(30 Oct 2017, 11:05 pm)mb134 wrote Omnis should be replaced with B8RLEs. They're heavyweight single deck vehicles, to replace them with Enviro 200s or StreetLites would be foolish, though given Arriva, I fully expect it.
On a similar note, even the Wright website labels the StreetLite as a "midi-bus", yet operators are buying them in their droves as replacements for heavy weight single decks...
In my view, it's unlikely that Arriva will replace the Scania OmniCitys with a bus on the Volvo B8RLE chassis.
Unfortunately for many operators, a bus being low carbon emission certified is what makes the business case stack up to order these new vehicles. Regardless of who the operator buys from, buses which are Euro 6 are very expensive. A bus being low carbon certified makes it eligible for the additional fuel subsidy (BSOG) of 6p per km in England and 14p per km in Scotland. This helps build a solid business case for most operators when buying new vehicles, as there is a solid benefit for buying this type of bus as a replacement for the existing vehicle type.
Any buses in Wrightbus' range which have the 'Micro-Hybrid' package achieve Low Carbon Emission Bus Certification (the Wright Eclipse 3 bodied Volvo B8RLEs don't have this package, like the buses on the Volvo B5TL chassis).
JoshP's suggestion for further gas-powered EcoCitys and full size diesel Enviro200MMCs is the most plausible in my view, though a further order for Streetlites in Darlington could suggest that they're still interested in the Wrightbus LCEB range.
With reference to the Streetlite being labelled as a midibus: the Streetlite is! It's the full-size Streetlite Max (11.5m) which is classed as a full-size single deck bus, and it's this type that we see the most of in this region. The main examples of the 'midibus' range of Streetlites in this region are Go North East's "Saltwell Park" branded examples (this is why they're numbered in the 8xxx series as opposed to 5xxx series).