FuelFacts

← all 2003 GMC Sierra Denali 1500 AWD trims

2003 GMC Sierra Denali 1500 AWD — 6.0L 8-cyl, Automatic 4-spd, AWD

This 2003 GMC Sierra Denali 1500 AWD (6.0L 8-cyl, Automatic 4-spd, AWD) takes regular (87-octane) gasoline. REGULAR

13
MPG combined (11 city / 15 hwy)
$4,385
est. fuel cost / year (today’s prices, 15k mi)
tailpipe CO₂

At today's AAA national average price ($3.80/gal, 2026-07-05) — the EPA's own price/date assumption isn't exposed in the public dataset, so we recompute this from the EPA's MPG figure and a sourced current price.

This 2003 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.

EPA fuel type: Regular · class: Standard Pickup Trucks 4WD · engine: 6.0L 8-cyl · transmission: Automatic 4-spd · drive: AWD · MPG retrieved 2026-07-24.