How to Read Tyre Size: What the Numbers on Your Tyre Mean

205/55 R16 means a tyre 205 millimetres wide, with a sidewall 55% as tall as it is wide, of radial construction, made to fit a 16 inch wheel. It is one of the most common car tyre sizes in the UK, found on many family hatchbacks and small saloons.

The sidewall on a 205/55 is about 113mm tall. That is a middle profile, a fair balance between comfort and sharp steering. After the size you usually see a load index and speed rating, often 91V or 94V on this size. 94 is often an XL version for heavier cars, and it is the one to choose if your car came on it. 205/55 R16 tyres shows the options we fit in this size.

Other very common sizes include 195/65 R15 and 225/45 R17. See 195/65 R15 tyres and 225/45 R17 tyres. Whatever your size, call 0300 124 6981 or send it on WhatsApp and we send back a fitted price, with no call out charge added. Common sizes like these are usually on the van, so the tyre can be fitted on the same visit rather than ordered in.

The first number on a tyre is the width in millimetres, measured from one sidewall to the other. In 205/55 R16, the tyre is 205mm wide. Most car tyres fall between about 155 and 255. A wider tyre puts more rubber on the road but can cost more fuel.

The width must match the size the car maker approves for your wheels. A tyre that is too wide can rub on the arch or the suspension. One that is too narrow will not sit properly on the rim. Both tyres on an axle must be the same width. Mixing widths across an axle is an MOT fail. Low profile tyres explains how width and profile work together on bigger wheels.

Not sure what width your car needs? Send the registration to 07943 185471 and we check it for you. Call 0300 124 6981. Tyre sizes lists the widths and sizes we carry most. If the size on the car does not match the door sticker, we will tell you before fitting anything, so you are not left with a tyre that rubs or reads wrong.

The load index is a number that shows the most weight each tyre can carry. 91 means 615kg per tyre. The speed rating is a letter that shows the top speed the tyre is built for. V means 149mph. Together they are called the service description, like 91V.

Always match or beat what the car came with. A higher load index or a higher speed letter is fine. A lower one is not, because the tyre may not cope with the weight or the heat. It can also be an MOT and insurance issue. Heavier cars, vans and electric cars often need a higher load index, sometimes marked XL. Speed and load ratings has the full tables.

Common speed letters: T is 118mph, H is 130mph, V is 149mph, W is 168mph and Y is 186mph. We check the load and speed ratings on every quote, so you never get sent a tyre that is wrong for the car. Call 0300 124 6981 or send the registration. Electric car tyres covers load ratings on EVs, where the weight of the battery makes it matter most.

Your tyre size is moulded on the sidewall of the tyre, in large figures like 205/55 R16. It is also on the sticker inside the driver's door frame, in the handbook under wheels and tyres, and sometimes inside the fuel flap. Or send us the registration and we look it up.

The sidewall shows what is actually on the car. The door sticker and handbook show what the maker approves. They should match. If they do not, a past owner may have changed the size, and it is worth checking before you buy more. It is common on used cars bought with aftermarket wheels. How to check your tyres covers the other things to look at while you are there.

The registration route is quickest. Send it to 07943 185471 on WhatsApp and we reply with the size, the options and a fitted price. Call 0300 124 6981 if you prefer. Tyres by vehicle also shows common sizes by make. If your car has two approved wheel sizes, we check which one is actually fitted, so the tyre on the van is the one that goes on.

XL means extra load. An XL tyre has a stronger build that lets it carry more weight than a standard tyre of the same size, when inflated to the right pressure. You will see it on heavier cars, many SUVs and most electric cars. It is sometimes written as Reinforced or RF.

If your car came on XL tyres, replace them with XL tyres. A standard tyre in the same size has a lower load index, which may not be enough for the car. XL tyres can also need a slightly higher pressure, so check the door sticker. Speed and load ratings shows how the load index changes between standard and XL.

Fitting XL to a car that does not need it is fine. It just means a stiffer tyre with more capacity than you use. We match the load rating on every quote, so you do not need to worry about it. Call 0300 124 6981. Do electric cars need special tyres covers XL and HL on EVs. Both marks are easy to miss, so a photo of the sidewall helps.

ZR in a tyre size, like 225/45 ZR18, marks a tyre built for high speeds, usually W or Y rated. The Z was once the top speed class, and it still appears on many performance tyres. The load index and speed letter after the size give the exact limits.

