Canadian motorists woke up to another reminder of how quickly fuel markets can reverse direction. In Ottawa, regular gasoline was forecast to climb seven cents a litre on September 12, effectively wiping out much of the sharp decline drivers had seen only a day earlier. On Prince Edward Island, the movement was far more severe: regulated diesel prices jumped by almost 18 cents a litre overnight, while furnace oil also became substantially more expensive.
The simultaneous changes came as global oil and refined-fuel markets faced renewed supply pressure, particularly for diesel. Crude prices remained above US$100 a barrel, international diesel supplies were exceptionally tight, and governments were increasingly confronting the uncomfortable reality that tax relief can soften a price shock without insulating consumers from global energy markets.
Ottawa’s One-Day Pump-Price Relief Disappears
Ottawa’s weekend increase was especially jarring because it came immediately after a substantial decline. Regular gasoline was forecast at 179.9 cents per litre on Friday, September 11, before rising seven cents to 186.9 cents per litre at 12:01 a.m. Saturday. For a driver purchasing 50 litres, that seven-cent reversal adds $3.50 to the bill overnight, taking the theoretical cost of that fill from $89.95 to $93.45. Individual stations can still charge differently because of local competition and inventory timing, so the regional forecast should not be interpreted as a mandatory citywide price.
The previous decline had been linked partly to the annual transition from more expensive summer-grade gasoline to winter fuel. Ottawa had been expected to see prices fall sharply on Friday as that seasonal change lowered wholesale costs. The relief proved brief. Wholesale fuel markets were already rebounding as geopolitical pressure, refinery conditions and rapidly changing petroleum prices overwhelmed some of the normal seasonal benefit. The result was classic price whiplash: a noticeable decrease followed almost immediately by a sizeable increase.
P.E.I.’s Diesel Increase Is Far More Severe
Prince Edward Island experienced an even more dramatic adjustment. The Island Regulatory and Appeals Commission announced an unscheduled petroleum-price interruption effective at 12:01 a.m. on Saturday, covering diesel and furnace oil. On September 11, the permitted self-serve diesel range had been 255.2 to 256.3 cents per litre. A day later, it jumped to 273.0 to 274.2 cents. That represents an increase of roughly 17.8 to 17.9 cents per litre, explaining the headline description of a 17-cent surge while showing that the exact regulatory increase was closer to 18 cents.
The scale becomes clearer when translated into a fuel purchase. An additional 17.8 cents per litre means another $17.80 for every 100 litres. A commercial vehicle taking on 300 litres would face roughly $53.40 more for the same quantity of fuel. P.E.I. gasoline, meanwhile, did not share the Saturday surge: regulated self-serve regular gasoline remained between 204.6 and 205.7 cents per litre. The divergence illustrates why diesel has become the more serious pressure point in the current energy shock.
Gasoline and Diesel Are No Longer Moving in Lockstep
Gasoline and diesel begin with the same basic raw material, but their retail prices can move very differently because they serve different markets and depend on different refining processes. Ottawa’s gasoline movements reflected a combination of changing wholesale costs and the seasonal switch away from summer-grade fuel. Diesel, by comparison, is being squeezed by shortages of middle-distillate products at a time when freight, agriculture, construction and industrial users still need large volumes regardless of what passenger-car gasoline demand is doing.
That distinction is increasingly visible in Canadian pricing. Kalibrate Canada’s September 11 daily survey put its volume-weighted national regular gasoline price at 185.6 cents per litre. Diesel was already dramatically higher at 262.0 cents, after rising 8.6 cents in a single day in the survey. Ottawa’s surveyed diesel price was 251.0 cents per litre on September 11 even before the next round of market pressure. The pattern matters because a decline in gasoline cannot automatically be treated as evidence that the broader fuel-price problem is easing. Refined products are experiencing very different supply conditions.
The Global Diesel Squeeze Is Bigger Than the Crude-Oil Story
The International Energy Agency’s September assessment provides the clearest explanation for diesel’s unusual strength. Global oil production fell by 1.6 million barrels per day in August to 100.1 million barrels per day, while more than 10 million barrels per day of Gulf production remained shut in amid security disruptions. Refinery throughput was also 4.2 million barrels per day lower than a year earlier. Those constraints helped push Atlantic Basin refining margins to record levels, led specifically by sharply higher diesel margins.
