What AWD and 4WD do to an EPA rating

Comparing 4,863 pairs of versions that share a nameplate, model year and engine, the all-wheel-drive or four-wheel-drive version rated a median 1 MPG lower than the two-wheel-drive version, or 5.0%. The penalty has shrunk over time, from 6.2% in 1984–1999 to 4.3% in 2020–2026, and in 24.9% of pairs there was none at all.

How the pairs were built

A pair is two conventional gasoline versions of the same nameplate in the same model year with the same engine displacement: the best two-wheel-drive version and the best all-wheel or four-wheel-drive version. Keeping the engine fixed leaves the drive system as the main difference between the two versions. Hybrids, diesels and electric versions are left out. Counts on this page are of versions or nameplates EPA rated, not of vehicles sold, so nothing here is weighted by sales.

The typical penalty

The median difference is 1 MPG, or 5.0% of the two-wheel-drive rating. On a vehicle rated 25 MPG with front-wheel drive, that points to about 24 MPG with all-wheel drive. EPA rounds every rating to a whole number, so many small differences show up as either 0 or 1 MPG, and the median in MPG is exactly one.

About a quarter of pairs, 24.9%, showed no difference at all after rounding.

By vehicle family

Family	Pairs	Median MPG	Median %
Minivans	52	2	9.1%
Vans	117	1	6.2%
Pickups	951	1	5.9%
Special purpose vehicles	302	1	5.6%
Station wagons	222	1	5.0%
Cars	1,265	1	4.8%
SUVs	1,954	1	4.5%

Minivans show the largest median penalty, 9.1%, but from only 52 pairs. SUVs, with 1,954 pairs the largest group by far, show 4.5%, slightly less than cars at 4.8%. Pickups sit at 5.9% and vans at 6.2%.

In MPG terms the percentages are small. A pickup rated 20 MPG with two-wheel drive and a median 5.9% penalty would land near 18.8 MPG with four-wheel drive; a car rated 30 MPG with a 4.8% penalty, near 28.6. Rounded to whole numbers on EPA's labels, both show up as a one or two MPG gap.

Restricted to model years 2020–2026, the family medians are 4.3% for SUVs (521 pairs), 4.5% for cars (302 pairs) and 4.9% for pickups (124 pairs).

What the comparison leaves out

Only nameplates that EPA rated with both kinds of drive and the same engine size in the same year enter the comparison. Models offered with all-wheel drive alone, or with a larger engine only in their all-wheel-drive versions, have no pair and are not counted. Diesel, hybrid and electric versions are left out entirely. And these are label ratings: they say how EPA's tests rate each version, not how much fuel a particular vehicle uses in snow, mud or towing.

Over time

Model years	Pairs	Median MPG	Median %
1984–1999	961	1	6.2%
2000–2009	1,328	1	5.3%
2010–2019	1,577	1	4.8%
2020–2026	997	1	4.3%

The penalty has fallen in every period: 6.2% for 1984–1999, 5.3% for 2000–2009, 4.8% for 2010–2019 and 4.3% for 2020–2026. In MPG the median stays at one throughout, while the ratings themselves rose.

Where the pairs come from

SUVs provide 1,954 of the 4,863 pairs, 40.2%, and cars 1,265, or 26.0%. Pickups follow with 951. The number of pairs per period also rose, from 961 in the sixteen model years of 1984–1999 to 1,577 in the ten years of 2010–2019. In 25 pairs the all-wheel-drive version actually rated higher than the two-wheel-drive version with the same engine.

How large the gaps get

Nearly half of all pairs, 49.1%, differ by exactly one MPG. Larger gaps are rare: 4.9% of pairs show three MPG and 2.2% four or more.

Penalty	Pairs	Share
No difference or AWD higher	1,209	24.9%
1 MPG	2,388	49.1%
2 MPG	923	19.0%
3 MPG	236	4.9%
4 MPG or more	107	2.2%

Model year 2026

For 2026 there are 92 pairs. Their median penalty is 1 MPG, and 16.3% of them show no difference. The largest gaps that year, one per nameplate, are listed below; all of them have engines of 2.5 liters or less. The Hyundai Sonata with the 2.5-liter engine shows the largest, 32 MPG with two-wheel drive against 27 with all-wheel drive, a difference of 5 MPG.

Nameplate	Engine	2WD	AWD/4WD
Hyundai Sonata	2.5 L	32 MPG	27 MPG
Chevrolet Trailblazer	1.3 L	31 MPG	27 MPG
Volkswagen Tiguan	2.0 L	29 MPG	25 MPG
Buick Encore	1.3 L	30 MPG	27 MPG
Hyundai Kona	2.0 L	31 MPG	28 MPG
Kia K5	2.5 L	30 MPG	27 MPG
Volkswagen Taos	1.5 L	31 MPG	28 MPG
Cadillac CT5	2.0 L	26 MPG	24 MPG

Using these numbers

In gallons the gap is easier to picture. At 15,000 miles a year, the Hyundai Sonata pair above works out to 468.8 gallons with two-wheel drive and 555.6 with all-wheel drive, a difference of 86.8 gallons. A one MPG gap on a vehicle rated near 25 MPG comes to roughly 25 gallons a year at that mileage.

For a specific model the answer is in its year table: the Subaru Forester or Toyota RAV4 pages list the best and lowest version for each year, and the gallons calculator can put the two-wheel-drive and all-wheel-drive versions of one model side by side at your own mileage.