Part of the data ring
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Two sheets, one bench · Midsize-Large Station Wagons

Century Wagon vs Summit Wagon

Buick Century Wagon against Eagle Summit Wagon, two test sheets laid side by side.

Buick Century Wagon

21
MPG · $2286/yr
More efficient
vs

Eagle Summit Wagon

21
MPG · $2286/yr

The gap, in fuel

$0a year between them

The Buick Century Wagon is more efficient — 21 MPG against 21 for the Eagle Summit Wagon. Over 15,000 miles a year at $3.20 a gallon that is a saving of about $0 a year, or $0 over five years.

SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026

How this is worked out

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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 →

Both sheets, line for line

Buick Century WagonEagle Summit Wagon
Combined economy 21 21
Best year on record 26 23
Worst year on record 17 18
Average across all years 20.4 20.9
Fuel per year 2286 2286
Gallons per year 714 714
CO₂ g/mi 423 427
Model years tracked 12 5
ClassMidsize-Large Station WagonsMidsize-Large Station Wagons
Years1985–19961992–1996

Highlighted cells are the better of the two on that measure. Fuel costs at $3.20/gal over 15,000 miles.

SOURCE·US EPA fuel-economy test data·FUEL ASSUMED AT $3.20/GAL FROM JUL 2026·REVIEWED JUL 2026

Questions asked across the counter

Which is more fuel efficient, the Buick Century Wagon or the Eagle Summit Wagon?

The Buick Century Wagon is more efficient — 21 MPG against 21 for the Eagle Summit Wagon. Over 15,000 miles a year at $3.20 a gallon that is a saving of about $0 a year, or $0 over five years.

Which is cheaper to run, the Buick Century Wagon or the Eagle Summit Wagon?

On fuel alone, the Buick Century Wagon: $2286 a year against $2286 for the Eagle Summit Wagon, both at $3.20 a gallon over 15,000 miles — an assumption fixed JUL 2026. Fuel is the only line being compared: depreciation, insurance, tyres and servicing are not in it, and they routinely matter more than this gap.

Is the difference big enough to change the decision?

Across five years of that same driving the gap comes to about $0. That is real money, and it is also roughly what one year of depreciation does to a new car — so treat it as one line in the ledger rather than the whole argument.

Both entries carry the full year-by-year history and the pump-price ledger. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.

See all 10 sites in this family, with what each one answers

Published by

Amit Sharma

Auckland real-estate agent and marketer. Builds free, sourced data tools.