Take the 2-minute tour ×
Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. It's 100% free, no registration required.

I have a two wheeler i.e. bike (Honda company, four stroke) which has four gear. While driving my bike, when I come to downhill slopes, I shift the motorcycle to neutral to save the fuel. (The slopes are not very long, so I cant turn off engine because I have no starter to quickly start it :) ).

But one of my friends suggested not to use neutral, but only hold the clutch while the bike is in gear. So I want to ask, what saves the fuel more between these two cases, shifting to neutral, or just holding the clutch? Or are both of these useless?

share|improve this question

5 Answers 5

up vote 9 down vote accepted

Holding the clutch in is generally not a good idea. The clutch is designed to be used for very short periods between gears, and for holding in first when you are about to pull away. So if you are wanting to coast you should definitely do it in neutral. The difference between these two from a fuel consumption perspective should be marginal.

From a safety perspective, however, I would suggest this would be a mistake:

You are very vulnerable on a motorbike, so using all safety mechanisms at your disposal should be encouraged. Your engine is a safety mechanism when going downhill - you can accelerate out of danger, or you can use engine braking in addition to your brakes in order to slow down safely.

My advice - only use neutral when stationary, and only use the clutch to change gears or to prepare to pull away.

share|improve this answer
    
thanks for your answer –  Shirish Herwade Oct 30 '12 at 10:53
1  
Here in Ohio, it's illegal to allow a car to coast in neutral. Presumably due to the control concerns. –  Brian Knoblauch Oct 30 '12 at 13:13
3  
+1 for "not worth it." It should also be noted that modern fuel injected vehicles (some motorcycles included) shut off the fuel delivery when in "overrun" (i.e. when heading downhill in gear with the throttle closed), so there is no savings to be had by shifting to neutral or pulling in the clutch--in fact, more fuel would be consumed if you did shift in to neutral or pull in the clutch. –  mac Oct 30 '12 at 20:46
    
+1 for mentioning engine braking –  dave00 Oct 31 '12 at 14:36

You need to understand that both consume the minimum amount of gas, but also, if you going downhill in 6th gear, and you have a injection fuel engine, this has exactly the same effect, and the injectors cut all the gas to the cylinders.

Only carburator engines spend gas if you're shifting gear and not accelarate.

For a safety point, never use neutral, even if some bikes have a neutral between 5th and 6th gear, it's easy to shift the top gear and just cruise without gassing up if you can.

share|improve this answer

Coasting in neutral or with the clutch disengaged will save the same amount of fuel. In both cases the engine will return to the minimum idle speed. However you will coast for a slightly longer distance at a slightly greater speed by having the transmission in neutral. This is due to the frictional drag of the wheel turning the chain and the chain turning the internal gears of the transmission. You are also increasing the wear on the clutch release assembly by holding it in the disengaged position. If you normally just coast down the hill with the throttle closed (not accelerating with engine power) the amount of fuel you save will be minimal as the throttle will be off anyway.

share|improve this answer
    
-1 your "slightly longer in neutral" statement is based on incorrect information. In neutral the chain (or driveshaft) is still turning (it's connected directly to the wheel), and the transmission is still turning (the clutch decouples the transmission from the engine, not the transmission from the wheel) –  mac Oct 30 '12 at 20:54
    
thanks for your answer –  Shirish Herwade Oct 31 '12 at 5:26

I don't think this is a good idea. safety is more important than millage. If you holding clutch or neutral gear while downhill, then you may have to put more pressure on brakes . if it is a long hilly drive there's a chance for overheating brake-pads. If it become over heated then brakes will not be work properly. That's why drivers use engine brake in downhill, So I'm not recommending for holding clutch or neutral while downhill.

share|improve this answer

Even if safety were of no concern, you still should not put a motorcycle in neutral at speed. "So if you are wanting to coast you should definitely do it in neutral." Yikes! If your motorcycle has a synchronized gearbox, at the very least you are causing harmful wear and tear on your gearbox by taking it in and out of neutral at high speeds. Worst case scenario, doing so will break it.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.