For 2008 the RS 125 was brought into line with Euro 3 emissions limits.
| MODEL | APRILIA RS 125 2008 |
| Year | 2008 |
| Engine Type | Rotax 122 single cylinder, two-stroke, reed valve intake, aluminium cylinder with Nikasil-coated liner |
| Displacement / Capacity | 124.8 cc / 7.62 cu in |
| Bore X Stroke | 54.0 x 54.5 mm / 2.1 x 2.1 in |
| Compression Ratio | 12.5:1 |
| Cooling System | Liquid cooled |
| Max Power | 17.6 kW / 24.1 hp @ 10000 rpm |
| Max Torque | 17.0 Nm / 1.7 kgf-m / 12.5 lb-ft @ 9750 rpm |
| Ignition | Electronic, ECU AC34 cm082401 |
| Induction | Dell'Orto VHST 28 CD carburettor, membrane and power valve |
| Start System | Electric |
| TRANSMISSION SPECS | |
| Lubrication | Separate mixing with variable displacement volumetric pump |
| Gear Box | 6 Speed |
| Clutch | Wet, multi-plate (oil bath) |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | Sloping twin-spar frame in thin-wall box-section cast aluminium with reinforcement cross-ribbing |
| Front Suspension | 40 mm upside-down hydraulic telescopic fork, 120 mm / 4.7 in travel |
| Rear Suspension | Cast aluminium swingarm, single hydraulic monoshock with adjustable spring preload, 120 mm / 4.7 in travel |
| Front Brakes | Single 320 mm / 12.6 in disc, radial 4-piston caliper |
| Rear Brakes | Single 220 mm / 8.7 in disc, 2-piston caliper |
| DIMENSION SPECS | |
| Overall Length | 1955 mm / 77.0 in |
| Overall Width | 720 mm / 28.3 in |
| Overall Height | 1100 mm / 43.3 in |
| Seat Height | 805 mm / 31.7 in |
| Wheelbase | 1345 mm / 53.0 in |
| Ground Clearance | 163 mm / 6.4 in |
| Dry Weight | 127 kg |
| Wet Weight | 137 kg / 302 lbs |
| WHEEL SPECS | |
| Front Tyre | 110/70-R17 |
| Rear Tyre | 150/60-R17 |
| FUEL SYSTEM | |
| Fuel Capacity | 14 Litres / 3.7 US gal |
| Fuel Consumption | — |
| Top Speed | 135 km/h / 83.9 mph |
For 2008 the RS 125 was brought into line with Euro 3 emissions limits. A Dell'Orto VHST 28 carburettor, a new electronic control unit and twin catalytic converters replaced the old set-up, and shorter final gearing was fitted, at the cost of some peak power and top speed. Styling and chassis stayed as on the 2006-07 bike, with colours including black, fluorescent red and Talmacsi and Spain's n.1 replica schemes.
