Recently Leslie contacted me about his web site, MyAutoLog; the site allows you to enter fill-up data from each time you fill your car (fuel cost, quantity and odometer reading) and generates loads of MPG data. The web site is stunningly well designed – even more incredible when you read that all of it is his own work!
I sent Leslie all the MPG data from GBMINI#2 and GBMINI#3 (I maintain an Excel spreadsheet) and he entered it all into his programs:
Leslie entered the before-JCW and after-JCW data for GBMINI#2 as two separate cars; the summary page for “GBMINI” (above) shows GBMINI#2 doing 11.9K miles before the JCW upgrade, at an average 27.80mpg; and 16.5K miles after, at a lower 26.76mpg.
GBMINI#3, with its automatic transmission, is averaging 26.95 on 7.5K miles so far.
More interesting perhaps is the ability to compare your car with everyone else who enters data; here for example I compared GBMINI#3 with all MCs, all MCSs and all JCW MCSs:
Now we can see that the average of all MCs is 32.08mpg (4.5K miles), the average of all MCSs is 25.99mpg (36.8K miles) and the average of all JCW MCSs is 25.15mpg (14.4K miles).
We need more MC owners to sign up to MyAutoLog!
Sadly Leslie has not yet got charts working (like GBMINI#3’s MPG chart); also the way he calculates the MPGs (dividing the latest miles driven by the previous tank of gas) is, in my mind, wrong and generates erroneous MPGs, especially if some of your fills are at significantly different distances apart.
For example his calculations claim a best MPG for GBMINI#2 of over 59mpg! This is caused by filling up the tank before a long drive (so only a small fill), then driving a long way before the next fill (so a large distance).
I always calculate with the latest distance divided by the latest fill, which is more accurate assuming (as I do) that I always fill the tank to the top.
However none of this detracts from the very useful averages and comparisons with other cars.