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Riding for fuel economy

HappyHighwayman

HappyHighwayman

It's all in the reflexes
Joined
Apr 8, 2009
Location
San Francisco
Moto(s)
Rad Rover
Name
Jordan
Today we rode from the city to Napa via Berryessa lake and towards the end there were no more gas stations on the way until Napa. My reserve kicked in and I went 40 miles before we hit Napa and when I refueled I had about 0.3 gallons left. On that tank I got about 43 MPG.

Towards the end when I wasn't sure how far I could go, I kept the gears relatively high...as a result I was out of the power band but I kept my RPMs low.... was this an appropriate response to running out of gas but knowing we were close to a station?

When we did the winding and twisting hills I was typically in 2nd the entire time just revving up and down as needed...they were a lot more fun at 8000 rpm in 2nd that 6500 rpm in 3rd.

Additional question what kind of fuel savings can I expect riding at a cruising RPM vs. power band RPM?
 
You should've topped off in Napa before heading towards Berryessa Crusing RPM should give you about 10% better MPG. like aroung 48 MPG. At least that's what I got on my old F2: 43-48 MPG.
 
Yeah I should have , I had an opportunity. Totally my fault.

But we came from south towards Napa, not away from napa.
 
Late in the ride last Sunday the bike was sucking fumes. I didn't want to have to gas up before I made it back to the barn. I lowered the windscreen, laid on the tank and drafted a semi. My normal is about 48mpg for that ride. The computer was registering up to 67 mpg in full conservation mode.
 
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I'm not going to bother pulling examples from fuel maps, but the lower the RPM, the less fuel you use, in all cases. 100% throttle at x revs uses less fuel than 50% at 2x revs. Short-shifting is exactly the appropriate response for a feed forward-only fuelling system like carburation.
 
Another really interesting thing: At some points there were speed warning signs set up that display how fast you're going and they consistently registered ~5 MPH slower than my speed was set for. I was aware that most motorcycles over-register but it was nice to see how much.

I know they make devices that you can wire up that give you a more accurate speed and I'd love to install one....this basically means that when I've been cruising at 80 I'm doing a paltry 75.
 
thenewwazoo said:
I'm not going to bother pulling examples from fuel maps, but the lower the RPM, the less fuel you use, in all cases.
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So, holding the throttle at 6000RPM in neutral uses more fuel than climbing a mountain with a headwind at 5000RPM?
 
thenewwazoo said:
I'm not going to bother pulling examples from fuel maps, but the lower the RPM, the less fuel you use, in all cases. 100% throttle at x revs uses less fuel than 50% at 2x revs. Short-shifting is exactly the appropriate response for a feed forward-only fuelling system like carburation.
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OldFatGuy said:
So, holding the throttle at 6000RPM in neutral uses more fuel than climbing a mountain with a headwind at 5000RPM?
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Ooooooohh, you just got served! Although I think wazoo meant over the same terrain less rpms means better mpg.
 
nbean16 said:
Ooooooohh, you just got served! Although I think wazoo meant over the same terrain less rpms means better mpg.
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But he said lower RPM used less fuel in all cases.

The truth is, fuel maps are based on more than just RPM.
 
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Check out these crazy things I saw today...VW 1.6 L engines, automatic trannies
 

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Coasting downhill in neutral not only saves major gas, it's also a unique challenge that is very entertaining. Silence, wind only...
 
HappyHighwayman said:
Is that safe though in case you need to suddenly accelerate?
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You'll be doing a lot more braking then even thinking about throttle.

Besides, aside from fun factor, how often do you really need to throttle for safety, especially downhill?

Just try it. Not on a congested road, like front 9 or 84, but something like Alba or Tunitas Creek or Jamison Creek. It's a friggin hoot!
 
I regularly coast down woodside road behind hardbody nissans with no brake lights, or petrified white-knuckled greyhairs in crown vics, or NIMBY prius drivers. I wouldn't call it a hoot, but it helps relieve boredom.

(if you want to save gas, though, it's better to engine brake on an FI bike - the engine cuts all fuel on deceleration)
 
What they said, lay off the gas, coast as much as possible, use highest gears. Avoid quick starts. And the big one: slow down on the highway, wind resistance goes up as the square of the velocity. 65 mph is more efficient than 75. 55 is even better, but you can't do that on the slab.

According to the MSF, close drafting is a good way to get killed as they can go over obstacles that will take you down. Drafting 100+ ft behind a semi (where you have enough room to react) isn't so bad, but you lose some of the draft at that distance.

I wouldn't be surprised to see your mpg be half what it could be if you go from sport riding to gentle cruising for mpg.

But the only way to really know is to measure it.
 
HappyHighwayman said:
Yeah I should have , I had an opportunity. Totally my fault.

But we came from south towards Napa, not away from napa.
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Oops, my fault. I read it as going from Napa to Lake Berryessa.

Good thing you made it! I know my usual range is around 130 miles before my fuel light comes on. I prefer to top it off when I can, as someone who has run out of gas on the freeway before.
 
kurth83 said:
What they said, lay off the gas, coast as much as possible, use highest gears. Avoid quick starts. And the big one: slow down on the highway, wind resistance goes up as the square of the velocity. 65 mph is more efficient than 75. 55 is even better, but you can't do that on the slab.

According to the MSF, close drafting is a good way to get killed as they can go over obstacles that will take you down. Drafting 100+ ft behind a semi (where you have enough room to react) isn't so bad, but you lose some of the draft at that distance.
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On my car with trip-computer, 100-ft behind a semi @ 65mph (1.5-sec) gives a 10-15% increase in mileage. Not significant, but definitely noticeable. Didn't Mythbusters do an episode on this?
 
DannoXYZ said:
On my car with trip-computer, 100-ft behind a semi @ 65mph (1.5-sec) gives a 10-15% increase in mileage. Not significant, but definitely noticeable. Didn't Mythbusters do an episode on this?
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Drafting with a car and motorcycle are two different things. A motorcycle has a much smaller footprint. The dangerous move is to ride up into the low pressure formed directly behind the van. You can definitely feel it as it slowly sucks you in. YES, IT'S DANGEROUS AND A THROWING A RETREAD WILL END YOUR DAYS.
 
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