May 4, 2008 at 9:44 pm #1329RydRyParticipant
Hi all- so today as I was riding I wondered if there was a tried and true range for good fuelmpg and also ease on the bikes engine for shifting- in a car I tend to hit about 3,00 and shift (unless a hurry) sme on bikes felt right today but opening it up/…..May 4, 2008 at 9:49 pm #5981ShannonGParticipant
I would think lower revs=better economy.May 5, 2008 at 1:10 pm #5994swedeParticipant
Yes, always use as high gear as possible and change gear early. Also, you don’t have to go trough every gear while gearing up, some bikes have 5 gears, and you could easily go 1-2-3-5 or even 1-2-4 if you only have 4 gear’s.
Next time you’re out riding, try using higher gear’s, you’ll hear and feel if you’re going too slow on a too high gear.
And as ShannonG says, change gear as soon as you can, around 2k should be just fine, but it all depends on which type of engine you’ve got.
If you want to learn more, you could google for “eco-driving”
JonathanMay 5, 2008 at 7:05 pm #6001BenParticipant
Yes lower revs do translate to better fuel economy, but it’s not always great for the engine. I used to ride my zx6r like that, I would shift at around 6,000-7,000 rpms (with a redline of 15,000) in hopes of getting better gas mileage. I then had a mechanic do a valve adjustment on my bike and when he is looking at the valves he says “Do you use 87 octane?” to which I replied “Nope, I use premium.” He then asks me if I ever open up the throttle and I tell him no and that I shift at 6-7k.
He then proceeds to tell me (and show me) that by not opening the bike up I will collect (and have collected) deposits on my valves. When you shift too early the fuel doesn’t burn long enough or hot enough to get rid of all that gunk in there, so I was actually doing harm to my engine by not cycling it through the revs.
Ever since then and based on my mechanics advice I try and open it up to at least 10k a few times during a ride, this usually happens on the entrance to the freeway. Sometimes I even take it to redline just to make sure I get that ‘extra’ burn plus it makes riding a lot more fun.
With a motorcycle you are already going to be getting a lot better fuel economy than with a car, heck even when I ride my bike hard I still get 42+mpg last time I checked. I’m not saying to redline it all the time, but it is good for the engine if you cycle it through the revs every now and then.
~Best Beginner Motorcycles AdminMay 5, 2008 at 7:08 pm #6002mrathbunParticipant
ICEs are not terribly efficient in most of their rev ranges, especially toward the lower end of the range where they are not near peak torque or peak horse power.
If you are cruising on a level grade you will achieve peak fuel economy by selecting the highest gear that can still maintain your current speed, it requires very little horsepower to maintain a constant velocity on a level grade so you are able to run your engine in its lowest rev range resulting in the best fuel to power ratio.
That is no longer true once you begin to require more horsepower/torque, either because you are accelerating or climbing a hill. If you shift too early, and thus drop your available horsepower/torque, you will burn more fuel getting the engine to climb back through its inefficient range than you would have if you had held the lower gear and shifted later. If you have any experience driving a car with a manual transmission you have probably noticed this effect. Recall times when you may have accidentally shifted to a higher gear than you intended, grabbing 5th instead of 3rd, or stayed in a higher gear while rounding a curve. It required a lot more throttle to achieve the same rate of acceleration in 5th gear – likely floored – than it would have if you had shifted to 3rd.
In general, it is more efficient to keep an engine in its power band while accelerating, and to allow the revs to drop as far as possible while cruising at a constant speed.
You can find additional research by Googling Power Bands, Internal Combustion Engine Efficiency, and by comparing the efficiencies of electric motors to the internal combustion egine.
- You must be logged in to reply to this topic.