Throttle Question?

[CLP]

Normally I roll on and off the throttle to keep the bike at the same speed, but when I’m on the four-lane sometimes I lock the throttle and just ride. I can lose about 5mph going up some of the steeper hills and gain about that coming down them. My question is which would get the better gas mileage? I don’t exactly understand how the throttle system works. If the throttle is locked in you would think that it would be putting the same amount of fuel in constantly, but if the engine rpms go up when you’re going down the hills wouldn’t that mean the jets were squirting fuel in more often? I check my gas mileage at every fill up. I usually get about 47.5 mpg, but I like to play with it and see how much I can squeeze out of it. It drives my cager buddies crazy when I casually mention my top mpg which to date is 51.2mpg.

[Deeppurple52]

clp..... NO. With TP constant the rpm will vary as load increases or decreases. The same happens in your car. Start up hill, you add power, downhill decrease power. A throttle lock is not a cruise control since it cannot vary TP to maintain speed.

[CLP]

Originally Posted by Deeppurple52

clp..... NO. With TP constant the rpm will vary as load increases or decreases. The same happens in your car. Start up hill, you add power, downhill decrease power. A throttle lock is not a cruise control since it cannot vary TP to maintain speed.

I'm not looking for cruse control. I understand how a throttle lock works. My question is which way do you think will give you a little better gas mileage and why?

[07Ninja250]

I've always heard that a steady throttle will yield you the best mpg. It doesn't get more steady than being locked in place.

Of course you'll use more fuel if you squeeze the throttle to maintain speed going uphill, and I doubt you make it all back up when you let off going down the other side. Personally I rather burn an extra shot glass of fuel to keep my speed steady going uphill.

[Jake '53]

Originally Posted by CLP

I'm not looking for cruse control. I understand how a throttle lock works. My question is which way do you think will give you a little better gas mileage and why?

With carburator, the fixed throttle, allowing speed to vary with load was the most efficient way to run as long as the engine rpm stayed in it's best efficiency range. Working the throttle to maintain a constant speed would spray a little extra fuel into the system whenever you twist your wrist. If you're trying to maintain constant speed going up and down hills that happens when you start up a hill and when you get on the throttle again at the bottom of a hill. On older cars with carburators and large accelerator pumps it was significant. EFI does the same thing but more efficiently. As long as you roll on/off smoothly you probably won't notice a difference between constant throttle and constant speed.

[Deeppurple52]

The simplistic answer is steady. The realistic answer is to vary throttle position to maintain speed. You will save more gas rolling off a little power on the downhill than you will use adding power on the uphill. We see that frequently here in the mountains. Uphill under load uses more fuel. Downhill with no load saves a lot of fuel. Example? On the 1600 the 110 mile uphill ride from Phoenix (1100') to Clint's Well (7400') yeilds about 41-42 mpg. The downhill return trip yeilds 48-50 mpg. The 900 gets 50 up and 60 back. Those of us that live near the mountains understand the benefit of downhill.
The MPG screen on the Toyota shows this very clearly. Start uphill with the cruise on and it will add throttle to maintain speed. Mileage will drop from a level ground 23 mpg to around 8 mpg. Start downhill and the cruise will reduce throttle and mpg will go to 60-80 mpg. Interesting to watch.

[CLP]

Thanks to all you have answered my question. Easy on and off it is.

[CLP]

Originally Posted by CLP

Thanks to all you have answered my question. Easy on and off it is.

Hey that was a milestone for me. My 100th post. No wait now it's 101. Oh well easy come easy go.