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How to Document your Car

Documenting your classic car is an important part which is often neglected and the last thing to do in a seemingly endless list of to-dos. According to the CEO of The Motor Chain, a poorly or not documented car will affect its value and trustworthiness and can lead to a 10 - 20% price decrease on the market. A well-documented car will also make life easier when selling it. There are over 450'000 cars sold with fake mileage. Consistent documentation will prevent fraud. Documentation helps with the decision if the seller can be trusted and if the car is legit. But it's not just important when buying or selling a car. Documentation also preserves the history of a car. This is especially true with historical, vintage and classic cars where we are just custodians. If we take good care of them they will hopefully outlive us. We are part of its history which should be honoured by diligent documentation.


Log Book Fuel Consumption
Logging fuel consumption and mileage in a Log Book

The 4 Levels of Trust

According to The Motor Chain, a digital car documentation management system, there are 4 levels of trust when documenting a car:

  1. The car has been documented by owners AND third parties with supporting evidence

  2. The car has been documented by owners with supporting evidence

  3. The car has been documented by owners with no supporting evidence

  4. There is no documentation


Garage WHS is using a digital documentation system
Garage WHS is using a digital documentation system to add supporting evidence

The Most Important Documents

All documents are important but do have different relevance. There are primary documents which identify the car and secondary documents that are produced during the life of the car.

Primary Documents


1st Category: These are original documents from the manufacturer, or an authorised seller of the car when it was new. They are original and cannot be duplicated. This includes information that was stamped or affixed to the vehicle by the manufacturer when it was new, for example, the VIN or chassis number. 2nd Category: Documentation from a recognized and trusted source that has access to the original vehicle documents and/or specifications and will formalize this information into a report specific to that vehicle.

Car Documents
Documenting a car with a digital app

Secondary Documentation


These documents might include previous titles or registrations, maintenance and repair receipts, inspection receipts, maintenance logs, period photos, certifications and awards, race logs, appraisal, photo documentation of restorations, and just about anything else that would apply to the car.

DB6 Booklet
DB6 owner with a little booklet for every year since 1966

Remind the Garage to Document

The garage plays a crucial part in the documentation of your classic car. Garages often do not sufficiently document the work and all details of the car. Make sure your garage gives you an official document that contains the following information when work or an inspection was performed:

  • Mileage and date on all invoices

  • A detailed writeup on the work

  • Replaced parts

  • Inspection points

  • Detailed cost of all items

  • Name of the mechanic who performed the work

  • Photos of the work


Stacked wheel balancing weights

Should you Document the "Do it Yourself" Work?


Always take notes of every work performed on the car. This will build the case and give consistency to the history of your classic car. Here are a few tips:


  1. Note the mileage and the date

  2. Take photos before you start the work

  3. Keep all spare parts invoices and/or emails

  4. Take photos of the relevant new parts

  5. Take photos during the work. Split into phases

  6. Take photos of the final result. The "after"


Static vs Dynamic Wheel Balancing

When documenting your car, keep all receipts and documents organised in a folder. We have seen already classic car owners who have several binders full of documentation from the last decades. Every piece of paper was collected and filed in the folder. In order to track gas mileage, fuel consumption and repair as well as maintenance events we put together a comprehensive Auto Log Book. You can keep a detailed and full record of all operational, maintenance and repair events on your car which you can carry in the glovebox.





Documenting Daily Events


Many companies require their employees to document every mile driven with the date, odometer reading fuel filled and where the car was driven to. This is especially important if the car is shared by multiple employees. Granted, this is not the accuracy and detail a private individual should do to document its car but it can be a great idea and benefit to document the car's fuel consumption by logging each filling. When logging your fuel consumption you know how much you are using and if the car is running within its parameters. When you go to the gas station to fill your tank, always reset your trip odometer. With the next fill, read the km/miles and take note of the gas volume you filled in the tank. Then calculate the gas mileage consumption. Do this every time you are at the gas station and take a note. You can also check fluid levels such as the engine oil, coolant and brake fluid every so often to monitor its health and consumption. Over time you get a feeling for your car's average gas mileage and oil/fluid consumption. If the fuel consumption suddenly increases, you know your car has a problem such as a fuel leak, bad spark plugs, clogged particulate filter or air filter, worn piston rings, faulty air mass sensor, leaking injectors, etc. Problems with the engine oftentimes result in worse gas mileage and are the first telltale of something going bad. A professional car owner should always know his average fuel consumption. If you don't want to create your own or buy a logbook, you can use our free Fuel and Maintenance Logs. We created a Google Sheets template to log the fuel consumption, average cost, as well as repair and maintenance events which you can download for free here: Fuel and Maintenance Logs




Document your Car Digitally


Documenting a car digitally can be a big challenge since paper is still more secure than computer file systems and hard drives. A computer or phone often breaks, gets missing or experiences a data loss. This is very annoying and makes digital documentation very unreliable. Fortunately, there is an app which documents the car's history on the blockchain (a secure and private cloud data management system) and safes them immutably as well as securely. The Motor Chain is a digital document management system based on the blockchain which can be accessed via a simple-to-use app or web interface. All details such as the VIN, services and repairs are saved immutably. TMC allows owners to authorise garages, certifiers, consultants, appraisers and other 3rd parties to participate in your car’s documentation, increasing the trust in the vehicle's history and letting you even seamlessly transfer the documentation in case you sell the vehicle. The Motor Chain is completely private and every profile is verified. The app was developed and programmed in Switzerland. You can sign up for a free trial with the link below.

The Motor Chain - A Digital Documentation App
The Motor Chain - A Digital Documentation App


When signing up to the Motor Chain, use our partner code: EVC8


Don't want to upload all documents yourself? TMC is coming onsite to register the car on the Motor Chain and will do a professional scanning of all documents. Send us an email to discuss options and plan the documentation process.



Nils Willner


Nils is a Swiss-German engineer who is obsessed with old cars and engines. He is the author of "The Ultimate Classic Car Guide - How to Buy, Maintain & Repair Classic Cars" and the founder of EVC. His passion has always been with old cars and everything that has wheels and an engine.