# What does zr18 mean on a tire?

Posted On 16 Mar 2022. The letters ZR on the sidewall relate to a tyre’s speed rating, which in this case is 150mph. That means it should not be driven at speeds in excess of 150mph (240kmph) – of course, where such speeds are even legal!

## What does 225 40zr18 mean?

225/40R18 92Y. The first three digits on the sidewall of your tyre show the width in millimetres. For example, this means that if the tyres first three digital have been marked ‘225’, the tyre will then measure exactly 225mm across its tread from one sidewall to the other.

## What’s the difference between r20 and zr20 tires?

ZR basically means the tyre is adapted for speeds above 149 mph. ZR tyres includes the speed ratings V(149mph), W(168mph) and Y(186mph).

## Is ZR tire better than R?

R indicates that the structure is RADIAL. So, VR indicates that the tyre has a RADIAL structure and a speed index equal to V. There is therefore no difference between a ZR or an R tyre with the same speed index.

What does zr18 mean on a tire? – Related Questions

## What does the Z mean in tire size?

SPEED RATING Z

While it nearly always means a high performance tire for high-performing sports cars, “Z” may actually appear in the middle of a tire’s size information. When it does, it represents either a maximum speed of more than 149 mph (240 kph) or 186 mph (300 kph).

## What does the R and Z mean on tires?

ZR: This isn’t necessarily relevant to the tire’s size but rather the construction, with the “R” meaning that it’s a radial tire (the Z refers to speed rating, most tires will have construction only here—only Z-rated tires have the speed rating here)

## What is better R or D on a tire?

A radial tire flexes more than a bias tire, giving it better ground contact, traction, stability, and tread wear. A radial tire will normally run cooler than a bias ply tire, especially when the tire is under a load. A tire that runs cooler will last longer. For those reasons I would recommend an R tire over a D tire.

## What does R and Y mean on Tyres?

V, Z, W, Y and (Y) are for sports cars. L rated tyres are primarily for off-road and light trucks. Q is primarily for winter 4x4s. R is primarily for heavy-duty light trucks.

## What is the difference between R and D in tire size?

The D indicates that the tire is a diagonal bias ply construction and the R indicates that the tire is a radial tire… view full answer

## Can you mix D and R tires?

Expert Reply: It’s fine to use a radial-type tire as a spare (a tire with “r” in its size code) with a trailer that has Bias ply “d” tires but for a short distance in the event of a flat tire. But mixing tires is not recommended for everyday use because their internal construction is different.

## Does the R matter in tire size?

The speed rating is the letter that follows the load rating, but you may also see it following the “R” on some tires. This indicates the maximum speed the manufacturer designed the tire to handle.

## What’s better bias ply or radial?

Radial tires dissipate heat better than bias-ply tires, which allows them to travel at higher speeds for greater distance. “Due to a rigid tread, single steel body ply construction and the absence of multiple nylon plies, radials are much more effective at reducing heat,” says Mills.

Poor transport handling, since low lateral stiffness causes the tire sway to increase as the speed of the vehicle increases. Increased vulnerability to abuse when overloaded or under-inflated. The sidewall tends to bulge which could cause damage and puncture.

## What is a major disadvantage of a bias ply tire?

Radials are often more prone to sidewall failures. This is a key reason bias tires are often the default choice for agricultural, industrial, and slow-speed off-road applications. Another major disadvantage of bias ply tires is their poor sidewalls.

## Why do trailers still use bias ply tires?

Bias ply tires have stiff sidewalls, so they are advantageous for carrying heavy loads. Stiffer sidewalls also help reduce trailer sway.

## Why are truck tires not allowed on trailers?

The dangers. When a car or truck tire is used on a trailer, it causes stress that the tire wasn’t designed to handle. The tread of the tire begins wearing differently than it was designed. The tire’s actual weight capacity is different from the load rating shown because of the different frame designs.

## Why can’t you put trailer tires on a truck?

If they are the same size, yes you may. However if the tires are specifically designed for trailer position, they will not last long on the drive axle of the truck. They will wear out very quickly.

## Why do you not balance trailer tires?

One reason people do not balance trailer tires is that the balance weights have a tendency to bounce off when the trailer is unloaded and being towed. The light load of the trailer can sometimes cause the trailer to bounce as it travels down the road which causes the weights to come off.

## Why do trailer tires wear out so fast?

That said, rapid or significantly uneven trailer tire wear can be caused by: Riding with the wrong tire pressure. Exceeding your tires’ load capacity. Trailer misalignment or bent wheels from hitting curbs, potholes or debris.