Lude Generation

Thought the sensationalist headline might grab your attention

Anyway, I have the Road Trip Lite App for I-phone which i have been using as a guide to calculate my MPG figures. I realise that it is not gonna be super accurate, but something i have come across doesn't make sense to me.

So, you enter your fill up details, odometer reading, litres, price, total£, and it calculates your MPG for you. Sounds pretty cool? (If you just enter price and litres it auto calculates cost, or if you just enter cost plus price, it auto calculates litres etc)

One day i was entering my details and i noticed that i had entered the wrong amount of fuel. (I had entered £200, but had only put in £20). But what i did notice was the MPG figure changed when i amended the amount.

Now, surely by entering the wrong amount, only the next MPG calculated would be wrong. The cycle i had just completed should be unaffected

Please confirm that my brain does in fact work

I also noticed that if i played about with any of the numbers on my new fill up, the previous MPG changed

I realise that this is the free version of the App and wondering if the full version might be different, but i don't fancy giving them £1.79 to find out

This also goes some way to explaining the 9MPG run i did a few months ago

I think they use your current fill up to calculate the fuel used in the previous cycle, is that not what it's doing??

Ie. the amount you just filled up, is actually the amount you've used since the mpg was calculated at the previous fill up - same as if you do what I do and calculate it on the fly

I use the full version! Been using it since October 2012 and its been really accurate! In town I average around 20mpg but on the way to Birmingham on the long trips its 36+ mpg.

I'll drive and get a screenshot later on!

Really good app, it shows you how much money you have used to full up. So far, from October till now I've used £475 on fuel.

I suppose i could get round this by putting the same quantity in each time?

Or just man up & get the full version

Just use this: http://www.fuelly.com/

If you go to it on your phone, you get a nice web interface. Cost £0.00.

I have an iPhone so I have the AccuFuel app, and I enter in litres and miles off the trip counter, and it just works out what I did mpg wise on that tank of fuel. It's always retrospective, as it can't predict what mpg you'll do on your next tank of fuel