Partial fuel-up Issue
 

Just accidentally clicked the "partial fuel-up' check box on one of my fuel-ups and disaster...
All subsequent fuel listings were changed to "partial" despite editing each by unchecking the box. No matter which one I change (and I changed all of them) the update doesn't work. All the mpg readings are zero.

Anyone else experience this or did I discover an unknown bug?

Sounds like an unknown bug, but we'll fix it up after the long holiday weekend and get your data back in line. Sorry about the mix up.

In an effort to get more accurate data, we started automatically marking fuel-ups less than six gallons partial because they're not close to a full tank. You can see in your fuel-up list that only those fuel-ups less than six gallons are automatically marked partial. So as we developers like to say, it's a feature not a bug.

Yeah, were those fill ups really filled to the top in just a few gallons? Were you getting gas when your tank was more than 1/2 full?

Also, keep in mind even if readings on partial (less than all the way back to F) fuel ups aren't showing mpg, they are figured into the average mpg for your car. We still total up all the miles driven and gallons of fuel purchased.

pb - maybe this is why I'm not getting mpg calculated after my last fillup - it was only 4.0 gallons. Since my entire tank only holds 6.1 gallons, I've never put much more than 5 gallons in, and usually a fillup for me is in the 4 to 4.5 gallon range. Do you have some way of turning off this "feature" for motorcycles?

We ended up turning off the six gallon auto-partial for everyone so we're relying more on people checking the partial option. It wasn't transparent enough, and was understandably confusing.

It looks like your recent fuel-ups don't have an individual MPG calculated because you checked that partial option. Once you check that option, Fuelly skips calculating MPG on an individual fuel-up for that one and the next. And that's a good thing! It means your stats will be more accurate than if you hadn't checked that box. Partial fuel-ups do count toward your overall average MPG. Here's the FAQ about partial fuel-ups which has a little more info.

I read the FAQ (thanks for the quick reply, but don't understand why the next fillup isn't counted. As I see it, the calculation is fairly simple:

last fillup, miles1, gallons1 - mpg calculated

partial fill, miles2, gallons2 - no mpg

fillup, miles3, gallons 3 - you can now calculate mpg by (miles3-miles1)/(gallons2+gallons3)

I tried one of your competitor's sites and at the time they didn't have a partial fillup option, so I just did this manually and it worked just fine. I've done this for years in a paper log I keep in my glove box - I just mark fills and not fills, and when it is time to calculate mpg, I just add all the interim partials to get the total gallons used between fills.

Actually DMCox, after your third fuel stop, the calculation would be:

(miles1+miles2+miles3)/(gallons1+gallons2+gallons3)

It's just that for your partial tank, we don't display what the MPG is to you, because they can be wildly different (150mpg is possible as is 2mpg). But we calculate overall MPG by simply totaling all your miles and all your gallons, and it will become stable after a handful of fuel ups.