Choosing the wheel width is as important, if not more important than choosing the right diameter. In this article, I’ll compare 8″, 8.5″ and 9″ wide alloy wheels so you can decide which is the best choice for your car.
The Quick Answer
When comparing 8″, 8.5″ and 9.0″ alloy wheels on the same size tire, the wider alloy is more likely to get curbed and the ride will be harsher. If the tire size was also increased, the wider wheel would offer more grip in dry conditions but would be more likely to aquaplane and be less fuel efficient.
Before we jump into the comparisons, we need to first address the tire compatibility for each wheel width, because the size of the tire will have a big impact on the performance and comfort levels of the car.
Here is a table to show the average compatible tire sizes for each alloy wheel width. You should always check with the manufacturer before fitting the tires to ensure they are the appropriate size as the limits are not the same for every tire.
|Alloy Wheel Width||Ideal Tire Width||Minimum Tire Width||Maximum Tire Width|
|8.0”||225 mm or 235 mm||215 mm||245 mm|
|8.5”||235 mm or 245 mm||225 mm||255 mm|
|9.0”||245 mm or 255 mm||235 mm||265 mm|
In the rest of the article, we’ll discuss that changing the wheel width will have on the car. This varies depending on whether you’re also changing the tire size as well, so the article has been split into two main sections:
- Differences when using the same width tire
- Differences when changing the tire width
Differences When Using the Same Tire
The reason that you may want to go with the same tire size for a slightly wider rim is so that the wheels still fit the wheel arch and do not protrude outwards.
You should not deviate from the recommended tire sizes as given by supplier. For example, if you have 225 mm tires on an 8.0″ wheel, these will not be compatible if you change to a 9.0″ wheel and would be too “stretched”. Make sure you check with the supplier and fitter before making changes to make sure that the wheels are a suitable size.
As long as the tire size is still compatible for the alloy size, you won’t run into any issues by using the same tire size when increasing or decreasing the width of the wheel. For example, if you currently run 245 mm wide tires on 8.5″ rims, then using the same size tire on a 9.0″ rim should not cause issues with most tires.
However, it will change a couple of things about the car.
Firstly, the width of the tire in comparison to the alloy affects the way the wheel looks. A wider rim on the same size tire will mean the tire is more flush with the edge of the wheel compared to if the rim was narrower where it would extend past the edge more.
Not only does this change the appearance, but it also affects how likely the alloys are to get damaged. The wider the alloy is (and hence more flush the tire will be to the edge), the more likely it is to get curbed. Choosing a smaller width alloy means the tire will provide more protection.
It will also make the ride feel a bit harder and have a negative impact on handling. Using the same width tires for a wider rim will have no performance benefits and will actually be detrimental instead. The main reason it is done is for aesthetics or to ensure the wheel still fits in the arch.
Differences When Changing the Tire Size
In many cases, when you want wider alloys, you’ll also want to increase the width of the tire to ensure it’s a good fit. When this is the case, the impact on performance and handling is really related to the width of the tire instead, and the width of the alloy won’t make much of a difference except for adding more weight which can reduce acceleration.
Let’s take an example to illustrate the changes this will have using the following three wheel sizes:
- 8.0″ wide wheel with a 225 mm tire
- 8.5″ wheel with a 235 mm tire
- 9.0″ wheel with a 245 mm tire
In this case, the 8.0″ wheel and 225 mm tire would be the least prone to aquaplaning, have better fuel economy, less road noise and be cheaper. On the other hand, the 9.0″ wheel and 245 mm tire would offer more grip in dry conditions and faster acceleration and braking. The 8.5″ wheel and 235 mm tire would of course sit between the two.
|Narrow Tires and Alloys||Wide Tires and Alloys|
|Less prone to aquaplaning||Better grip in dry conditions|
|Faster when at constant speed||Faster acceleration and braking|
|Better fuel economy||Worse fuel economy|
|Less road noise||More road noise|
It’s also worth noting that the performance benefits of the wide tire (acceleration and dry grip) only really come into play when the car is powerful enough. If the car doesn’t have a lot of power, then choosing a very wide tire is unlikely to add much benefit.
The final point that’s worth mentioning, is the difference between 8, 8.5 and 9 wheels in terms of the overall price. If you are choosing wider tires as well as wider wheels, this will increase the price. However, in most cases, there is no difference between the price of the alloys wheels according to the width. It’s usually just the diameter which makes a difference.
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