How to...

Initial setup

After installing my cars, a default car has been created with the name "My car". You can change the name of the car. Got to cars tab and click on the "My car" name.

But most important thing is to first check that the units used by my cars fit your locale. Go to preferences and check units.

Example car settings:

- car odometer reading was at 20'000 miles the last time you did a refuel

-> initial mileage = 20'000

- your last refuel (not entered in my cars) was not a full refuel, hence the tank was still partially empty

-> init state is with full tank = unchecked

- you have a new car, hence usually you don't know how much fuel is in

-> init state is with full tank = checked

- you know that you already spent around 3000 $ in your car expenses like insurance, etc... without knowing the details

-> initial cost = 3000 $

- when you bought your car the mileage of the car was 15000 miles (second hand car)

-> car purchase init mileage = 15'000

- you bought the car at a price of 12'500 $

-> car price = 12'500 $

- your car has a tank size of 30 gallons

-> tank size = 30 gallons

- your car use gasoline as fuel

-> fuel = gasoline

- the preferred fuel subtype is "Super diesel". This value will be set by default for each refuel. The fuel subtype is fully customizable

-> fuel subtype = super diesel (use admin button to add it)

Car details data:

A screen with the vehicle options is displayed.


When you refuel you need to enter at least the odometer or trip distance value. It's obviously recommended to also set the fuel quantity in order to have fuel effiiciency computed. Fuel price will also be useful to track price history.

- odometer being the total distance covered by the car (like 120'000 miles/km)

- trip value being the distance covered since last refuel (or journey)

You can switch the default distance mode in the preferences, but you can also switch in the refuel screen by clicking on the distance label/button.

What about the inital refuels? Let's take a sample

initial mileage = 10'000 km

refuel 1 = 10'500 km / full / 30 l

refuel 2 = 10'700 km / partial / 10 l

refuel 3 = 11'100 km / full / 25 l

Type of refuels

    • Full refuel:

      • to be used when you fill-up the tank.

      • Do not forget to set the distance and quantity if you want the entry to be included in fuel efficiency stats.

      • Fuel price is needed for cost stats

    • Partial refuel:

      • you didn't fill-up the tank (for instance because the fuel was too expensive), so no problem, just tell my car that this is a partial refuel.

      • If next refuel is a full refuel, then My Cars will compute the average fuel efficiency of both entries.

      • You could also use several partial refuels before having 1 full.

      • In all this cases the fuel efficiency stats will be updated when you will enter a full refuel.

    • Partial refuel with gauge:

      • Only available if the tank size has been set for the vehicle

      • The idea is that you also put what is the quantity left before or after the refuel based on gauge reading

      • Needs to have at least 1 full refuel prior the use of partial refuel with gauge in order to have fuel efficiency computed

    • Missed full refuel:

      • to be used when you have no idea of the quantity of fuel you have entered.

      • Can be when you lend your car to a friend that doesn't car about stats :-). So when you take the car back and do a full refuel, just flag the refuel as missed and just enter the total distance missed.

    • A missed refuel must always be a Full refuel but based on an unknown state (distance and/or fuel quantity).

    • Missed partial refuel:

      • to be used when you have no idea of the quantity of fuel you have entered.

      • Same as missed full refuel but when you do a partial refuel

      • Fuel efficiency will only be computed after 2 full refuels

Fuel efficiency

1) Fuel efficiency is computed based on the current refuel data:

    • Distance = 500 miles

    • Fuel quantity = 20 gallons

    • Fuel effiency = 500/20 = 50 miles/gallon

Some users find it more logical to display the fuel efficiency on the previous refuel. The argument for that being that the fuel used to cover the 500 miles was from previous refuel.

My Cars "only" supports displaying it on current refuel because:

    • it's the prefered options of vast majority of users

    • displaying it on the previous refuel doesn't always refuel the correct fuel used. For instance if we refuel often medium quantities the fuel really used is made of several past refuels

    • My Cars provides a Records tab that include all details of what type of fuel was used for the 2 best/worst refuels per vehicle.

My Cars will probably support the option of having the fuel efficiency displayed on previous refuel, but it's not a top priority on the todo list.

2) There is often a second mis-understanding from some users. The question is why My Cars is using the quantity of current refuel to compute fuel efficiency. The answer is because if on your previous refuel you did a full refuel, then if on the current refuel you do again a full refuel of 10 gallons and that you covered 100 miles, it means you really "burned" 10 gallons to travel the 100 miles.

