When shopping for a new set of tires, choosing the right tire size is of paramount importance. Although there might be several tire options that fit your wheels, they’d differ in terms of ride comfort and performance.
If your car has a wheel diameter of 16 inches, 285 70r16 and 285 75r16 are two tires that you’re probably considering. Both these tires are great options for such smaller wheels and happen to be popular choices.
285 70r16 vs 285 75r16: Differences
The two tires in question are very similar to each other, with only a slight difference in their dimensions. This is why it’s a tad hard to choose between the two, but we’ll be evaluating the differences in detail soon. First, let’s check out how you can obtain the specs of a tire to compare it against a different tire size.
In case you didn’t know, the index number of a tire consists of different specifications of the tire, with each part of the number denoting a parameter. Just from reading a tire index number, you can get information on four different parameters in the following order:
- Overall width (in millimeters)
- Aspect ratio (in percentage)
- Construction type
- Rim diameter (in inches)
Does the index number seem too complicated to decode for the specs? Don’t worry, you’ll soon get a practical demonstration as we compare 285 70r16 and 285 75r16 based on these parameters.
Width
To get the width of a tire, you just need to read the first segment of its index number. These three digits denote the tire’s width in millimeters. In this case, both tires share the same width – 285mm.
The width of a tire directly impacts the traction it offers, as a larger surface area touching the road results in greater traction. As 285 70r16 and 285 75r16 are equally wide, you won’t find any difference in this regard.
The width of these two tires is one of the reasons why they are great choices for your car.
Putting on such wide tires on your car will help you gain more traction and get a better grip on the road while accelerating. However, you should bear in mind that steering the car might feel a little heavy if you’re using wide tires.
Aspect ratio
As we can see from the index numbers, this is the only parameter among the four where the two wheels differ. Not sure what this aspect ratio means? It’s simply the ratio between the height of the sidewall and the tire’s overall width. The two digits in the second part of the index number stand for the tire’s aspect ratio.
Between 285 70r16 and 285 75r16, the latter has a higher aspect ratio of 75%, while the former comes with a 70% aspect ratio. Keeping in mind that the two tires are equally wide, a higher aspect ratio can mean only one thing – 285 75r16 has a taller sidewall.
The taller the sidewall height, the more comfortable the ride would be. This is simply because the additional sidewall height adds to the tire’s suspension, allowing it to absorb shocks while driving.
While both tires boast impressive aspect ratio and sidewall height, 285 75r16 is the clear winner. However, 285 70r16 offers an advantage too – a lower sidewall height delivers more lateral stability while driving.
Construction type
The letter that follows the aspect ratio represents the tire’s construction type. While this isn’t a part of a tire’s dimensions, it has a major impact on ride comfort and the durability of a tire.
Primarily, tire manufacturers use either radial or cross-ply construction.
The former is more sophisticated and far more popular due to its distinct advantages. As for the two tires that we’re comparing, both feature radial construction (as represented by the letter r).
Tires built using the radial construction method are more flexible as they don’t have an inner tubing, which also makes them better at absorbing shocks.
A radial tire will therefore ensure a more comfortable ride than a cross-ply tire. While cross-ply tires are sturdier and more durable, radial tires make up for it with greater heat and water resistance.
Rim diameter
The rim diameter of a tire is the last parameter covered in the index number, represented by the two digits at the end. Do note that unlike the width of the tire, the rim diameter is presented in inches.
Both 285 70r16 and 285 75r16 come with a 16-inch rim diameter. The tires have the same rim diameter, so they both fit the same cars. If 285 70r16 fits your vehicle, so will 285 75r16.
Thus, we can see that the two tires are the same in all four parameters represented in the index numbers except for the aspect ratio. Below is a table comparing the specs side-by-side, along with some additional parameters.
| Parameters | 285 70r16 | 285 75r16 | Differences |
| Width | 285 mm | 285 mm | 0 |
| Sidewall height | 199.5 mm | 213.75 mm | 14.25 (7%) |
| Aspect ratio | 70% | 75% | 5% |
| Rim diameter | 16 inches | 16 inches | 0 |
| Circumference | 2530.24 mm | 2619.77 mm | 89.54 mm (3.5%) |
| Overall Diameter | 805.4 mm | 833.9 mm | 28.5 mm (3.5%) |
Going through the table above, we can see that 285 75r16 is a larger tire with 3.5% greater overall diameter and circumference. This, of course, is normal considering this tire has a taller sidewall than 285 70r16 while featuring the same rim diameter.
Conclusion: Which one to choose and when?
Both 285 70r16 and 285 75r16 are good options for your car and offer ample traction due to their width. The difference lies in their aspect ratio and the resulting performance – 285 70r16 offers more lateral stability while you’ll enjoy a more comfortable ride on a set of 285 75r16 tires.
Overall, 285 75r16 is a better choice, especially if you tend to drive on rough roads and would like some extra suspension. However, if you prefer to get maximum stability from your tires, go for a set of 285 70r16 tires.
