Since the economic downturn, the estimated average distance of seaborne crude trade has risen by an average of 1.8% per year, with Asia now representing 55% of global import demand (38% in 2003). Shifts in countries’ crude import sourcing patterns and the impact of vessel upsizing have helped to support tonne-mile growth despite the weakness of global oil demand. The Graph of the Month shows examples of routes where change is occurring owing to strong Asian demand and softening Western consumption. 
Mr Big Stuff
The strongest demand growth over the last decade has been for VLCCs. VLCC shipments on their bread-and-butter routes eastbound from the Arabian Gulf (AG) have grown at a CAGR of 4.8% p.a. since 2003, and are projected to reach 12.3m bpd in 2013. However, VLCC fleet growth has been even faster in recent years (8% and 6% in 2011 and 2012 respectively). Fortunately, VLCCs have also benefitted from a distance factor, as demonstrated by the Caribs-East route, shown on the graph. The growth in crude volumes from the Caribbean to China has led to VLCC tonne-mile demand on this route increasing by 39% since 2010. Similarly, tonne-mile growth on the WAF-East route has further boosted VLCC demand, as China and India diversify their imports away from reliance on the AG.
Middle of the Road
Suezmaxes has endured a more difficult time since the recession, and tonne-mile demand on Suezmaxes is estimated to have declined by 0.5% p.a. since 2007. Tonne-miles on WAF to North America, a key Suezmax route, have declined by 27% over 2010-12, as US imports from West Africa fell by 51%. Yet, tonne-miles in this sector are estimated to have risen by 1.6% y-o-y in 2012, and are projected to increase 6.9% y-o-y in 2013. Whilst this is partially a bounce-back from prior weakness, Suezmaxes have also been helped by shifts in crude trade flows. Their share of AG-Med trade has grown as southern European nations have had to replace reduced Russian Black Sea cargos, as the graph shows, whilst the Iranian embargo has reduced VLCC trade on this route.
Small Ship Syndrome
Suezmaxes have also been helped by the greater economies of scale which they offer, and in 2012 they have taken a greater share of tonne-mile trade on the Caribs-US route. Suezmaxes increased their market share on this route to 38% in 2012, up from 23% in 2010. This increase came at the expense of Aframaxes and Panamaxes and was despite the fact that overall volume on this trade route is in decline. Current weak Western markets pose a problem for uncoated Aframax and Panamax crude vessels, particularly given the short-haul nature of many of these routes. However, growing long-haul product trade routes offer some relief for coated vessels in these sectors.
Under the surface of weak freight markets, significant changes have been occurring in the geography of crude trade which, coupled with the trend towards upsizing, have favoured the largest ships. For example, VLCCs are projected to make up 68% of all crude tonne-miles in 2013, up from 62% in 2010. Ultimately, these factors are changing the employment patterns of all ship types in the crude tanker sector.

-- Source from Clarkson Research Services