Buying tyres without ever touching one
Tyres are one of the few car parts most people now buy online rather than at a garage counter, often paired with a mobile fitting appointment. The saving can be real, and a voucher code or coupon code from the retailer can push the price down further, but only if the tyre ordered is genuinely the right one. Getting a size or rating wrong is not a small mistake on a part that carries the full weight of the car and is the only contact point with the road.
Reading the size code on the sidewall
Every tyre carries a printed code such as 205/55 R16 91V, and each part has a specific meaning.
- 205 is the tyre width in millimetres, measured tread edge to tread edge.
- 55 is the aspect ratio, the sidewall height as a percentage of that width.
- R indicates radial construction, the standard method used on almost all current passenger car tyres.
- 16 is the rim diameter in inches that the tyre is built to fit.
- 91 is the load index, a code number linked to the maximum weight the tyre can carry per tyre.
- V is the speed rating, a letter linked to the maximum speed the tyre is rated for.
The safest approach is to match this full code to what is already fitted or to the specification in the vehicle handbook or on the sticker usually found inside the driver's door frame, rather than guessing from memory. A tyre with a lower load index or speed rating than the vehicle requires is not simply a minor compromise; it falls outside the tyre's approved use.
The EU tyre label
Tyres sold in the EU and the UK carry a label covering three measured properties: fuel efficiency, wet grip and external rolling noise. Fuel efficiency and wet grip are each graded on a scale from A, the best, down to E. Noise is shown differently, as one, two or three sound-wave bars corresponding to three classes, rather than a letter. Since the label was updated in 2021, it also carries a QR code linking to an EU product registration database, so the same figures printed on the label can be checked online against the manufacturer's own registered data. The label says nothing about tread life or handling in general, only these three specific, tested properties, so it is one input among several rather than a full verdict on the tyre.
The DOT code and how to check a tyre's age
Alongside the size code, tyres carry a DOT code ending in four digits, for example 2324. The first two digits are the week of manufacture and the last two are the year, so 2324 means the 23rd week of 2024. This applies to tyres made from 2000 onward; earlier three-digit codes are effectively obsolete on tyres still in use today. Age matters even on a tyre that has never been fitted, because rubber compounds harden slowly over time regardless of mileage, which is why checking the DOT code on a newly bought tyre, not only on old ones being replaced, is worth the ten seconds it takes.
Matching new tyres to the rest of the set
Fitting a single new tyre next to three worn ones can affect handling, particularly on vehicles with four-wheel drive, where a difference in tread depth between axles can put strain on the drivetrain. Where budget allows, replacing tyres in pairs on the same axle, keeping similar tread depth and, ideally, a similar tyre type, avoids this. This is a mechanical consideration rather than a legal one, and requirements vary by vehicle, so checking the handbook or asking a fitter when in doubt is more reliable than a general rule.
Ordering online and getting them fitted
Most online tyre retailers offer either delivery to a home address for fitting elsewhere, or delivery direct to a local garage or a mobile fitter who comes to a chosen location and address. Booking the fitting slot at the same time as the order usually avoids tyres sitting around waiting for an appointment. Fitting itself includes mounting, balancing and fitting a new valve, and a reputable fitter will also dispose of the old tyre through a proper recycling route, which is worth confirming if it is not stated up front.
Returns, guarantees and the legal side
In the EU and the UK, distance selling rules generally give a right to change your mind on an online order within a set period, but this right is commonly lost, or limited, once a tyre has been fitted and used, since a mounted, driven tyre is no longer in its original condition. A separate right applies to tyres that are faulty or not as described, which is a matter of statutory guarantee rather than a change-of-mind return, and runs alongside any manufacturer warranty on materials or workmanship. In the US, return rights are set by the individual retailer rather than by a general federal distance selling law, so the seller's own stated policy is the reference point. In every region, checking the retailer's return and fitting terms before ordering, rather than after a problem appears, avoids most disputes.
Checking for a code before ordering
Tyre prices vary between retailers for the same size and rating, and a voucher code can apply on top of an already competitive price, particularly around seasonal changeover periods when many drivers switch tyre types at once. We list current codes across 527 shops in 22 countries, checked several times a day, without requiring an account. Current listings for vehicle-related retailers can be browsed under Auto & Vehicles, or under the equivalent US category for buyers ordering from a US-based retailer.
Frequently asked questions
What does the speed rating letter on a tyre actually limit?
It states the maximum speed the tyre is rated to sustain under proper load and inflation conditions. Fitting a tyre with a lower rating than the vehicle requires means the tyre is being used outside its tested range, regardless of how the car is actually driven.
Is a tyre with a good EU label automatically the best choice?
Not necessarily. The label reports fuel efficiency, wet grip and noise only, tested under standard conditions. It does not cover dry handling, tread life or performance in snow, so it is useful alongside the size and rating requirements rather than a replacement for them.
How old is too old for a tyre that still has plenty of tread?
There is no single legal age limit that applies everywhere, and tread depth is not the only factor, since rubber can harden with age even without heavy wear. Many manufacturers suggest reviewing tyres for age-related wear after several years in service; checking the DOT code and having a fitter inspect the rubber is more reliable than judging by tread alone.
Can a voucher code be used together with a fitting service?
That depends entirely on the individual retailer's terms for that promotion. Some codes cover the tyre price only, others apply to the combined tyre and fitting package, so checking what the code applies to before completing the order avoids a surprise at checkout.
