How big are 315 tires


Difference between 35-inch and 315 Tires (Metric vs Standard mm) – 4WheelDriveGuide

When comparing a 35-inch tire to a 315 wide tire, you are basically comparing two completely different measurements. The 35” is a metric value and refers to the width of the tire multiplied by the aspect ratio, which is the height of the sidewall, x2 because there are two sidewalls per tire, divided by the wheel inch, plus the wheel size… Phew!!! That’s a mouthful and a lot to digest at once so let’s break it down into a simple formula.

YES, 315 wide tires are the same as 35” tires although 315 is the tread width in millimeters and 35″ is the tire diameter. 315/70/17 is usually the accepted metric equivalent size for standard/imperial 35-inch tires.

Let’s see what that looks like in a formula form

Tire Size: 315/70R17 (35”)

  • 315 = the metric width of the tire measured in mm
  • 70 = the height percentage (Aspect Ratio) of the sidewall
  • (315 width x . 70 = 220.5mm)
  • Divide mm by 25.4 to get inches
  • So….. 220.50 x 2 sidewalls = 441mm (divided by 25.4 = 17.36″)
  • 17.36″ + 17″ wheel = 34.36″ approximate tire diameter.

Let’s now look into this in a bit more detail

Table of Contents

Metric tire sizes can be a bit more complicated when it comes to understanding what size they really are.

Let’s see what that means.

Metric vs Imperial Millimeters

Understanding the difference between metric and imperial is handy when it comes to tire sizes because you can get really specific. There are so many different tire sizes available today so knowing the difference can mean finding that perfect fit for your truck. A simple way to differentiate is Metric is measured in milliliters and imperial/standard is measured in inches. That’s it!

So when it comes to tire production there’s no official mold that each tire manufacturer uses, however they use their own which basically means there’s no set industry pattern. So the 315/70/17 is usually the accepted metric size for 35” tires, even though the physical diameter of the tire can vary from manufacturer to manufacturer. Two different 35” tire brands can easily vary in true diameter.

This means certain tires are smaller than 35″ like a 34.6” and some will be slightly larger, depending on the brand and overall construction. So, this means a particular 35-inch tire can be somewhat wider in width than another. They are similar in metric size but there are slight differences in construction, weight, pattern, load rating, ply ratings, tread depth, etc.  

One way to find out the exact diameter of a tire is by going to the tire manufacturer’s website and checking the manufacturing specs on that specific tire and then comparing “apples with apples”.

What Size Lift for 35” Tires – Ford F150

The minimum requirements necessary to fit 35x.5 to a Ford F150 are a 4” lift kit and an aftermarket wheel with a more negative offset for improved UCA (Upper Control Arm) clearance. A more affordable option is a 2.5”-3” leveling kit with wheel spacers on the stock wheels combined with fender, body, wheel wells, and bumper plastic trimming

Fitting 35” Tires with no lift – Jeep Wrangler

Fitting 35” tires on a Jeep Wrangler JK with a stock suspension requires the following:

  1. Removal of splash guards
  2. Fit a Rear Spare Wheel Spacer/Extender
  3. Fit Wider Aftermarket Wheel Flairs
  4. Leave the front sway bar connected
  5. Fitting larger bump-stops

So basically, yes it can be done but not without some additional modifications first. If your intention is to go off-road, it is highly recommended to fit a minimum of 2-3” lift to be able to disconnect the front sway bar to take advantage of the Wrangler’s legendary articulation. Don’t forget the larger bump stops or you’ll be picking up fenders on the trail. When flexing, the wheels will scrub heavily against the wheel arches and possibly rip off some plastic if you don’t take it slow.  It won’t be a pleasant experience off-road – believe me!

Fitting 35-inch Tires On Your Truck

Bigger tires are the single most effective method of gaining improved ground clearance. This is especially important for overcoming obstacles in an off-road situation. There are however a few limitations, especially when it comes to IFS (Independent Front Suspension) 4WD vehicles.

Let’s now look at a few factors to consider when fitting 33” tires on your truck.

Lift Kit

Before you even consider fitting 35” tires on your IFS truck, you’ll need to have a minimum 4” lift kit installed. Depending on your truck, sometimes this isn’t enough, since you’ll still need to make additional modifications to prevent scrubbing at full lock. This is especially true if you want to retain full functionality and articulation which is important for off-road. If you decide to go 4” or higher, beware there are serious implications to any IFS suspension, but more on that later.

