Background Information

A New Beginning…

Compared to a typical high performance motorcycle engine our proposed hybrid engine will be half the weight (30 Kg), half the size (350 mm x 300 mm x 160 mm) and twice the power density (300 kW per litre). These figures are consistent with the BMEP (Brake Mean Effective Pressure, used for comparing engine performance) that is being achieved elsewhere but in a vastly reduced form factor. Reducing the weight of the petrol engine to just 30 Kg and utilising the latest lightweighting technologies to bring the generators down to 10 Kg the hybrid power train is expected to be a like for like weight reduction in terms of the batteries removed from an electric only vehicle, i.e. hybridisation is weight neutral.

Why Is This Important?

The same EU research shows “contribution from PTWs increases to 10% & 20% of total road transport NOx & PM emissions respectively by 2020” largely due to introduction of NOx & DPF after treatments for passenger cars and heavy duty vehicles as Euro 5 & Euro 6, i.e. motorcycle %-age goes up due to reduction in emissions from other vehicles.

Hybrid Engine Market Overview

  Meteor Power Mahle Range Extender Mahle Downsized Engine Jaguar Land Rover Ultraboost
Power (kW) 90 30 150 284
Torque (Nm) 74 74 280 515
Capacity (cc) 300 900 1200 2000
BMEP (Power) 22.5 10.0 37.5 26.22
BMEP (Torque) 31 10.33 29.32 32.36
Downsizing Ratio 70% n/a 50% 60%
Power Density 300 kW/litre 33.3 kW/litre 125 kW/litre 142 kW/litre
Engine Type Serial Hybrid Serial Hybrid Downsized Downsized

EU Motorcycle Emissions Legislation

  EURO 2
Apr 2004
Jan 2006
Jan 2016
Jan 2020
CO 5.5 2 1.14 1
THC 1 0.3 0.17 0.1
NOx 0.3 0.15 0.09 0.06
PM 0.045
NHMC 0.068

The Euro 5 motorcycle standards due to become law in 2020 are the same as the current Euro 6 automotive standards, i.e. any engine that can pass the current four wheel regulations will, subject to some minor variations, also pass the future two wheel regulations.

Honda VFR800 Emissions Test

Emissions Type Average
CO (g/km) 1.25
THC (g/km) 0.2
NOx (g/km) 0.14
CO2 (g/km) 158.8

Although only an 800cc motorcycle the Honda VFR800 represents a good example to focus on as it is the only model that has been tested by a number of different organisations with very similar results from each test. In Meteor Power’s experience a 1000cc sports motorcycle is much more likely to deliver higher average CO2 emissions than the VFR800, reaching up to 200 g/km CO2 under an urban cycle.

EU Funded Motorcycle Emissions Research (Motorcycles Over 750cc)

Emissions Type Urban Rural Highway
CO (g/km) 1.607 0.304 0.375
HC (g/km) 0.243 0.054 0.047
NOx (g/km) 0.061 0.022 0.076
CO2 (g/km) 171.2 109.6 118.8

This data is based on the Best Available Technology of the eight 750cc+ motorcycles tested by the AECC (Association for Emissions Control by Catalyst), i.e. in this case represents the best 20% performance of the Euro 3 motorcycle class per pollutant. This data was used as the basis for the EU funded document available from

How Else Will We Make A Difference?

Greatest opportunity in transient control optimisation is reduction, and potential complete removal, of process responsible for generating the majority of NOx and HC emission, i.e. constant changes in throttle input requiring even minor changes in engine speed.

As part of the engine and power management we will incorporate latest Bath University research on “Stochastic dynamic programming in the real-world control of hybrid electric vehicles” []. This will improve forecast state of charge requirements based on operational efficiency in real world driving conditions.

The compact 3-cylinder 4-stroke design offers significant packaging advantages over gas turbine and rotary engines with better thermodynamics. Leading rotary engine supplier, AIE, suggested they would need a much larger form factor to produce 90 kW and couldn’t be sure of meeting any automotive emissions targets. More importantly, demonstrating our ‘transient control optimisation’ along with other emission reductions technologies and power distribution capability in this form will key licensable IP protected technologies to OEMs that can then be incorporated in to their next generation engines rather than becoming a high volume engine manufacturer ourselves.

It is anticipated that the four wheel implementation will utilise a larger battery pack to ensure minimum range requirements for CO2 ECE calculations guidelines, i.e. 40 MPG equates to 7.06 litres per 100 km. Based on the ECE guidelines for declared CO2 emissions for hybrid vehicles being able to travel just 25 km under electric only power would deliver a 50% improvement over declared CO2, i.e. 3.53 litres per 100 km. Being able to travel 50 km would result in a 67% improvement, i.e. 2.35 litres per 100 km whilst being able to travel 100 km under electric power would result in an 80% improvement in declared CO2, i.e. 1.41 litres per 100 km.

For more information on the ECE calculations please see paragraph of the following document: