What is the difference between 16 inch wheels and 18 inch wheels and tires? In terms of speed increase, what are the operational differences in steering?

Don't look at the diameter of the aluminum alloy wheel, but look at the diameter of the aluminum alloy wheel with the tire. Generally speaking, the same car with different configurations produced by the manufacturer sometimes uses a smaller wheel hub, but the aspect ratio of the tire will also increase, and the final difference is not large.

The same applies to individual high-end models with large aluminum alloy wheels. Large aluminum alloy wheels will increase ground clearance and comfort will be improved. There is generally no difference in operation. If you replace a tire with a different size from the original factory, the power and fuel consumption will change, and the speedometer will be accurate. But the difference is not too big, most people can adapt, if you are a novice may not feel it.
First give an example such as 235 70 16 First of all, what does 235 70 16 mean. 235 refers to the cross-sectional width of the tire (note that it is not the actual contact area between the tire and the ground. The dealer¡¯s propaganda has already affected the encyclopedia, because the tire The difference in shape leads to incomplete shoulder contact with the ground, so it refers to the cross-sectional width of the tire) 70 refers to the flatness of the tire (for example, 70% of 235 is 16.45cm) 16 refers to inches (one inch is 2.54cm) , 16 inches is 40.64) So the tire diameter of 235 70 16 is 16.45 (upper height) + 16.45 (lower height) + 40.64 = 73.54cm and then change to another size, such as 235 65 18 and so on. The tire diameter of 235 65 18 is 45.72 (18 inch +5.27523.5cm¡Á0.65) + 15.275 (thickness above and below the rim) = 76.27cm, which means that the tires of 235 70 16 are smaller than the tires of 235 65 18. This smallness does not mean the contact area with the ground. It refers to the diameter. The diameter of the tire directly affects the speed judgment of the driving computer. If it is changed blindly, it will cause inadvertent speeding (the diameter of the computer judges the number of laps earned by the tire becomes larger, and the distance of the same lap becomes longer) , But also increase the load of the engine, the gain is not worth the loss.
The higher the aspect ratio, the thicker the tires, and the better the adaptability to complex roads. This is why off-road vehicles have high aspect ratios. Of course, the high aspect ratio causes the tire to be very thick. Although the passability and adaptability are enhanced, the handling and high-speed stability will be reduced. Because the distance between the rim and the ground is very long (the tire sidewall is thick), the handling is reduced.

When the aspect ratio is very low, the aluminum alloy wheels are almost in direct contact with the ground, resulting in a heavy load on the tires, increased damage rate, decreased comfort, and increased shock absorption and engine load. But the controllability will be improved accordingly, and the stability will also be improved.
Therefore, the tire model of each car is the data obtained by the manufacturer through rigorous calculations. As far as you are concerned, you should not change the tire casually. You need to consider the following factors when refitting:
1. Local traffic regulations (will not affect the annual inspection of vehicles, vehicle warranty, etc.);
2. Tire speed and load index;
3. The specifications of the wheel hub, such as: width and offset, etc.;
4. Space;
5. The suspension system of the car;
6. (Important) The load radius of the tire remains unchanged;
In general, the difference and particularity of tire size is not to look at the diameter of the wheel, but to look at the diameter of the wheel with the tire.
Generally speaking, the same car with different configurations produced by the manufacturer sometimes uses a smaller wheel hub, but the aspect ratio of the tire will increase, and the final difference is not big. The same applies to individual high-end models with large wheels. Large wheels will increase the ground clearance, comfort will also be improved, there is generally no difference in operation. If you replace a tire with a different size from the original factory, the power and fuel consumption will change, and the speedometer will be inaccurate, but the difference will not be too great. Most people can adapt to it. If you are a novice, you may not feel it.