Wheels and Tyres – What is the difference?

We need to do something before discussing the pros and cons of fitting new tyres and/or wheels to your vehicle. Believe it or not, but there are people who use wheels and tyres as referring to the same thing. They are not. Let me explain. A wheel is a round object with a hub and an axle. A tyre is the rubber part that is set around a wheel and that grips the road. Think about it, not all wheels have tyres. Remember the old iron wheel wheelbarrow? Those wheels had no tyres, and what about a wagon wheel? They would also not have a tyre, but that wagon would still have its four wheels!

Let us get more focused on the wheel itself, because even that may be broken up into parts. A wheel is comprised of a wheel disk and a rim, as pictured below.

You can, therefore, see that the rim is the outer part of the wheel that holds the tyre. The rim is not the wheel! It is technically incorrect to refer to the wheel as a rim.

Upgrading the wheels and tyres

Is your car an extension of your personality? Many people feel that it is, and there is absolutely nothing wrong with fostering this feeling. As such, you want your car to be as unique as you are. Those standard old wheels and tyres with which it left the factory, just won’t do it for you. Changing the wheels and tyres is also one of the first things owners do to personalise their cars. This is because changing the wheels and tyres is a relatively simple thing to change. By doing that, you know your car will stand out from the crowd. However, changing the wheels and tyres from what the manufacturer intended can have negative consequences.

The Disadvantages

The most relevant to everyday motorists is the fitment of larger tyres on your existing rims. Some people might feel that wider tyres are better and safer than the “Marie biscuits” fitted by the manufacturer. In some cases, this may be true, but there are disadvantages. Wider tyres might offer more grip in dry weather, but will also be more susceptible to aquaplaning. Aquaplaning? Yes, you may not know it by its name, but most probably by its experience. It refers to that terrifying moment when you hit a big puddle of water and lose all control. This happens because the wide tyres cannot “bite” through the water to maintain contact with the road. They also cause more rolling resistance, which can be partly solved by higher pressures – worsening ride quality.

Tyres with a higher profile will increase your gearing. As a result, you will travel a little faster for the same engine speed and lose some torque and acceleration. This is due to the bigger circumference of the tyres and their bigger weight that requires extra acceleration. On the positive side, the slightly lower engine speeds might be favourable for your fuel consumption. Your ride might be a bit softer on the plumper tyres and your speedometer error might be less. In the case of both wider and higher-profile tyres, you should keep the changes modest. This is necessary to maintain the balance of your car’s handling. It will also ensure that the larger rubber ware does not snag the wheel arches.

Fuel consumption and the odometer reading

Usually, the manufacturers know best for your specific car. It will drive and perform well on its standard wheels and tyres. It might not be worth it to pursue a 2% improvement in fuel consumption by fitting high-profile tyres. This is especially noteworthy when the disadvantages might nullify that improvement under certain circumstances. Remember, even though larger-circumference tyres might make your speedometer more accurate, it will affect your odometer. With a pessimistic odometer, your fuel consumption will appear to be worse than it really is. Compare your odometer reading with that of the kilometre beacons next to the national road over a considerable distance.

Do you want to read more about wheels? Have a peek at “the complete guide to wheels”, by clicking here.

Your engine does not offer optimal power or economy in the state it leaves the factory. Because of mass production, many constraints are placed on the engine. It may be a surprise to you, but with the Unichip, there is almost always room for vehicle improvement. Fit a Unichip and realise your engine’s full potential. This way, you are more likely to achieve worthwhile improvements than the doubtful advantages different tyres might bring. Become part of the Unichip family and buy your Unichip today. Click here to contact us.