Saturday, June 09, 2007
Gain nearly 10 miles per gallon with just one simple change!
The passage of time. That's it. I haven't really changed my driving style or made any modifications at all to the bike between those measurements. I've been wondering a bit why my bike might be getting better mileage now too. Here's some possible explanations:
- School's out, so the traffic is not quite as thick.
- The gasoline blend may have changed, as they use different additives in summer and winter for emissions control.
- It's hotter, and this may improve gas mileage, particularly on an air cooled engine like in the GS500F.
- The bike only had 1,400 miles on it when I got it, so it may be a bit better broken in.
But I haven't made any mods to the bike at all. Suppose I had installed something a scam artist was selling claiming it improved mileage - let's call this imaginary rip-off the Whirlwind Wallet Waster. And suppose the device did absolutely nothing. If I'd put that on sometime in the spring, I might have attributed this huge mileage gain to it, and put some glowing testimony all over the Internet about how the Wirlwind improved my mileage, and how effective this thing is. But that testimony would be completely wrong - the bike has picked up nearly 10 mpg on its own without me actually doing anything.
If there's a moral to this, it's that gas mileage measurements are not easily repeatable. If you are trying to measure mileage changes from a modification, you need to rule out all other possible factors that may have caused the mileage change, as you can get very large changes in mileage - larger than the ones companies selling bogus mileage gadgets advertise, sometimes - without changing anything about your engine. If you're telling me something gave your car a huge improvement in mileage, it's up to you to prove the mod actually was responsible for the change, and that you've made an effort to prove this was not some other fluke changing the mileage that has nothing to do with the mod. Or worse, if you're getting more miles per tank but haven't checked how many miles per gallon you're putting in, can you prove to anyone that this isn't just an optimistic reading of your gas gauge?
With gas mileage able to bounce around like that on its own, it takes careful work to make sure a change actually improves mileage and it isn't some other factor at work.