Overheard the bus driver on the way home today...he said during a recent meeting they were told the 300s wouldn't be retired. Rather they are going to be retrofitted as diesels.
I am not sure this sounds feasible. I am not that knowledgeable about engines, but wouldn't think this would just involve removing the natural gas tanks and replacing them with diesel tanks... I assume this would involve replacing the engines. And, if so, I suppose a new transmission would be needed. And even if this was plausible, everything else on the busses is also 12 years old and wearing out.
I would just replace them, but making them Diesel buses sounds interesting. The engines the 300's use is the Cummins L10G. It is the predecessor to the L Plus CNG engine. The L10G is similar to the L10 Diesel engine but I think the L10G cannot run on Diesel. It will be more complicated than just replacing CNG tanks with Diesel tanks, which is why I would just replace the whole bus. The city has 40 Neoplan AN440's (300 Series) which, like you said, are over 12 years old and are wearing out. The city has just ordered 20 New Flyer DE40LFR's and there is supposedly more on the way next year. This might mean they are replacing the 300 Series buses. I guess we will have to wait and see what happens.
To extend the life of the 300s, I would probably do the following:
- Install new wheelchair lifts. Out of the entire fleet, the lifts on the 300s are the least reliable, vs. the slide-out ramps on the 400s and the flip-out ramps on the 700s and Rapid Ride buses.
- Install new Thermo King HVAC units. The HVAC on the 300 series has a setup where it must be manually changed from heat to cool and vice-versa in late April and October, respectively. On the 400s, 700s, and Rapid Ride buses, heat or cool can be used any time of year.
- Replace the Cummins L10G engines with Cummins ISL engines. If CNG is desired, use the Cummins ISL G engine.
- Replace the current floor paneling with the material used by the 700s and Rapid Ride buses.