Tire date code and size decoder

The last four digits of the DOT code on a tire’s sidewall are its date of manufacture: week, then year, so 2321 means week 23 of 2021. The size, such as 245/40R19 98Y, gives the width, sidewall height, wheel size, load index and speed rating. Type yours below to decode them, from the tire technicians at Prestige Auto Repairs & Tires in Oakland Park and Fort Lauderdale.

Last 4 digits of the DOT code

Enter the four digits after the DOT code, for example 2321.

Tire size from the sidewall

Enter a size like 245/40R19 98Y or 225/45ZR17 94W.

Book a tire check (954) 303-0758

How to read your sidewall

Find the size in large print, for example 245/40R19 98Y. It is also on the placard in the driver’s door jamb.
Find “DOT” followed by letters and numbers. The last four digits are the date: week, then year. Tires made before 2000 used three digits.
Check both sides. The full DOT code is often only on one sidewall, sometimes the inner one.
Look for cracks, bulges and wear bars. Tread at 2/32 inch is worn out; on wet South Florida roads grip drops well before that.

Common speed ratings
Letter	S	T	H	V	W	Y
Max mph	112	118	130	149	168	186

Common load indexes (per tire)
Index	91	94	98	100	103	107	110
Pounds	1,356	1,477	1,653	1,764	1,929	2,149	2,337

Tires at Prestige

Heat ages tires faster here

South Florida sun and hot pavement dry out rubber, so a tire with plenty of tread can still be too old. At both shops we read the date code, measure tread on every tire, check for cracks and bulges and set pressures, and show you photos before you decide. See our Oakland Park tire shop, tires and alignment in Fort Lauderdale and our guide to choosing tires for South Florida heat.

Buying a used car? Tire age is one of the first things our pre-purchase inspection checks.

How do I find the date on a tire?

Look on the sidewall for the letters DOT followed by a code. The last four digits are the date: the first two are the week and the last two the year. 2321 means the 23rd week of 2021. The full code is often printed on one side only, so check the inner sidewall too.

How old is too old for a tire?

Rubber ages even when the tread looks fine, and heat speeds it up. Many vehicle and tire makers advise replacing tires around 6 to 10 years after they were made, whatever the tread depth; check your owner’s manual and the tire maker’s guidance. In South Florida heat we look closely at any tire over 6 years old for cracks and bulges.

What does 245/40R19 98Y mean?

245 is the width in millimeters, 40 is the sidewall height as a percentage of the width, R means radial construction, 19 is the wheel diameter in inches, 98 is the load index (1,653 lb per tire) and Y is the speed rating (186 mph).

Can I put a different size or rating on my car?

Stay with the size, load index and speed rating on the placard in the driver’s door jamb unless a specialist confirms an alternative. A lower load or speed rating than the original can be unsafe, and on all-wheel-drive cars all four tires need to match closely in diameter.