Every underbone sold in Vietnam claims to be frugal, but the manufacturers publish actual test figures, and they are not the same. All numbers below come from Honda VN and Yamaha VN model pages (retrieved 23 September 2026) - manufacturer figures under standard test conditions, with real-world economy varying with load, speed and traffic.
The verified economy ladder
- Honda Future 125 FI - 1.47 L/100 km
- Honda Wave RSX (PGM-FI) - 1.56 L/100 km
- Honda Super Cub C125 - 1.55 L/100 km
- Honda CT125 - 1.61 L/100 km
- Honda Wave Alpha - 1.72 L/100 km
- Honda Blade - 1.85 L/100 km
- Yamaha Sirius RC - 2.08 L/100 km
- Yamaha Exciter 155 VVA - 2.07 L/100 km
- Honda Winner R - 2.59 L/100 km (UDC test method)
- Honda CBR150R - 2.91 L/100 km
The pattern behind the numbers
Injection and low weight win: the Future’s 125-class engine with fuel injection tops the table while the sportier the machine gets, the more it drinks. The two manual-clutch sport bikes are the thirstiest - fairings and revs cost fuel.
Range matters as much as economy
The CBR150R is the least efficient here, yet its 12-litre tank gives it the longest seated range of the group. The Wave RSX balances both: 1.56 L/100 km from 4.0 litres. If you commute, economy is king; if you tour, multiply economy by tank size before judging.
Rental context
The price-published rental classes at our counter are the Wave and Sirius - the second-thriftiest engine in the table and the mid-pack Sirius. Contact us to confirm current availability. And remember: rider behaviour moves real economy more than model choice does - our fuel-economy improvement guide covers the riding habits that matter.