Who should fit 35” tires? There are mixed opinions when it comes to large tire upgrades, and depending on who you ask, you’ll get differing opinions. I give it a Hell YES! If you can – why not? In fact, I am currently planning a 35” tire upgrade on my truck! The added clearance, aggressive look, and improved traction and stability in my opinion is well worth it. It comes at a price of course.  

Click here for more info on fitting 33” to your truck

Wheel Offset

Wheel offset or backspacing is a factor that gets little consideration, and it can create complications if you’re not sure exactly how much brake caliper clearance is required. The problem here is, you don’t want to go too negative offset on the wheels else you risk too much wheel “poke”.

What is the difference/meaning of backspacing vs Offset?

Backspacing is the distance measured from the hub mounting surface to the inside edge of the wheel. When you decrease backspacing, you gain more inside wheel clearance. There is a fine line between keeping the tires in the guards and preventing scrub on arches, UCA, Brake calipers, etc.

Offset is measured in mm and generally refers to how your wheels sit inside the wheel wells. You get positive and negative offset wheels. When it’s positive the imaginary line is more towards the front and negative means the mounting surface is more towards the rear of the rim creating a deep dish effect.

Fender & Arch Trimming to fit 35’s

Usually, there are a few plastic liners on the inner fender guards that need to be massaged since they will scrub at full articulation. So get comfortable with your Stanley knife and cutter and do some trimming of those wheel arch/guards where they are making contact. You might even have to do some arch rolling, depending on which truck you have and how much space you’re working with.

Be mindful of the inner guard pinch weld and the inside of the fender flare. They usually need some trimming, depending on the tire and vehicle. Fender clearance and backspacing go hand-in-hand with tire width. A wider and taller tire will require more wheel arch clearance and room to move when flexing off-road and when turning at full lock. Don’t forget about your bump stops. Manufactures seldom mention anything about bump stops when selling you suspension components and it’s vital.  

When you squeeze oversized tires into a wheel arch without lifting the truck, you’ll need to trim away a lot of the inside fender and arch plastic to allow the tire to tuck behind the arch when turning and flexing off-road.

Will the 35’s throw out your speedo?

When you upgrade from a stock tire to one with a taller aspect ratio (Sidewall), increasing the wheel circumference, your speedo can be thrown out. In the case of 35” tires, the diameter will be larger and have an increase in the aspect ratio. This might throw out your speedometers reading quite a bit. The increase in tire circumference means the actual speed you are traveling will be higher than your speed reading and get worse the faster you travel.  

The below table will give you an indication of how the speedometer reading is affected from a 32” (275/70R17) to a 35” (315/70R17).

Speedo reading20mph30mph40mph50mph60mph70mph80mph90mph
Actual Speed21.43242.753.464.174.885.596.1

Below are the actual differences between the stock 32” tire and the upgraded 35”

MeasurementStock Tire (275/70/17)Upgrade (315/70/17)Differences
Diameter32.2″34.4″ (874mm)+6.8%
Width10.8″12.4″ (315mm)+14.8%
Sidewall7.6″8.7″ (221mm)+14.5%
Circumference101″107.9″ (2741mm)+6.8%
Revs/Mile627587 (365mm)-25

Conclusion

We have mentioned quite a few variables to consider before dropping a load on expensive oversized tires. You should first determine what the primary application for the upgrade is. Is it purely for aesthetics or will you need maximum practicality, off-road ability, while maintaining maximum articulation?

35×12.5R17 vs 315/70R17 – SIZE/WEIGHT/HEIGHT/LOAD Difference – 4WheelDriveGuide

Understanding tire measurements can be very tricky and complicated, especially when tires are similar in size but described using different measurements. There is the metric measurement and the imperial or standard measurements and these can become confusing very quickly. So what is the main difference between 35×12.5R17 vs 315/70R17 tire?

The 35” tire represents the overall combined width (mm), aspect ratio (%), and wheel diameter (inches) measurement. The 315 tire measurement is a metric value and only represents the tire width which is measured in millimeters.

The two sizes are almost the same but vary somewhat between tire models and brands. Let’s find out what the exact differences are between the two tires when it comes to size, weight, height, and load ratings.

Let’s go!

