The US and Israel launched strikes on Iran on February 28, 2026, triggering the worst diesel price shock Canadian truckers have seen in years. Iran's closure of the Strait of Hormuz, which carries about 20 percent of global oil supply, prompted the International Energy Agency to call it the largest supply disruption in the history of the global oil market.
The damage at the pump was immediate. Ontario diesel jumped from $1.40 a litre to as high as $2.30 a litre by early April. Fleet transaction data from one Ontario carrier shows the weekly cost of 10,000 litres peaked at over $22,000 in late March, up more than $6,000 from January levels.
A ceasefire was reached April 8. WTI crude plunged roughly 15 percent on the news. But the relief was short-lived. In the first 24 hours of the ceasefire, only one oil products tanker transited the strait. Both sides accused each other of violations within days and prices climbed back above $100.
Since then the market has gradually settled. WTI fell more than 16 percent through May, its worst month since the Covid-19 pandemic, closing near $87 a barrel and roughly 20 percent off its 2026 peak. Ontario pump prices by mid-June had pulled back to around $1.74 a litre, still 24 percent above where carriers were fuelling in January.
The path back to normal pricing depends on a durable peace agreement holding, the Strait reopening to meaningful tanker traffic, and crude continuing to slide. Analysts have flagged significant damage to Gulf infrastructure and refineries from the war, meaning any reopening of the Strait will likely be gradual rather than a clean switch. Futures markets are currently pricing WTI at around US$75 a barrel by end of 2026, which would bring further relief if it holds.
The federal government removed the $0.04 per litre Federal Excise Tax on diesel on April 20, saving carriers $400 per 10,000 litres. It helped, but only partially offset a war premium that at its worst added over $0.80 a litre to the cost of diesel in Ontario.
The direction is right and the trucking community is watching closely. If a lasting agreement comes together and the Strait opens without further disruption, carriers could finally see the kind of relief at the pump that the last four months have denied them. Here's hoping that deal holds and the surprises stop.