How Big is a 315 Tire? Size and Performance Insights?

Technical Discussions
1

I’ve been researching tire sizes for a while now, and I keep coming back to the 315 tire, particularly the 315/70R17 variant. I’m trying to get a better understanding of how big this tire actually is, both in terms of dimensions and how it compares to other tire sizes.

Here’s what I’d like to know:

  • Dimensions: What are the specific measurements of a 315 tire? I’m curious about both width and sidewall height and how these translate onto a vehicle.
  • Vehicle Compatibility: Can anyone share insights on which types of vehicles this tire size is typically used on? I want to know if it will fit my SUV or if I need to look for something else.
  • Performance Impact: How does a 315 tire affect handling and overall performance? I’m interested in how the size might change the driving experience, particularly on off-road terrains.
  • Comparisons: How does the 315 tire stack up against other sizes like 275 or 295? If anyone has experience with these comparisons, I would appreciate the input.

Any guidance or personal experiences would be really helpful! I’m looking to make informed decisions that affect my vehicle’s performance and safety. Thanks in advance for your help!

2

A ‘315 tire’ typically refers to the width in millimeters. So, it’s 315 mm wide, but we need to consider the aspect ratio and diameter too for a complete picture of its size.

3

Exactly! And the aspect ratio tells us the height of the sidewall as a percentage of the width. So, if it’s a 315/60, the sidewall height is 60% of 315 mm.

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4

Additionally, the diameter is another key factor. Typically, the last two digits in the tire size (e.g., 20 in 315/60R20) tell us the diameter in inches. This influences handling and ride comfort.

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5

The diameter can drastically affect performance, especially in how quickly a car accelerates. A bigger tire means heavier rolling resistance.

6

A 315 tire can provide great traction, especially on larger vehicles, but you need the right width for your rims too. What kind of vehicle are you using that requires a 315?

7

That’s a good point, @michaelgallagher! Proper fitment is crucial. Too wide, and you risk poor handling; too narrow, and it can affect grip.

8

I once read that changing to 315 tires on a vehicle can also alter its speedometer reading. Has anyone experienced this?

9

Yes, that’s true! When you increase tire size, the overall circumference changes, which affects speed readings and gearing.

10

While larger tires can enhance grip and aesthetics, they might also impact fuel economy. It’s a balance to find what works best for your driving style.

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11

Definitely! But the performance can vary based on tire brands too. Anyone have personal favorites for 315s?

12

I have some Nitto NT05s in 315, and they grip like crazy! Perfect for track days while also being street-friendly. Plus, they look aggressive!

13

One little downside, though: they can wear out faster with aggressive driving. Gotta keep an eye on those tread depths!

14

Very true! Tire maintenance is important. Keeping track of air pressure can help extend their lifespan!

15

A 315 tire generally has a width of 315 mm and is a popular choice for larger vehicles. For it to fit properly, you need to consider your vehicle’s wheel well clearance and suspension height. Always consult your owner’s manual and check dimensions!

16

Great advice! It really helps to know the width. I’ve also read that the wheel width should be between 10 and 12 inches for a proper fit.

17

Most importantly, check your current tire size. If you’re going from something narrower, be aware that you may need to lift your suspension or make body modifications, especially if you’re off-roading.

18

That’s true! I have a friend with a JK, and he needed spacers alongside a lift to make it work without rubbing.

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19

Exactly! I’ve seen people fit 315 tires on trucks after adding a leveling kit. It allows for that extra clearance and avoids rubbing issues.

20

If you’re considering 315s for a Jeep, be prepared for potential fender trimming, especially if you’re on stock suspension. It can be a tight fit without modifications.