Table of Contents

35×12.5R17 vs 315/70R17 – SIZE/WEIGHT/HEIGHT/LOAD Differences Explained

So let’s start with the 315/70R17 tire. This tire measurement means the tire is measured as follows:

315 – The tire width, measured in millimeters

70 – The tire aspect ratio (sidewall) height, measured in percentage

17 – The tires wheel circumference, measured in inches

Let’s see what that looks like in a formula form

Tire Size: 315/70R17 (35”)

  • 315 = the metric width of the tire measured in mm
  • 70 = the height percentage (Aspect Ratio) of the sidewall
  • (315 width x .70 = 220.5mm)
  • Divide mm by 25.4 to get inches
  • So….. 220.50 x 2 sidewalls = 441mm (divided by 25.4 = 17.36″)
  • 17.36″ + 17″ wheel = 34.362″ approximate tire diameter.

As you can see above, the 315 70 17 tire measures 12. 4″ wide and 34.362″ tall.

Let’s now see how that differs to a 35/12.5R17

35×12.5R17 vs 315/70R17 – SIZE Differences

So now we know what the 315/70R17 represents, let’s look at how to read and decipher the 35×12.5R17 measurement.

When looking at a 35×12.5R17, the 35” measurement represents the overall tire size which includes the width, aspect ratio, and wheel diameter.  

The 12.5 represents the section width. The Section width is defined as the measurement between the widest point of the outside sidewall to the widest point of the inner sidewall.

17 represents the wheel diameter, measured in inches.

35×12.5R17 vs 315/70R17 – WEIGHT Differences

These two tire sizes might differ slightly in physical dimensions, however, there are factors like load ratings, tire tread pattern, tire molds, etc. that makes the difference. The weight differences can vary between 500g to 1. kg or 1.102 to 2.204 pounds.

315/70-1735/12. 5-17Difference
Diameter inches (mm)34.36 (872.8)35.03 (889.72)0.67 (16.92) 1.9%
Width inches (mm)12.4 (315)12.52 (318)0.12 (3) 1%
Circum. inches (mm)107.95 (2741.98)110.04 (2795.14)2.09 (53.16) 1.9%
Sidewall Height inches (mm)8.68 (220.5)9.01 (228.96)0.33 (8.46) 3.8%
Revolutions per mile (km)586.93 (364.7)575.77 (357.76)-11.16 (-6.94) -1.9%

35×12.5R17 vs 315/70R17 – HEIGHT Differences

As you can see in the above table, the differences in aspect ratio (sidewall height) is roughly 3.8%.

The table below will show how the aspect ratio affects the accuracy of your speedo readings.

Speedometer Difference

Speedo ReadingActual Speed
20 mph (32. 19 km/h)20.39 mph (32.81 km/h)
25 mph (40.23 km/h)25.48 mph (41.01 km/h)
30 mph (48.28 km/h)30.58 mph (49.22 km/h)
35 mph (56.33 km/h)35.68 mph (57.42 km/h)
40 mph (64.37 km/h)40.78 mph (65.62 km/h)
45 mph (72.42 km/h)45.87 mph (73.82 km/h)
50 mph (80.47 km/h)50.97 mph (82.03 km/h)
55 mph (88.51 km/h)56.07 mph (90.23 km/h)
60 mph (96.56 km/h)61.16 mph (98.43 km/h)
65 mph (104.61 km/h)66.26 mph (106.64 km/h)
70 mph (112.65 km/h)71.36 mph (114.84 km/h)
75 mph (120.7 km/h)76.45 mph (123.04 km/h)
80 mph (128.75 km/h)81.55 mph (131.24 km/h)
85 mph (136.79 km/h)86.65 mph (139.45 km/h)
90 mph (144.84 km/h)91.74 mph (147.65 km/h)
95 mph (152. 89 km/h)96.84 mph (155.85 km/h)
100 mph (160.93 km/h)101.94 mph (164.05 km/h)

35×12.5R17 vs 315/70R17 – LOAD Differences

The load range is just a complicated way of telling you what the maximum number of pounds the tire can comfortably support is. It’s a common misconception that Size and load rating are related however they actually have very little to do with each other. 315/70R17s are also available in C/D/E rages.

As you go up in ratings you get improved load carrying abilities and a beefier tire however due to the stiffer sidewall, offering little flexibility you can sacrifice ride quality and added unsprang weight.

Personally, I am a fan of XL for most 4WD ½ ton trucks and SUV applications. Here the application is key i.e. is it your daily driver or is it used as a work truck etc.

