 city / 26 highway). Over 15,000 miles a year that is about 682 gallons, $2182 a year in fuel, or $0.145 per mile at $3.20/gal.
Across its full 1984–1989 run it averages 22 MPG, essentially flat across 6 model years.
The band is how far one gallon carries it: 22 of the 60 MPG this scale runs to. The square tick is the two seaters average, 21.4.
- Fuel, per year
- $2,182 at 15,000 mi
- Per mile
- $0.145
- Per kilometre
- $0.090
- Gallons burned/yr
- 682
1 mile = 1.609344 km · fuel at $3.20/gal, fixed JUL 2026
Test figure — not a road resultSOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
How this is worked out
- Start from the EPA combined figure for the model year — a laboratory test cycle run to a fixed procedure, not a road result. Where a year sold several engines or drivetrains, the trims are averaged and the trim count is printed beside the row so you can see how much averaging is behind it.
- Fix a pump price. This site keeps one reference price, $3.20 a US gallon, fixed JUL 2026 and printed next to every dollar figure it produces. It is an assumption with a date on it, not a quote — put your own price in.
- Fix an annual distance. Every annual figure on this site uses 15,000 miles a year, roughly the US average. A cost per year with no stated distance is not a number, it is a mood.
- Divide distance by economy for gallons, multiply by price for the year's fuel, divide price by economy for one mile. The per-kilometre line is that last figure divided by 1.609344 — the same money, in the unit most of the world drives in.
- Stop there. No depreciation, no tyres, no insurance, no servicing. This is the fuel line of the ledger and it is labelled as one; depreciation usually dwarfs everything on it.
gallons/yr = miles/yr ÷ MPG fuel $/yr = gallons/yr × $/gal cost $/mi = $/gal ÷ MPG cost $/km = cost $/mi ÷ 1.609344
The full method, the licence note, and what a test figure cannot tell you →
Re-run the ledger at another pump price
Every line above rests on one pump price. Here is the same entry re-costed at six others, because the price is the part that changes while the test sheet stays put.
| Fuel price | Per mile | 10,000 mi/yr | 15,000 mi/yr | 20,000 mi/yr |
|---|---|---|---|---|
| $2.50/gal | $0.114 | $1136 | $1705 | $2273 |
| $3.00/gal | $0.136 | $1364 | $2045 | $2727 |
| $3.20/gal | $0.145 | $1455 | $2182 | $2909 |
| $3.50/gal | $0.159 | $1591 | $2386 | $3182 |
| $4.00/gal | $0.182 | $1818 | $2727 | $3636 |
| $4.50/gal | $0.205 | $2045 | $3068 | $4091 |
| $5.00/gal | $0.227 | $2273 | $3409 | $4545 |
SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
The whole service history, sheet by sheet
6 model years on file. Read down the combined column: a nameplate that got heavier shows it here long before any brochure admits it.
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 1989 | 22 MPG | 20 | 26 | $2850 | 404 | 1 |
| 1988 | 22 MPG | 20 | 26 | $2850 | 404 | 1 |
| 1987 | 22 MPG | 20 | 26 | $2850 | 404 | 1 |
| 1986 | 22 MPG | 20 | 26 | $2850 | 404 | 1 |
| 1985 | 22 MPG | 20 | 26 | $2850 | 404 | 1 |
| 1984 | 22 MPG | 20 | 26 | $2850 | 404 | 2 |
Where a model year offered several engines or drivetrains, the figure is the average across all EPA-tested trims that year — the trim count is shown so you can see how much averaging is involved.
SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
Marked against the rest of the two seaters bay
Among the 105 two seaters models tracked here, the Bertone X1/9 ranks 28 on current figures, against a class average of 21.4 MPG — the square tick on the gauge above.
Closest more-efficient alternatives in the same class: Lotus Elise/Exige (22.5), Porsche 718 Boxster (23), Porsche 718 Cayman (23), Porsche Boxster (23), Porsche Cayman (23).
Tailpipe CO₂ is rated at 404 grams per mile, which works out to roughly 6.1 tonnes a year at 15,000 miles.
Questions asked across the counter
What MPG does the Bertone X1/9 get?
The 1989 Bertone X1/9 is rated at 22 MPG combined by the EPA — 20 city and 26 highway. Across all 6 model years in the database it averages 22 MPG, ranging from 22 to 22 depending on year and trim.
How much does a Bertone X1/9 cost in fuel per year?
At 22 MPG and 15,000 miles a year, it burns about 682 gallons — roughly $2182 a year with fuel at $3.20 a gallon, or $0.145 per mile. The EPA's own published annual figure for the 1989 model is $2850.
Has the Bertone X1/9 become more efficient over time?
Barely. It sits at 22 MPG today against 22 in 1984 — essentially flat across 6 model years, with efficiency gains offset by weight and power creep.
Is the Bertone X1/9 efficient for its class?
It ranks 28 of 105 in the Two Seaters class on current figures, against a class average of 21.4 MPG. That is 0.6 better than typical for the class.
Pull another logbook off the same shelf
Same class, nearest economy first — the ones a buyer is genuinely choosing between.
SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026
Cost per mile, per kilometre and per year are computed at a reference price of $3.20 a gallon over 15,000 miles, fixed JUL 2026 — set your own pump price. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.
