(19 Jan 2014, 11:47 am)Michael wrote Not sure, they just don't seem to be like to be on the roads, shame cause i like them, they seem to have alot of problems on the west Durham swift when they were on
It's down to how powerful the engine is in terms of power and size. I'll give you an example. Take a look at Arriva's X18. Now the VDL DB250 Lowlanders have quite a high amount of BHP and that alone combined with the 9.0L DB250 engine, is more than sufficient to power a bus upto Alnwick or Berwick on a daily baiss without having to go near maximum RPM on the dual carriageways or rural B roads. Therefore, the engine is working less harder and keeping the vehicle cooler whilst reducing wear and tear on the engine. Now take a look at the ADL Enviro 400. For the E400 to perform the same as the DB250, the E400 will have to go near maximum RPM to achieve what the DB250 can achieve. The E400 in comparison to the DB250 only has a 6.7 Cummins engine and only 240bnp. That means that a turbocharger is needed for the E400 to cope now, if the turbo fails or deteriorates, then the engine is left working on it's own whilst trying to power up the Northumberland Coast, therefore the engine is being strained thus resulting in wear and tear and just recently noted by 7510 going up in flames, the engine also gets too hot and due to the heat of the engine, this causes the waterpipes to heat up meaning that the bus is overheating and either has to be taken out of service or, will go on fire as 7510 did. Dennis vehicles have always had problems winth performance and overheating due to the size of the engines. The 2000 ELC Tridents had to get the sensors taken out when they were new. Take this as an example, when Arriva purchased 7430 - 7435 for the 602, they suffered the same problems as the E400 due to the nature of the route then, when they transferred to Blyth for the 308 due to not coping on the 602, they again couldn't cope but this time, due to wear and tear; and also the distance of the route so a couple of years later, they were transferred to Jesmond for the 306 when 7436 -7442 became available for the 308 and on evenings and Sundays, they had a rest and the Palatine 2 or Volvo B10 operated the 306 to conserve the ALX400's.