Four years later, this dream became a reality when SMRT Buses chose the OC500LE as its first fleet purchase under the re-branded company. Its demonstrator unit had the honour of being number 1 in the new registration prefix and was paraded as the 'First Euro V bus in South-East Asia' with the 'SMRT is Green - Go Green with SMRT' campaign. 66 more units were initially purchased, known to bus enthusiasts as Batch One.
The OC500LE was the first wheelchair-accessible bus (WAB) introduced by SMRT Buses. Launched in 2008, It featured the improved OM457hLA turbocharged engine (11,967cc) with the ZF 6HP 592C Ecomat six-gear automatic transmission. Selective Catalytic Reduction (SCR) technology was used for exhaust treatment, which requires the use of AdBlue to meet the stringent emission standards. The Lawo BENEFIT EDS (orange colour) is LED-based and now standard within the industry, replacing previous flip-dot models. A new interior scheme that would become the standard of new SMRT buses and future refurbishments was adopted, and each OC500LE was installed with Konvekta air-conditioning unit.
Subsequently, SMRT Buses was satisfied with OC500LE's performance, and made a further purchase of 67 units. These Batch Two buses were introduced in July 2009, with a few slight changes made to its interior, bringing the total fleet to 134 buses. All units were assembled by the Thailand-based Thonburi Busbody, with the bodywork supplied by Gemilang Coachworks.
Unfortunately in December 2009 TP1854 was destroyed by fire in Perth, Australia while on revenue service. Nobody was injured in the incident. In January 2010, SBS Transit declined the purchase of OC500LEs and returned its own demonstrator unit that it had evaluated for months to the dealer Cycle and Carriage. This unit subsequently went to private operator Chitson Transport.