Perhaps an easy way to understand this is through a simple example considering the tank was full before the first trip.

Refuel 1:

    • Fuel refuel

    • 400 miles

    • 10 gallons (Fuel brand 1)

Efficiency = 400/10 = 40 miles/gallon

Refuel 2:

    • Fuel refuel

    • 40 miles

    • 1 gallons (Fuel brand 2)

Efficiency = 40/1 = 40 miles/gallon

Here if we would have used previous fuel quantity we would have had: 40/10= 4 miles/gallon.

Refuel 3:

    • Fuel refuel

    • 400 miles

    • 10 gallons (Fuel brand 3)

Efficiency = 400/10 = 40 miles/gallon

Here if we would have used previous fuel quantity we would have had: 400/1= 400 miles/gallon.

Fuel efficiency with partial refuels

In order to provide a good computation of fuel efficiency we require a full refuel.

However as some users only use partial refuels, My Cars provide also a way to estimate fuel efficiency for partial refuels.

The idea is that My Cars will compute partial refuels efficiency after you have used x partial refuels in a row that have accumulated more than y times the tank size. Y is a parameter in settings/refuel.


- tank size = 40 litres

- settings/refuel/partial fuel efficiency factor=2 (default is set to 5)

- First partial refuel with 30 litres -> no fuel efficiency as 30<40*2

- Second partial refuel with 30 litres -> no fuel efficiency as 60<40*2

- Third partial refuel with 30 litres -> fuel efficiency computed as 90>40*2


- Feel free to adjust the factor y to accomodate your needs, but a value less than 3 is not recommended

- The global fuel efficiency will not be affected by this, as at then end we will use for instance all yearly fuel quantity and distance. This setting will mainly allow you to have intermediate estimates.

Multiple currency support (PRO only)

My Cars provides support for multiple currencies at same time. For instance you could leave in USA, and hence have your base currency is USD. But you could enter for instance a bill in EUR.

Multiple currency support is available in all fields with an amount.

By default you will always have the default currency selected for all amount fields.

Changing the currency of an amount will show you all other available currencies. You will then have to press the refresh exchange rate button. If you would like to download automatically the exchange rate, please go to settings/exchange rates.

My Cars is able to download exchange rates for any of the following currency pairs:





Historical rates are included since 1999.

For all other rates you will need to enter the rate by yourself.

There is also the possibility to set an exchange rate spread. If the spread is 0%, then My Cars will use the Spot rate


- USD/EUR spot rate = 0.73

- Spread = 0% -> My Cars will use 0.73

- Spread = 2% -> My Cars will use 0.7446 if you buy something (like a refuel) or 0.7056 if you sell something (negative bill)

The spread includes bank & credit card taxes

You can change the spread in the settings.

Updating default currency

You can also update the default currency in the units. With PRO mode it will ask you whether you would like to update all amounts against the new currency.

For instance the old currency was CAD (Canada), and now you would like to use USD.

If you refresh all exchange rates, then My Cars will apply the exchange rate CAD/USD on all the amounts. You will always have the original currency and amount stored.

In case of any doubt on this topic, please contact support.

Exchange rates settings

Import data (XML/CSV)

CSV import: (easiest)

Easiest way to import data is through CSV format. Recommended procedure:

1) first set-up all your preferences in my cars

2) fill one record per type you want to import (for instance 1 refuel and 1 maintenance record)

3) export your data in csv format

4) extract the part about your entity in another csv file, and leave only the columns you are interested in.

For instance refuel.csv:

#entity: refuel


"My car","2010-11-10 10:10","35.5","32500","1.12"


- #entity: refuel must be kept

- ##car_name, .... describes the column names. Please make sure you type correctly the names

- separator of decimal must be: "."

- date format is: yyyy-mm-dd hh:mm

For the time being the import errors are not clear. I will work on this to ease complex imports. Should you have any problem with import please contact me.

XML import: (for experts)

You can import data through an XML format. Nonetheless before trying to import, you should first check in the preferences that my cars is using the units you want to (miles/kms, etc...).

Then you can create for instance a "dummy" refuel and use export data feature (menu admin) and you'll see a file in the folder mycar of your sd card. Then you should use this syntax to fill your records.

