And as promised12 Apr 2016 20:22
Had a reply from IR regards the Ocado fleet as follows:-
"We operate a fleet of around 1,300 vans - these are all 3.5 tonnes (gross) weight Mercedes sprinter vans which run on diesel and have been optimised for fuel consumption.
Even at the peak of fuel prices a few years ago, fuel costs made up less than 2% of our sales. Also note that there is a tax shield on fuel costs which works both ways, in a rising and falling fuel cost environment. Also note that changes in oil prices are no 100% passed through to fuel costs.
We have in the past and continue to try keep our fuel costs low by increasing fuel efficiency of the vans, improving routing systems, reducing travel distances and increasing deliveries per van route.
Our leading edge, in-house routing system enables us to minimise road mileage and take full advantage of the payload available by making over 3 million routing calculations per second, finding the most efficient delivery routes. Working with our body constructor Paneltex for many years, we have increased the payload of our 3.5 tonnes sprinter van fleet by 41%.
We also offer our customers the option to choose a 'green' van slot – if we are delivering in an area at a particular time, we can advise at the time of booking, enabling customers to choose an adjacent time slot – thereby minimising drive time and fuel use for deliveries"
So that's straight from the horses mouth as it were