Boston Gas Edges Up to $4.142 as Diesel Climbs to $5.453

Boston’s latest AAA price check shows two different fuel trends: regular gas edged up only slightly, while diesel continued to rise more sharply. On July 31, 2026, the Boston (MA only) average was $4.142 per gallon for regular gas and $5.453 for diesel.

Regular gas was up $0.002 from the previous day, or two-tenths of a cent. That compares with a $0.016 increase from a week earlier, a $0.205 increase from a month earlier, and a $1.100 increase from the same check last year.

Gasoline is nearly flat day to day

The latest daily move is small for drivers filling up with regular gasoline. The Boston average rose from $4.140 on July 30 to $4.142 on July 31, according to AAA.

For commuters and households, the larger comparison is over time. A driver buying 15 gallons would pay about $3.08 more at the current Boston average than at the month-ago average, before accounting for station-by-station differences. Compared with a year ago, the same fill-up would cost about $16.50 more.

Those changes can affect commuting budgets, weekend travel and routine errands, but the effect will vary with vehicle efficiency, miles driven and how much fuel a household uses.

Diesel rises faster than regular gas

Diesel reached $5.453 per gallon in the July 31 Boston check, up $0.016 from $5.437 the previous day. The increase was larger across the other comparison periods: diesel was up $0.096 from a week ago, $0.269 from a month ago and $1.594 from a year ago.

That makes diesel the sharper-moving fuel in the latest Boston data. A 15-gallon diesel fill-up at the current average costs about $1.44 more than a week ago, about $4.04 more than a month ago and about $23.91 more than a year ago.

Higher diesel costs can create operating pressure for delivery drivers, contractors, maintenance companies, commercial fleets and other businesses that rely on diesel-powered vehicles or equipment. Those costs may be absorbed, passed through to customers or offset in other ways; the price data alone does not show how any particular business is responding.

Boston averages do not set every pump price

AAA’s figures are averages for the Boston (MA only) market, not guaranteed prices at every station. Actual pump prices can differ by neighborhood, station, brand, taxes, fuel grade and when the station’s price was last updated.

Boston 25 News reported on July 27 that Boston-area regular gas and diesel prices were already higher than a week and a year earlier, using AAA data. The newer July 31 AAA check shows regular gas almost unchanged from the prior day while diesel continues to post the larger short-term increase.

What are you seeing locally? Share the highest and lowest gas or diesel prices you have found at Boston-area pumps.

Sources

• AAA Fuel Prices — Massachusetts
• Boston 25 News — How gas prices have changed in Boston in the last week