How to Spot a Tampered Manufacturing Code on the Sidewall

Almost a decade ago, a person in China discovered that the tire manufacturing date was tempered with a brand new manufacturing date. He posted the relevant tools and procedure to modify the manufacturing date.

In the year 2020, a mass media published a news (the news is in Chinese) regarding counterfeit tire manufacture date. Drivers in China file complaint in forums and other online platforms regarding their recently purchased tires problems, including bulb appeared at sidewall or tire tread area.

A few posted self-made counterfeit manufacturing date. Comparing a genuine one, sometimes it is not easy to discover the fake one imprinted on it.

The consequences of fake manufacture date

Tire will deteriorate the moment it comes out from the machine. If the actual manufacturing date is some years ago, cracks may quickly appear at the tire sidewall after installation (as soon as within one week). In more severe cases, bulges appear on the sidewall or in the middle of the tire. In the worst case, the tire may burst suddenly without warning.

How to check

i. Background color of the manufacture date

Look at the background color of the date compared with the area around it. Sometimes, the area of the date has a very contrasting color.

ii. Area of the manufacture date

Normal tire normally have smooth surface without extruding background. A date MUST be printed on the tire right after it is created. It is the international standard procedure.

However, any date printed after it is created, it looks quite a bit, different.

Counterfeit date imprinted appear to be more extruding from the background. Furthermore, the area around the date appears to be grinded off.

After finding out these modification process, I realized that I came across these bogus date tires brought by other drivers in the past.
However, I still believe there is no counterfeit tire as it takes a lot of processing and tools to amend the surface of the sidewall. But fake tire date looks VERY common nowadays in the tire industry (more images below at case ii, will be uploaded soon).

If you found yourself with fake tire code installed, I strongly recommend replacing that tire asap.

Cases happen in Hong Kong

i. Manufacture date grind off

A number of years ago, a number of drivers came to the store for tire patch and discovered that their tire manufacture date is grind off by purchasing their second hand tire.

ii. Tire purchased from taobao online platform

The customer purchased two tires from taobao for his Sorento, 235/60 R18. The tires width and height appear to be smaller than his current tires. I should have taken more images of the two tires for comparison.

The above case is VERY common, coming from customers who brought their own tires for installation instead of purchasing from local tire stores. Just recently, there was another one who brought a set of tires for installation, and the date looks exactly the same as the first image shown above. The following will show more counterfeit and genuine date for your reference. (images will be uploaded within few days)

Michelin Tire

The tire’s production date does not blend with the sidewall. After reviewing all the genuine tire dates above, you will notice that the date in the picture above was printed on separately. Possibly that space was left blank after the tire was manufactured and the date was added later. It could also have been grinded and then reprinted.

When a baby is born on 1st Jan, 2025. The birth date is 1st Jan, 2025 but not 2nd Jan, 2025.
So as the tire when it comes out of the machine on 1st Jan, 2025, it should be 0125. The date should be imprinted at the sidewall together or, at least, should be printed on that day. The rubber date imprinted should be oxidized together with the tyre such that the color should be the same (especially if the date is printed together with the tire is created)

If the date is printed later on, there will be a color difference. You never know if the date printed is truly genuine date.