Idaho vs Oregon gas prices
Regular gas is $0.34 a gallon cheaper in Idaho — $5.05 on a 15-gallon fill-up. The two share a border, so that gap is worth knowing before you cross it.
Idaho
Oregon| Grade | ID | OR | Diff. | |
|---|---|---|---|---|
| Regular | $4.31 | $4.65 | $0.34ID | Idaho |
| Midgrade | $4.60 | $4.91 | $0.31ID | Idaho |
| Premium | $4.87 | $5.20 | $0.33ID | Idaho |
| Diesel | $5.32 | $5.52 | $0.21ID | Idaho |
Where the $0.34 gap actually comes from
21% of it is tax. Oregon charges $0.07 more per gallon in federal and state taxes than Idaho. The remaining $0.27 is a real difference in what the fuel, refining and distribution cost — refinery proximity, pipeline access and state fuel-blend rules.
Fuel, refining, distribution and marginFederal and state taxes Pre-tax figures are estimates — see the note below.
What the gap is worth
Based on today’s $0.34 per-gallon difference, which moves week to week. Use the fuel cost calculator for your own mileage and vehicle.
Prices by metro area
State averages hide a lot. These are the cheapest metros AAA reports on each side.
Other comparisons
Frequently asked questions
Is gas cheaper in Idaho or Oregon?
Regular gas is cheaper in Idaho, at $4.31 a gallon against $4.65 in Oregon — a gap of $0.34, or 7.8%. On a 15-gallon fill-up that is $5.05. Figures are AAA daily state averages for 2026-08-02.
Why is gas more expensive in Oregon?
21% of the $0.34 gap is tax rather than the cost of the fuel. Oregon levies $0.07 more per gallon in federal and state taxes; the remaining $0.27 is a genuine difference in what the fuel, refining and distribution cost.
Is diesel cheaper in Idaho or Oregon?
Diesel is cheaper in Idaho at $5.32 a gallon, against $5.52 in Oregon — $0.21 a gallon apart.
Is it worth crossing from Oregon into Idaho to fill up?
If you are already near the line, yes: a 15-gallon fill saves about $5.05. Driving out of your way for it rarely pays — at $4.65 a gallon and 25 mpg, a 14-mile round trip would eat the whole saving in fuel alone, before your time.