Gear Ratio and choose gear ratio

What is Gear Ratio and choose gear ratio?

What Gear Ratio Do I Need, this is a burning question if one is driving a car and altering some features like tier size regularly. Many do not know the importance of putting the car into the right gear while driving it. Concerning simple but crucial things like this one will save the engine and keep it healthy for a longer time. Also, one can have proper speed and driving experience with the right gear ratio.

Deciding the exact gear ratio will depend on some mathematical calculation if one has made some changes. For that, they will have to read through the article properly.

What Gear Ratio Do I Need?

In automotive nothing is harder and either is easier. Sometimes a simple question needs a complicated explanation. Also, the simplest-looking feature of the car needs a proper explanation with terms, theory, and mathematics to understand. When one is driving a car they need too many things in their head to drive safely and properly. That is why they need to know the correct gear ratio for their driving style and their car.

One may ask why it is important to know the gear ratio of a car. Well, putting the car into the right gear ratio will affect the overall performance of the car as well as the fuel economy of the car. Besides, if one put the car in the wrong gear ratio they will hear a clanking noise as if something is breaking inside the car. it will create extreme traction between the teethes of the metal gear. In simple words, one should put the gear between 25% and 50% of the gear.

If one put the wrong gear ratio in the car, that means the engine will have to work out of its optimal RPM. If one does not know, the gear ratio of any car will depend on the tier size and the rpm of the engine. Driving the car into too low or too high a gear ratio, the engine will get erosion as well as the axels of the car.

Sometimes people change the diameter of their tier and then put the car into the same gear ratio. That makes a huge crisis in the performance of the car mainly when the transmission is manual. Because an inch difference in the tier will alter the calculation of the gear ratio. We have already mentioned that if it is too high and too low, the engine will get affected in a harmful way.

Besides, the gear ratio of any car will determine the speed of the car. Different gear ratios will allow the drivers to have a different range of speed. Powering up the vehicle at such a speed that the gear cannot handle will cause serious damage to the metallic part of the system.

Luckily there are many ways to calculate and find out which gear ratio one will need. The hardest way to calculate it is based on the gear teeth of the car. The law to find out gear ratio based on the gear teeth is,

“Gear Ratio = (Input Gear Teeth Number / Output Gear Teeth Number)”

We mentioned that this calculation is hard because it is not normal for every car owner to know the gear teeth number. Maybe it will be easier for a mechanical person but not for the majority of people. That is why everyone prefers the easiest way to calculate which involved the tier size and RPM of the engine.

“Gear ratio= (RPM x Tire Diameter Inches) / (Final Drive Ratio x Transmission Gear Ratio x 336)”

In case one does not know the final drive ratio and transmission gear ratio, they can calculate it in a different way. The formula is,

Gear Ratio = (RPM X Tire Diameter) / (MPH X 336)

For example,

Let us imagine that we have a car that has a 3000 RPM engine with 21 inches tier. So, the gear ratio for 60 MPH speed will be

Gear Ratio = (3000 X 21) / (60 X 336)

=3.13

Let’s have a look at the table below illustrating some of the common gear ratios based on tier size and RPM.

Gear ratio
Tier size
3.31
3.42
3.55
3.73
3.91
4.11
4.27
4.56
4.88
5.13
5.29
5.38
5.71
6.17
7.17
27"

2677

2766

2872

3017

3163

3325

3454

3689

3947

4150

4279

4352

4619

4991

5800

28"

2582

2668

2769

2909

3050

3206

3331

3557

3806

4001

4126

4196

4454

4813

5593

29"

2493

2576

2674

2809

2945

3095

3216

3434

3675

3863

3984

4052

4300

4647

5400

30"

2410

2490

2584

2715

2846

2992

3109

3320

3553

3735

3851

3917

4157

4492

5220

31"

2332

2409

2501

2628

2755

2896

3008

3213

3838

3614

3727

3790

4023

4347

5051

32"

2259

2334

2423

2546

2696

2805

2914

3112

3331

3501

3610

3672

3897

4211

4894

33"

2191

2263

2349

2469

2588

2720

2826

3018

3230

3395

3501

3561

3779

4093

4745

34"

2126

2197

2280

2396

2512

2640

2743

2929

3135

3295

3398

3456

3668

3963

4606

35"

2065

2134

2215

2328

2440

2565

2664

2845

3045

3201

3301

3357

3563

3850

4474

36"

2008

2075

2154

2263

2372

2493

2590

2766

2961

3112

3209

3264

3464

3743

4350

37"

1954

2019

2095

2203

2308

2426

2520

2692

2881

3028

3123

3176

3370

3642

4243

38"

1902

1966

2040

2144

2247

2362

2454

2621

2805

2948

3040

3092

3282

3546

4121

39"

1854

1915

1988

2089

2190

2302

2391

2554

2733

2873

2962

3013

3198

3455

4015

40"

1807

1867

1938

2037

2135

2244

2331

2490

2664

2801

2888

2937

3118

3369

3915

41"

1763

1822

1891

1987

2083

2189

2275

2429

2599

2733

2818

2866

3042

3287

3819

42"

1721

1778

1846

1940

2033

2137

2220

2371

2538

2668

2751

2798

2969

3208

3728

43"

1681

1737

1803

1894

1986

2087

2169

2316

2479

2606

2687

2733

2900

3134

3642

44"

1643

1698

1762

1851

1941

2040

2119

2263

2422

2546

2626

2670

2834

3063

3559

These are all the information to illustrate so that one can find out the gear ratio they need. The measurement will be different from different RPM, tier sizes, and the speed of the tier. One can find out the ratio from the table, if it is not in the table, they can simply calculate it by the formula.

Conclusion

Hopefully, one has got all the information regarding the gear ratio for specific measurements. Though the gear ratio sounds simple the parts related to it are not. It will directly affect the fuel economy, speed, and performance of the engine. So, it is important to measure the accurate gear ratio and put the car on it is necessary. Hopefully, all the theories and formulas will help me find out the answer to What Gear Ratio Do I Need?