Factors that affect Fuel Efficiency, especially on motorcycles, are often overlooked merely because they are either considered unimportant or the user is not aware of the significance in terms of their contribution to the overall fuel economy. Most of these have been mentioned in the main text but attention should be drawn to a few of the less considered.
   
Binding brakes
It does not take an Einstein to understand that increased friction and anything that hampers free rotation of the wheels can, in the final analysis, end up increasing fuel consumption. Obviously the cure for a situation like this is to get the system serviced, but consider the rider who unsuspectingly leaves his foot on the brake pedal even slightly will also end up wasting fuel. In fact, in simulated tests, a 2lb weight on the brake pedal increased fuel consumption by just over 20 percent, surely a heavy price to pay for a bad habit, a problem easily corrected by a slight readjusting of the right foot on most two-wheelers today.
  
Aerodynamics
Cars travelling at high speeds are greatly affected by aerodynamics because of their large frontal areas. Two-wheelers in contrast offer a much-reduced frontal area and in India are not capable of the speeds where aerodynamics really starts to take effect on the Fuel Efficiency. As a rule and in the absence of conclusive data in this regard, any help that a vehicle gets by way of becoming better streamlined should be worth a bit and the bikes with well designed fairings could be better off.
  
Transmission and the gear ratios
This factor is linked very closely to the entire Performance of the bike. It is usually believed that a bike with higher gear ratios would produce better economy and this is only true to the extent that the rider uses the ratios in a way that benefits Fuel Efficiency. Sticking a bike in the highest gear and leaving it there could hurt economy unless it is on an open road with smooth gradients and the bike is not being buffeted by strong head winds. Trying to take advantage of the high gearing on a bike when the conditions are not conducive, like tackling a hill in top gear, would mean large throttle openings to maintain speed and a consequent loss in economy. It would be more sensible to anticipate the gradient and work up to the right speed in a more controlled and progressive manner so that sudden and excessive throttle and a lower gear do not have to be employed to crest the gradient. Improper riding techniques in such circumstances could result in a loss of even 20 to 30 percent in Fuel Efficiency, with the risk of detonation and accelerated engine bearing wear.
 
Tuning
Wrongly adjusted ignition timing could account for about 10 percent wasted fuel. Under full engine load, old misfiring spark plugs can cost anything from 20 to 40 percent in lost economy.
A dusty and clogged air filter may increase fuel consumption by seven percent and a leaky float needle and seat may push fuel consumption up by a staggering 50 percent.
  
So, with motorcycle manufacturers doing their best to provide the user with products aimed at delivering the best that they can, the moral of the story remains that the biggest contribution to fuel economy comes from smooth riding and regular maintenance.