Spec sheets speak in abbreviations. Most are simple once decoded - and each one marks a real engineering choice. Here are the codes that appear on Honda Vietnam and Yamaha Vietnam pages (retrieved 23 September 2026), with what they mean for the rider.

Engine family codes: KC46E

Honda identifies the Winner R’s engine as the KC46E - a family code for that 149.2 cc liquid-cooled single. Family codes matter to buyers mainly for parts: a code defines which parts bin the engine shares. The code says nothing about performance by itself; the power and torque lines next to it do.

Valve layout: SOHC and DOHC

SOHC (single overhead camshaft) drives the valves with one cam; DOHC (double overhead camshaft) uses two. In this range: the Sirius, Exciter 155 and Hondas generally are SOHC; the CBR150R is the one DOHC, befitting its sport-bike role - higher revving, more valve control. Our SOHC vs DOHC explainer covers the trade-offs.

Fuel delivery: PGM-FI and EFI

Both mean electronic fuel injection - PGM-FI is Honda’s brand name (Wave RSX), EFI is Yamaha’s generic term (Exciter 155). Injection meters fuel electronically for cleaner, more efficient running; our PGM-FI guide has the details. Important honesty rule: Honda publishes no fuel system for the Wave Alpha, and Yamaha none for the Sirius - so no claim is made for either.

Valve timing: VVA

Yamaha’s Variable Valve Actuation on the Exciter 155 changes valve behaviour across the rev range - covered in depth in our VVA explainer.

Efficiency brands: eSP and Blue Core

Honda’s eSP (Enhanced Smart Power) and Yamaha’s Blue Core are scooter-engine efficiency programmes - our eSP vs Blue Core guide compares them. They appear on the scooter pages, not the underbones.

Emissions: Euro 3 and beyond

Honda lists the Blade as Euro 3 - an emissions standard level that defines what the engine may emit. Higher numbers mean cleaner; they also influence which models stay in the line-up over time.

Cooling: air versus liquid

Air-cooled engines (all the semi-automatics here) use fins and airflow; liquid-cooled engines (Winner R, CBR150R, Exciter 155) use a radiator to hold precise temperature under sustained high output - see our cooling explainer.

Renting the alphabet

Our price-published daily classes are the Honda Wave and Yamaha Sirius at 150,000 VND - contact us to confirm current availability. Insurance is not included in rentals - customers arrange their own.