SHIPOWNERS began installing exhaust gas scrubbers more than six years ago to comply with the IMO2020 regulation — and they’re still adding more, according to data from Clarksons Research.

Ships with scrubbers can burn cheaper high-sulphur fuel oil; ships without them mostly use very low sulphur fuel oil. The higher the premium of VLSFO to HSFO, the greater the savings for scrubber-equipped tonnage.

The lesson learnt in the years since IMO2020: shipping disruptions have big effects on the VLSFO-HSFO spread.

Disruption effect on scrubber spread

Not all disruptions are positive — the pandemic caused the spread to collapse — but scrubber economics have improved during the Hormuz crisis, as they did to an even greater extent after Russia’s invasion of Ukraine. 

According to data from Ship & Bunker, the average VLSFO-HSFO spread at the world’s top 20 refuelling hubs hit $314.50 per tonne on January 7, 2020, just after IMO2020 came into force.

Shortly thereafter, the pandemic struck, and the spread collapsed at around $50 per tonne for most of 2020, hitting a low of $45 per tonne on November 2, 2020.

The spread surged after Russia’s invasion of Ukraine, hitting an all-time high of $420.40 per tonne on July 5, 2022.

It normalised the following years; in 2023-2024 the spread averaged $118 per tonne. It sank below $100 per tonne in 2025, averaging just $74 per tonne last year at the top 20 hubs, according to Ship & Bunker data.

Then the Hormuz crisis came to the rescue.

The spread averaged just $70 per tonne in January-February, then more than doubled after the war broke out, hitting a Hormuz crisis high of $179 per tonne on March 20.

The prices of VLSFO and HSFO have since plunged as a result of the US-Iran peace framework, yet the spread has remained wide. As of Friday, it was still at $160.50 per tonne.

Bunker fuel prices more than doubled at the peak of the Hormuz crisis.

On March 19, the average price of HSFO at the top 20 ports hit an all-time high $916 per tonne, compared to the January-February average of $426 per tonne.

Average VLSFO pricing peaked at $1,053 per tonne on March 20, compared to the January-February average of $496 per tonne.

On Friday, VLSFO averaged $723.50 per tonne at the top 20 hubs, down 31% versus the peak but still up 46% versus January and February.

HSFO averaged $574 per tonne on Friday, down 37% from the peak and up 35% versus January and February.

The faster normalisation of HSFO compared to VLSFO has kept the scrubber spread wide.

Ongoing rise in scrubber installations

It is more cost-efficient to install scrubbers during newbuilding construction than with retrofits. Newbuilding orders have surged, and with that, scrubber installations have increased.

To gauge the trend, Lloyd’s List compared Clarksons Research data on existing installations and newbuilding installations as of this month versus June 2025.

In the tanker segment, 66% of very large crude carriers on the water have scrubbers (including units with retrofits scheduled).

In contrast, 92% of VLCCs on order will be fitted with scrubbers, and that is up from 81% of newbuilding orders a year ago. These numbers confirm growing VLCC owner interest in scrubbers.

Just 40% of existing suezmaxes have scrubbers, but this is poised to rise, with 66% of newbuilding set for installations.

The trend is the reverse for coated aframaxes/LR2s: 48% of on-the-water ships have scrubbers but just 40% of those on order will be fitted, down sharply from 60% a year ago.

The capesize and panamax segments in dry bulk show the same rising scrubber bias as VLCCs and suezmaxes.

For capesizes, 74% of newbuilding orders include scrubber installations, far above the 58% share for newbuilding orders in June 2025, as well as the current ratio of 57% for on-the-water capesizes.

Only 19% of the existing panamax fleet has scrubbers, but 46% of panamaxes on order will have them fitted, compared to 38% a year ago.

The containership segment already has a high scrubber penetration, but the ratio has been falling and is poised to decline further as more non-scrubber newbuildings hit the water.

According to Clarksons data, 80% of boxships 17,000 teu or larger have scrubbers, the largest share of any shipping segment. But that is down from 84% in June 2025, with just 3% of newbuildings set for installation compared to 1% a year ago.

In the 12,000-16,999 teu segment, 64% have scrubbers, down from 66% a year ago, with only 37% of newbuildings set for installation.

One size category showing a modest increase is 3,000-7,999 teu boxships: 30% have scrubbers, up from 27% in June 2025, and 37% of newbuildings are due for installations, which should keep the percentage rising.

However, interest seems to have ebbed over the past year. In June 2025, 46% of 3,000-7,999 teu boxships on order were scheduled for scrubber installations.