The shortage becomes even more striking when refined products are separated from crude. The IEA said diesel and gasoil account for nearly 30% of worldwide petroleum demand, while U.S. diesel product prices had surpassed the equivalent of US$200 a barrel in early September. Net diesel and gasoil exports from Gulf producers and Russia were about 1.6 million barrels per day below February levels. Those regions had previously accounted for almost 45% of global seaborne diesel trade. In other words, Canadian pumps are being affected not merely by expensive crude but by a shortage of the finished product motorists and truckers actually need.
P.E.I.’s Furnace-Oil Jump Shows the Shock Extends Beyond Vehicles
The P.E.I. adjustment also contained a warning for households preparing for colder weather. IRAC’s September 12 pricing tables raised the maximum after-tax furnace-oil price to 215.9 cents per litre, compared with 199.1 cents the previous day. That is a 16.8-cent increase in the regulated maximum price. On a hypothetical 1,000-litre delivery, the difference amounts to $168, assuming the customer paid the relevant maximum price in both cases. The actual bill will depend on the amount delivered and the seller’s price.
The shared movement between diesel and heating oil is not accidental. Both are middle-distillate products and are exposed to many of the same refining and international supply pressures. For Atlantic Canada, that creates a particularly uncomfortable seasonal problem: a diesel shortage can affect transportation businesses at the same time that higher distillate values raise heating costs. P.E.I.’s regulator normally makes scheduled petroleum adjustments twice each week, but it used an unscheduled interruption for the September 12 diesel and furnace-oil changes. That exceptional step underlines how quickly wholesale conditions had moved.
Federal Fuel-Tax Relief Is Cushioning a Much Larger Market Increase
One important detail can easily be missed when pump prices rise this quickly: Canadians are currently paying these prices while the regular federal fuel excise tax is temporarily suspended. Ottawa recently extended that suspension through January 31, 2027. The measure removes 10 cents per litre from the normal federal excise tax on gasoline and four cents per litre from diesel. The government estimates its fuel-tax measures will provide $5.3 billion in total relief during 2026-27.
That creates a useful counterfactual. Without the temporary federal policy, the statutory excise component embedded in gasoline and diesel would normally be higher, all else being equal. Yet P.E.I. diesel still reached a regulated self-serve minimum of $2.73 per litre. IRAC’s September 12 breakdown explicitly showed the federal excise-tax component at zero for both gasoline and diesel. The episode therefore demonstrates the limits of tax reductions during an international supply crisis. Governments can remove part of the tax burden, but rapidly rising refinery, wholesale and transportation costs can still push final prices substantially higher.
Diesel Costs Can Travel From the Pump to the Price of Goods
Diesel matters far beyond owners of diesel passenger vehicles. Trucks move food, building supplies, packages and industrial goods across the country, while the fuel is also heavily used in agriculture and construction. New Brunswick offers a concrete example of how higher diesel expenses can be translated directly into commercial costs. Its provincial haulage-rate system applies a fuel surcharge when diesel exceeds a $2-per-litre benchmark. For the September 4-to-17 period, a reviewed diesel price of $2.51 per litre triggered a 7.5% increase to applicable base haulage rates.
That mechanism does not mean every Canadian retail product immediately rises when diesel increases. Businesses can absorb some costs, negotiate contracts, improve routing or delay price adjustments. But sustained fuel inflation creates pressure somewhere in the system. At P.E.I.’s new regulated minimum of $2.73 per litre, a 500-litre fuel purchase costs $1,365. A 17.8-cent overnight increase alone represents $89 more on that purchase. Multiplied across repeated fills and fleets of vehicles, seemingly small per-litre movements can quickly become significant operating expenses that freight companies, farmers and contractors must manage.
The Next Moves Will Depend on Global Supply, Not Just Canadian Demand
The immediate outlook remains unusually uncertain because the forces behind the latest increase are international. Brent crude settled at US$104.61 a barrel on September 11 and West Texas Intermediate at US$100.05 after an exceptionally volatile week. Reuters reported that both benchmarks were still heading for weekly gains of more than 8%, while U.S. diesel prices had risen above $6 per gallon. At the same time, the IEA reported shrinking inventories, severe disruptions to Middle Eastern exports and record refinery margins in parts of the Atlantic Basin.
For Canadians, that means the direction of the next pump-price adjustment may depend as much on shipping routes, refinery operations and geopolitical developments as on driving demand at home. Ottawa’s seven-cent gasoline rebound showed that even a normal seasonal price break can disappear rapidly. P.E.I.’s nearly 18-cent diesel increase demonstrated the greater vulnerability of refined fuels when supplies become scarce. Short-term declines remain possible in a volatile market, but until diesel availability and global petroleum flows improve materially, sharp overnight moves are likely to remain part of the fuel-price landscape.
