S1 Low-Floor Electric Paratransit Bus


Optimal S1LF Arriving Q3 2021
The S1LF takes full advantage of Optimal-EV's OEM-quality design and engineering to introduce a product that is both C/FMVSS and ADA compliant. Our low-floor design, which is made possible by the innovative packaging of battery-electric propulsion, allows for ultra-low 11" step-in height and quick deployment of an ADA-compliant accessibility ramp without the need for the added complexity of kneeling suspension.
Key Features
The innovative fully-electric powertrain of S1LF allows for zero-emission operation while providing unparalleled user experience and performance. With 125+ miles of range, lower maintenance and energy costs*, and a highly adaptable design, our S1LF products are sure to meet your EV Paratransit Bus needs and excel in your fleet.
Standard Chassis Equipment
E450 Ford Chassis Platform
LT225/75R16 Tires​​​​​​​
Charge Level 1,2 Standard
Level 1,2 Full Charge in < 8 Hours
Charge Level 3 w/ DC-FC (Opt.)
Level 3 Full Charge in < 2 Hours
Charger Voltage - 240V (Level 2)
Charger Voltage - 480V (Level 3)

Standard Body Equipment
Back-Up Alarm
Heated Remote Mirrors
Front-Mounted Observation Window
Modesty Panel & Hand Rails
Standard Solid Windows
Black-Out Rear Cap
Electrically Actuated Door
Exterior Grade Undercoating
Lightweight Composite Floor
Lightweight Composite Body
Molded Fiberglass Exterior
Gerfloor Flooring
Interior Stepwell Lighting
Popular Optional Equipment
Back-Up Camera
Ceiling-Mounted Handrails
PA Systems
Interior/Exterior Camera Systems
Painted Skirts
Full Body Paint
Rear Exit Door
Roof Hatch
Keyless Entry - Key Fob
Bicycle Racks
Spare Tire
Stainless Wheel Covers
Overhead Luggage
Driver’s Storage Compartment
Energy-Absorbing Bumpers

Exterior Width
Exterior Height
Bumper to Bumper Length
Ground to First Step
Interior Width
Interior Height
Door Opening
Max. Speed
Traction Motor
Operating Temp.
42" x 79.6"
14,500 lbs
70 mph
Proterra 113 kW
280 kW
-27° to +133°F
> 125 miles
A variety of seating and storage options ensure the Optimal-EV S1LF can be configured to your fleet's optimal specification. We will work with you to ensure our products provide the best combination of seating, accessibility, comfort, and performance on the market.
Stay Connected with OEM Dash Cluster
Familiarity of OEM Column Shift Mechanism
Popular Floorplans
*Fuel savings based on 35,000 miles per year, ICE: 10mpg, $3.3/gal, EV: $0.1 kW/hr, 130 EV miles per charge
  Maintenance cost savings based on $0.19/mile (Source: California EPA Air Resources Board, 2016)
**Estimated range dependent upon: ambient temperature, drive cycle, loading condition, ancillary loads, etc.
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