FuelFacts

1999 Buick Regal MPG & Specs — Real-World vs EPA, All Trims

It depends on the trim. Some versions take premium and some take regular — check your exact engine/transmission below.

19–21
MPG combined (16–17 city / 25–27 hwy)
$2,714–$3,695
est. fuel / year (today's prices, 15k mi)
Varies by trim
gas type

Is the 1999 Buick Regal good on gas?

At up to 21 MPG combined, the 1999 Buick Regal is worse than average for a Midsize Cars — that class averages about 23.0 MPG across 5,710 EPA-tested versions, so it's on the thirsty side for its size.

Real-world MPG vs the EPA number

The EPA figures above come from a standardized dynamometer test, not the open road — real-world MPG typically runs a bit lower depending on your driving, climate and terrain. That's true of every car on this site, old or new.

This 1999 model was originally EPA-tested under the pre-2008 2-cycle method, which didn't account for highway speeds over 60 mph, air-conditioner use, or cold starts. When EPA overhauled the test for model year 2008, city ratings fell by about 12% and highway by about 8% on average industry-wide — and EPA retroactively adjusted every 1984-2007 rating to the stricter standard so old and new cars could be compared fairly. The MPG above is already on that modern scale — the window sticker on this car when it was new likely showed a higher, pre-2008-method number.

At today's AAA national average price — $3.80/gal for regular gas as of 2026-07-05 — the most efficient trim runs about $2,714/year (roughly $226/month, about $18.10 per 100 miles) at the EPA's assumed 15,000 miles/year, using an estimated 714 gallons a year. We don't estimate a cost-per-fill since exact tank size isn't in the public EPA dataset, but the per-100-mile figure scales to any tank. Current national average gas prices →

1999 Buick Regal trims & fuel economy

Trim (engine / transmission)FuelMPGFuel/yr (today's price)
3.8L 6-cyl, Automatic 4-spd, FWDREGULAR21$2,714
3.8L 6-cyl, Automatic 4-spd, FWDPREMIUM19$3,695
Where the EPA lists premium, that’s the fuel the maker specified for the mileage test — many such engines run on regular with slightly less power/MPG. Whether premium is required or just recommended is an owner’s-manual detail the EPA dataset omits, so we don’t guess it.

1999 Buick Regal specs

What the EPA test-car listings record for this model year — every combination sold is a row in the trims table above.

Engine options3.8L 6-cyl · 3.8L 6-cyl supercharged
TransmissionAutomatic 4-spd
Drive typeFWD
EPA body classMidsize Cars
FuelVaries by trim

Other years of the Buick Regal

2004 Buick Regal2003 Buick Regal2002 Buick Regal2001 Buick Regal2000 Buick Regal1998 Buick Regal1996 Buick Regal1995 Buick Regal

Similar cars (Midsize Cars)

1999 Mercedes-Benz E300 Turbodiesel1999 Oldsmobile Cutlass1999 Mercedes-Benz E320 Sedan1999 Mercedes-Benz E320 Sedan 4Matic1999 Ford Taurus1999 Buick Riviera

Cars that take premium · Cheapest cars to fuel · Where fuel grade depends on the trim · Fuel guides

2 trim(s) · EPA FuelEconomy.gov data retrieved 2026-07-24 · fuel prices AAA national average as of 2026-07-05.