SL – Standard load, normal body ply with regular load capacity, P metric like P255/70R17
XL – Extra load, heavier body ply with high load capacity also P metric
C ply(6) rating, heavier body ply with higher load capacity, LT metric like LT285/70R17
E ply(10) rating, heavier body ply with higher load capacity also LT metric

Gas Mileage Difference between 33 and 35” Tires

You can expect 1 to 2 mpg difference when upgrading from 33” to 35“tires. The larger diameter, width, and circumference add to the unsprang weight which has a direct effect on fuel economy, performance, gearing, and other drivetrain components.

Users who have made the switch have reported a decrease of anything between 1-2mpg when cruising on the highway and 2-4mpg when driving in the city. Of course, the truck’s low-down torque and overall performance outputs play a major factor and figures will vary from vehicle to vehicle.

It’s not uncommon for Jeep Wrangler owners to fit 35” tires, since they have SFA and plenty of options to improve wheel clearance. Of course, re-gearing is key. Once you fit 35s it recommended to go with either the 5.13 or 4.88 gears. Even though frugal gas mileage shouldn’t really be your main concern when driving a 4WD, many JK owners report a drop of between

Difference between 35-Inch and 315 Tires (Metric Vs Mm)

YES, 315 wide tires are the same as 35” tires although 315 is the tread width in millimeters and 35″ is the tire diameter. 315/70/17 is usually the accepted metric equivalent size for standard/imperial 35-inch tires.

Click here to get more detail on this topic

Resources

  • https://www.tacomaworld.com/tirecalc?tires=315-70r17-35-12.5r17
  • https://www.wranglerforum.com/threads/315-70-17-vs-35-12-50-17-whats-the-load-differences.2346679/
  • https://www.jeepgladiatorforum.com/forum/threads/35×12-50r17lt-vs-lt315-70r17.16750/

Conclusion

In most cases when comparing physical differences most 35″ tires hardly crack the 34″ mark in actual tire size. If you find a tire that has both “315” and “35” measurements take a look at load range/speed rating to determine the best fit for your application.

315/70 R22.5 vs 295/75 R22.5 Tire size comparison with graphical visualization

Your machine size

/ 2530354045505560657075808500 R 121314151617181920212222. 52324

Calculate

135145155165175185195205215225235245255265275285295305315325335345355365375385395 / 2530354045505560657075808500 R 121314151617181920212222.52324

New tire size

CM INCHES


Index Old New Difference
Diameter - - -
Width - - -
Circumference - - -
Profile height - - -
RPM - - -
Clearance change -
Result: -

With speedometer:

Real speed will be:

Comparison of tire sizes 315/70 R22.

5 and 295/75 R22.5.

In the table above you can see a detailed comparison of the difference in dimensions, parameters and performance between a tire with size 315/70 R22.5 and a tire with size 295/75 R22.5. The results of the calculations are also presented in the form of visual models (infographics), on which the tire with a size of 315/70 R22.5 is on top, and with a size of 295/75 R22.5, respectively, at the bottom. The visualization was generated in two projections: lateral (left) and frontal (right). The online calculator compares tires according to the following characteristics: diameter, width, circumference, profile height, revolutions per km, ground clearance change. Additionally, the potential deviation between the actual speed and the speed displayed on the speedometer is calculated, which may occur if the difference between tires 315/70 R22.5 and 295/75 R22.5 is significant.

If you want to compare other tires, just select the required parameters in the drop-down fields and click on the green button.

Infographic

Side Comparison Frontal comparison

See also:

Vehicles - rules, regulations, regulations

Tire sizes.

Tire sizes are represented by outer diameter, section width and static radius for each truck and passenger car tire designation.

1. Tire dimensions in accordance with GOST R 52899-2007 “Pneumatic tires for cargo motor vehicles and trailers. Specifications".

Table 1. Light truck tires.

Tire designation Main dimensions, mm Static radius ±1.0% (reference)
OD ±1.0% Profile width, not more than
185/80R15C 674 188 310
215/80R16C 755 218 355
225/75R16C 744 228 338
5. 90-13C 620 154 292
6.40-13C 645 172 303
215/90-15C 777 218 364
6.50-16C 760 180 360
175/80-16C 692 178 326

Light truck tire designation 185/80R15C:

185 - designation of the nominal section width of the tire in millimeters;

80 — nominal ratio of tire profile height to its width, %;

15 - designation of the nominal fitting diameter of the rim in inches;

C is a symbol that identifies a light truck tyre.

R - radial tire.

Table 2. Tires for trucks.

