Allison is to supply 220 T2100 xFE transmissions to First Bus in the UK.
The order is for the retrofitting of all ADL Enviro 200, Optare Solo and Optare Versa buses in the First Bus fleet currently equipped with Allison’s T2100 transmission.
It follows trials, which showed improved fuel consumption by 8.5% when upgraded with xFE Technology. Savings made on diesel bills are expected to pay back the investment in the new transmissions in less than 13 months.
First Bus conducted its xFE study across the UK throughout 2020 on nine ADL Enviro 200 buses and one Optare Solo. Most of these vehicles were 12 years old and were fitted with xFE at the point of their final routine transmission replacement.
Fuel consumption was compared with buses of the same type and took into account factors such as duty cycles, traffic conditions, route topographies and vehicle life stage.
“As part of our focus on becoming a leader in the transition to a low-carbon future for public transportation, First Bus has committed to ceasing the purchase of any new diesel buses after 2022,” said FirstGroup technical manager, Peter Mambara.
“However, we recognised xFE as a stepping-stone technology on the path to full electrification. We had seen stories of other fleets achieving 7%-8% fuel savings from xFE in urban driving conditions, but wanted to independently assess the savings on buses that also serve on rural routes. The 8.5% improvement was convincing evidence the upgrade will help reduce our fleet’s CO2 emissions and makes good financial sense.”
For his part, Allison OEM account manager and area sales manager, UK and Ireland, Jade Noble, added: “As the xFE transmission has demonstrated with First Bus, in addition to other trials Allison has undertaken globally, there is a lot that can be done to make the current generation of diesel engines cleaner.
“Even towards the end of a vehicle’s life, there is both an immediate environmental and short term business case to be made for upgrading to the latest fuel saving transmission technology.”
First Bus will install the xFE upgrades during the next 18 months when last-life transmission replacements are due on 142 Enviro 200s, 60 Optare Solos and 18 Optare Versas. Though such buses typically remain in service for 15 years, with transmissions routinely replaced every two to three years, these vehicles could now remain in service for 24 months longer than previously anticipated, as xFE has a longer lifespan than comparable heavy-duty transmissions.
Allison maintains its latest fully automatic transmission for buses delivers extra fuel efficiency by optimising gear ratios, which enable torque converter lock-up in first gear and operation at lower engine speeds in higher ranges.
The strategy is suited to city and transit buses.