If you already have data in an Excel sheet, no worries, you can export it using Microsoft Excel 2003. To do so:

- open your excel file

- use the file you exported with my cars as a XML model (-> menu data\xml)

- then map all your columns from the XML model to your rows. Please note that the dates must have the following format: yyyy-mm-dd hh:mm -> example 2009-11-22 15:45

- export xml through menu data\xml\export\mycar_data.xml

- review your file (start and end) to see if something looks wrong

- copy the file to your sd card in the folder mycar

- use import feature of my cars (menu admin)

Restore data from a backup

On every change, My Cars auto-backups your data to SDCard in the folder sdcard/mycar. It keeps by default a history of 10 backups.

If you use the PRO version (PRO key, or by enabling ads), you will also have your data automatically saved to your Dropbox under the folder applications/My Cars. Please note for time being the pictures are not yet saved in Dropbox

Backup on SDCard:

-> The last backup file is: sdcard/mycar/mycar_data.xml

-> The previous backup files are: sdcard/mycar/mycar_dataxxxx.bak (xxxx being datetime of the backup)

Use case 1: restore data on new phone using SDCard

To get back your data, here is the procedure:

1) Create a copy of the sdcard folder mycar.

2) Install My Cars on the new phone

3) Copy the folder mycar to your new phone (at the root of the sdcard, in order to have a folder sdcard/mycar)

4) Disconnect your sdcard from your computer (if you use a computer to rename the file)

5) Start My Cars

6) Go to Import/Export Menu by cliking on top left icon. Select mode=Full Import and target=SD Card as shown in picture below

7) Check that the file name with correct path/directory exists -> File must not be null, but have mycar_data.xml.

8) Press on the button "Start"

Import screen: here the SDCard path is /storage/emulated/0/mycar (Nexus 4). Make sure you have your file mycar_data.xml in that folder.

After the import, you should see a screen with the number of items imported. Double check that the number of refuels is greater than zero.

Possible issues in import:

- On some phones there are several sdcards folder. One internal, and the other external. If the import fails (check 7)), then try to use a file explorer like ES Explorer in order to copy the you copied from the PC to the folder displayed in the import screen.

- If you had 2 bill type categories with same name, the import will fail. This use case is not allowed. I will make sure I fix this for a next release

- I am currently investigating issues on some phones with very large number of data (>900 refuels).

- If you have any other issue, please send me an e-mail

Use case 2: restore data on new phone using Dropbox

In this use case by default your file is already in your Dropbox (\Dropbox\Applications\My Cars\mycar_data,xml)

To get back your data, here is the procedure:

1) Install My Cars on the new phone

2) Install My Cars PRO Key (or launch My Cars and enable PRO mode with Ads)

3) Start My Cars

4) Go to Import/Export Menu by cliking on top left icon. Select mode=Full Import and target=Dropbox as shown in picture below

5) Click on authenticate (this should start the authentication process against your Dropbox for My cars folder access )

6) If you didn't use Dropbox before, please copy manually on your PC(MAC the file mycar_data.xml to folder (\Dropbox\Applications\My Cars)

7) Press on the button "Start"

After doing the import, the status should show something like:

Use case 3: you have resetted your phone

Depending on the phone model a hard reset can result in full erase of the SDCard content. Hence eventually loosing also your backups. If that's the case, I would suggest to try to use a tool to restore deleted files on your SDCard, or to try to restore the Google online backup with followin procedure:

Bi-fuel cars managment


Bi-fuel vehicles are vehicles with multifuel engines capable of running on two fuels.

On internal combustion engines one fuel is gasoline or diesel, and the other is an alternate fuel such as natural gas (CNG), LPG, or hydrogen.

The two fuels are stored in separate tanks and the engine runs on one fuel at a time, unlike flexible-fuel vehicles ("dual-fuel"), that store the two different fuels mixed together in the same tank, and the resulting blend is burned in the combustion chamber.

Bi-fuel vehicles have the capability to switch back and forth from gasoline or diesel to the other fuel, manually or automatically.



First of all My Cars supports 2 different uses of bi-fuels cars in order to compute what distance should be considered for fuel efficiency computation. The setting can be changed in the preferences

Preferences/ Bi-fuel:

- same refuel type: use this option if you mainly use LPG/CNG and only use petrol for the start-up of the engine. And you still would like to have a figure on how much the fuel usage is, meaning it will be quite low.

- on last car refuel: use this setting if you use quite often both fuels. It means every time you do change of fuel you have to write down the distance covered. Obviously when using this option the fuel used at start-up won't be computed, but I believe the error will be low.