ZR does not change how the tyre fits. A 225/45 ZR18 and a 225/45 R18 fit the same wheel. What matters is that the speed rating meets what the car needs. On a performance car, that will often be W or Y. Some older tyres show ZR with no letter after, which means over 149mph. Performance tyres covers the high speed end of the range.

If your current tyre says ZR, tell us when you ask for a price, and we will match the speed rating. Send the full sidewall code or a photo to 07943 185471. Call 0300 124 6981. Speed and load ratings lists every speed letter. Performance tyres come in budget, mid range and premium too, so a high speed rating does not always mean a premium price.

The DOT code is a string of letters and numbers on the sidewall that identifies where and when the tyre was made. The last four digits are the date: the first two are the week and the last two the year. So 2323 means week 23 of 2023, and a tyre marked that way is fairly fresh.

The date matters because tyres age even when they are not used. Most makers suggest checking from five years and replacing by ten, whatever the tread. The full date may only appear on one side of the tyre, so if you cannot find it, it may face the inside. When to replace tyres covers when age beats tread.

When we fit new tyres, we check the date so you do not get old stock. If you want the age of your current tyres checked, send a photo of the code to 07943 185471. Call 0300 124 6981. Cracked or perished tyres shows what age looks like on rubber. Tyres made before 2000 used a three digit code, and any tyre that old should come off whatever it looks like.

Only if it is one of the sizes the car maker approves, listed on the door sticker or in the handbook. A different size changes the overall diameter, which can upset the speedometer, the traction control and the ABS, and may rub on the arch. It can also count as a modification for your insurer, so it is not a choice to make lightly.

Some plus sizes keep the overall diameter the same by pairing a bigger wheel with a lower profile tyre. They can work, but they need checking properly. Whatever you fit, the load index and speed rating must still meet the car's needs, and both tyres on an axle must match. Mixing tyres covers the matching rules.

If you are thinking about a size change, ask us first. We will tell you honestly if it makes sense for your car, and tell your insurer if you go ahead. Call 0300 124 6981. Low profile tyres explains the trade off with bigger wheels, and why they often ride harder. Sticking to the approved sizes is almost always the simplest and cheapest choice.

No. Both tyres on the same axle must be the same size and type, but front and rear can differ if the car maker specifies it. Some performance and rear wheel drive cars run wider tyres on the back, called a staggered set up. Most everyday cars use one size all round, which makes buying in pairs simple.

On a staggered car, the front and rear tyres cannot be swapped round, which changes how you plan replacements. You usually buy them in pairs, front or rear, as each pair wears. The rears often wear faster on rear drive cars. Check all four sizes before ordering. Replace two tyres or four helps you plan.

On four wheel drive cars, even with the same size all round, the tread depths should be close, so the drive system does not fight itself. Send the registration and we check the approved sizes for your car. Call 0300 124 6981. Is tyre rotation worth it covers swapping front and rear where sizes allow. We will say plainly whether it is worth doing on your car.

The aspect ratio is the second number in a tyre size, after the slash. It is the height of the sidewall as a percentage of the tyre's width. In 205/55 R16, the sidewall is 55% of 205mm, about 113mm tall. A lower number means a shorter sidewall, a lower profile and a firmer ride over bumps.

Lower profile tyres, like 40 or 35, give sharper steering and fill bigger wheels, but they ride firmer and the rims are more exposed to potholes and kerbs. Higher profiles, like 65, ride softer and protect the wheel better. That is why many vans and family cars use them, and why they cost less to replace. Low profile tyres covers the pros and cons.

You must stick to the aspect ratio the car maker approves for your wheel size. Changing it changes the overall diameter, which the speedometer and safety systems notice. Not sure? Send the registration and we check it. Call 0300 124 6981. Pothole damage shows why low profiles need more care on broken roads, where a sharp edge can bulge a sidewall or crack a rim.

Yes. Send the size from the sidewall or just the registration, and we send back a fitted price and a time. The van carries the common sizes, so most jobs are done in one visit at your home, your work or a safe roadside spot, 24 hours a day.

Rarer sizes we order in and give you an honest time rather than a hopeful one. Each tyre takes about 20 to 40 minutes, balanced on the van, with pressures set to the door plate. There is no call out charge, because fitting is priced into the tyre. You pay by a secure payment link sent to your phone. Tyre sizes lists the sizes we carry most.

We cover 2,700+ areas across the North West and North Wales and are AA and RAC approved. Check where we cover or call 0300 124 6981. Ask, and we can send a photo of the finished job if you are not with the car. Leave the locking wheel nut key out and we can often do the whole job while you are at your desk.