Tire designation Rim designation Main dimensions, mm Static radius ±1.5% (reference)
recommended
blown
tolerable OD ±1. 5% Profile width, not more than
Diagonal
7.50-20 6.0-20 6.5-20 928 213 443
8.25-20 6.5-20 6.0-20 970 234 462
9.00-20 7.0-20 6.5-20 1012 256 481
10.00-20 7.5-20 8.0-20 1050 275 498
11.00-20 8.0-20 8.5-20 1080 291 511
12.00-20 8.5-20 9.0-20 1120 312 529
12.00-24 8.5-24 9.0-24 1220 312 576
Radial chamber
7. 50R20 6.0-20 6.5-20 928 210 440
8.25R20 6.5-20 6.0-20 962 230 453
9.00R20 7.0-20 6.5-20 1018 258 475
10.00R20 7.5-20 7.0-20

8.0-20

1052 275 491
11.00R20 8.0-20 8.5-20 1082 286 505
12.00R20 8.5-20 9.0-20 1122 313 526
12/80R20 8.5-20 9.0-20 1008 305 472
12.00R24 8.5-24 9.0-24 1226 313 570
8.25R15 6.6-15 7. 0-15 836 234 385
Radial Tubeless
10R22.5 7.50×22.5 6.75×22.5 1020 254 476
11R22.5 8.25×22.5 7.50×22.5 1050 279 489
12R22.5 9.00×22.5 8.25×22.5 1084 300 504
385/65R22.5 11.75×22.5 12.25×22.5 1072 389 505
275/80R22.5 8.25×22.5 7.50×22.5 1012 276 470
295/80R22.5 9.00×22.5 8.25×22.5 1044 298 490
315/80R22.5 9.00×22.5 9.75×22.5 1076 312 499
350/80R22. 5 11.75×22.5 12.25×22.5 1122 355 526
11/70R22.5 8.25×22.5 7.50×22.5 962 279 447
315/70R22.5 9.00×22.5 8.25×22.5 1014 312 467
425/65R22.5 13.00×22.5 14.00×22.5 1122 425 525

Tire designation example: 8.25R20 is the designation of the tire, where 8.25 is the designation of the nominal section width of the tire in inches, R is the letter index of the radial tire, 20 is the designation of the nominal rim diameter in inches.

Tire section width measured on the recommended rim. When mounted on a permitted rim, the profile width changes by 40% of the difference between the widths of the recommended and permitted rims.

2. Tire sizes for passenger cars according to GOST 4754-97 are presented in Table 3.

Table 3.

Tire designation Road tire dimensions, mm, on recommended rim
O.D., (limit devi.
±1%)
Profile width, not more than Static radius (off limit
±1%)
Rolling radius (reference)
135/80R12 521 140 239 252
155/80R13 578 157 263 279
165/80R13 596 167 271 287
175/80R13 608 172 276 293
165/80R14 622 172 284 301
175/80R16 686 178 315 330
155/70R13 548 157 252 267
165/70R13 568 167 260 275
175/70R13 580 176 265 281
185/70R13 598 188 272 287
175/70R14 600 176 278 293
185/70R14 624 187 285 301
205/70R14 652 206 295 313
185/65R13 568 191 260 275
165-13/6. 45-13 610 167 285 291
175-13/6.95-13 610 178 282 288

An example of tire designation 165/80 R13: 165 - designation of the nominal width of the tire profile in millimeters, 80 - series (nominal ratio of the height of the profile to its width in percent), R - letter index of the radial tire, 13 - designation of the tire diameter , corresponding to the nominal diameter of the rim in inches;

3. Tire sizes according to GOST 13298-90 “Tyres with adjustable pressure. Specifications".

Table 4.

Ply rate Rim designation Tire dimensions, mm
12.00-18 8 465-228
(228G-457)
1084±8 337 505±5
13.00-18 8 465-228
(228G-457)
1132±8 351 525±5
12. 00-20 8 514-228
(228G-508)
1142±8 335 530±5
14.00-20 10 515-254
(254G-508)
1260±10 390 583±5
16.00-20 10 515-292
(292-508)
1384±10 460 632±5
1200 x 500-508 10 514-400
(400G-508)
1177±15 481 540±7
1220 x 400-533 10 533-310
(310-533)
1200±15 418 560±7
1300 x 530-533 12 533-440
(440-533)
1280±15 525 585±7
1500 x 600-635 10
14
500-635 1500±15 610 680±10
1600 x 600-685 24 500-685 1590±15 600 725±10

Example 1.


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