I also recommend to start using My cars with both tanks full. If one of them is not full , please un-select the option in the car that tells if the initial state is with a full tank. In the future I might add 2 options for this, one for LPG/CNG and another one for gasoline/diesel.

Preference: Same refuel type

Use this option if you always use CNG/LPG. Gasoline/Diesel will always be slighly used in order to help on start-up of the engine.

With that option you will be able to see how much gasoline/diesel you use. Obviously the fuel efficiency for that fuel will be quite low, as you will mostly use CHG/LPG.

Preference: On last car refuel (preferred option)

So let's imagine you start using your car on gasoline. You drive 100km, and then you then would like to change to LPG

1) Add Refuel -> 100km / Gasoline / Partial (without quantity). Use partial even though you don't fill anything, but that way My Cars will know you change of fuel type

Then after 200km we stop at a petrol station and we do a full refuel of gasoline (40 litres). Here we must enter 2 "refuels". One for telling we change of fuel with the distance covered. And the second one for the actual quantity filled on gasoline, even though not used during last trip.

2) Add Refuel -> 200km / LPG / Partial (without quantity) (this means we drove 200km on LPG)

3) Add Refuel -> 0km / Gasoline / 40 litres / Full (this means we just did a refuel, but we didn't drive on gasoline) -> fuel efficiency will be computed based on the distance of 1)

In a future release I will probably ease this use case by only needing to enter 2) and 3) in one screen.

!!! Please note that any release <= will not cover well this use case. A fix is implemented in next release !!!!

Google online backup

Starting with release 1.8.2 there will be by default a automatic Google Online Backup. The local backup on SD Card will still work. The backup will only be used if you init your phone or install My Cars on a new phone. Then after the re-install you will have again your data for free. No need to import or anything :-)

However it's not guaranteed that the Google Online Backup will work on your phone. You need mainly 2 conditions:

- a phone running Android greater than 2.2

- a phone carrier that would support online backup. I cannot tell which ones support the feature

- For ICS (Android 4.0) users, please check Android preferences in section Backup & Reset. Make sure the Backup my data is enabled.

If you go to the preferences, and in the section Data backup, you will see the last online backup date. This date probably means your data has been backup online, but once again not yet guaranteed.

Once I will collect some statistics I will give you more infos on this feature.

In the meantime please still consider the local backup on the SD Card as the main backup. I recommend to keep a copy out of your SDCard also.

Please give me feedback about this feature, in case of problems or success!

Global stats

The main screen of My Cars includes several statistics. You can filter by vehicle or by time range.


A reminder can be set for a maintenance record for instance. You can set a reminder based on 2 values:

    • time (every x year, x month, or x day)

    • distance (every x miles/km)

If both are set the reminder will be effective when the first is reached.

For instance you can set a reminder for a "Major service" every 6 months or 10'000 miles/kms

A page summarize all the reminders with the expected dates. In order to access the reminder page you need to press on the clock icon below the tabs on the right.

By configuration you can enable notifications. If set you'll have a notification that you can acknowledge or snooze.

Reminder types:

    • maintenance reminders (oil change, tyres pressure, etc...)

      • time and/or distance

      • first reminder is on the earliest of frequency start or distance start

      • next reminders will always take the last maintenance record as a basis adding the frequency distance and time. For instance last oil change at 10'500 miles + 6 months or 5000 miles

    • bill (insurance, etc...)

      • time.

      • a bill is more seen as a regular event, hence my cars doesn't use the last bill to estimate the next one.

    • other reminders (anything not related to maintenance or bills)

      • time and/or distance

Events screen:

    • a value in red means the reminder has passed without any entry (no bill/service recorded)

    • if OK is displayed next to the value in red it means you have acknowledged the reminder, but still haven't recorded the corresponding bill/service.

    • service reminder

      • first line -> expected date and distance based on respective frequency

      • second line -> expected completion date (earlier date based on distance or frequency)

      • example

        • Audi A3: 20-06-2016 | 25'000 km

        • -> 20-06-2016 (if that date would be reached before the 25'000km)

        • -> 30-09-2015 (if 25'000km would be reached on 30-09-2015, hence before time frequency date)


    • It's best to use reminders on a per vehicle basis

    • Adjust reminder global settings to adjust time of day for notifications, number of days before notification, and notificatio snooze duration