Axle Ratio Calculator
The Axle Ratio Calculator computes the rear axle gear ratio from ring gear and pinion gear tooth counts. Determine how your axle ratio affects acceleration, towing capacity, fuel economy, and top speed for trucks and performance vehicles.
🕐 Recent Calculations
What is Axle Ratio?
Axle ratio (also called rear-end ratio or differential ratio) is the number of times the driveshaft rotates for each rotation of the axle (wheel). A 3.73:1 axle ratio means the driveshaft spins 3.73 times for every one wheel revolution. Higher ratios provide more torque multiplication at the wheels.
Truck owners choose higher ratios (3.73, 4.10) for towing and acceleration. Highway cruisers prefer lower ratios (3.08, 3.23) for better fuel economy at speed. The axle ratio is determined by the number of teeth on the ring gear divided by the pinion gear teeth.
القوانين والمعادلات المستخدمة
تستخدم Axle Ratio Calculator هذه 5 معادلات أساسية:
1 Axle Ratio Calculation ▼
A ring gear with 41 teeth and pinion with 11 teeth: Axle Ratio = 41/11 = 3.73:1.
2 Engine RPM at Speed ▼
At 60 mph, 3.73 axle, 0.70 overdrive, 28-inch tires: RPM = (60 × 3.73 × 0.70 × 336) / 28 = 1878 RPM.
3 Effective Ratio (with Transmission) ▼
3.73 axle × 2.97 first gear = 11.08:1 overall ratio in first gear.
كيفية استخدام هذه الحاسبة
لاستخدام حاسبة النسب هذه، اتبع 3 خطوات بسيطة:
أدخل القيم
اكتب قيم النسبة المعروفة في حقول الإدخال. اترك حقلاً واحداً فارغاً — هذا هو المتغير المجهول الذي تحله حاسبة النسب.
اختر الوضع
حدد وضع النسبة — حل، تبسيط، أو تغيير الحجم. يطبق كل وضع معادلات مختلفة على قيم الإدخال الخاصة بك.
احصل على النتائج
انقر فوق احسب. تعرض شاشة النتائج الإجابة مع شريط نسبة مرئي، ومخطط دائري، وتفصيل حل خطوة بخطوة.
أمثلة على مسائل وحلول خطوة بخطوة
فيما يلي 3 مسائل توضيحية مع حلول مفصلة خطوة بخطوة باستخدام حاسبة النسب هذه:
المدخلات 1 Ring gear: 41 teeth, Pinion: 11 teeth
المدخلات 2 Compare 3.23 vs 3.73 for towing
المدخلات 3 Engine RPM at 70 mph with 3.55 ratio, 30-inch tires, 0.65 OD
الأسئلة الشائعة
What axle ratio is best for towing? ▼
For heavy towing (7,000+ lbs), use 3.73:1 or 4.10:1. These ratios multiply engine torque more, making it easier to pull heavy loads and climb hills. The tradeoff is slightly lower highway fuel economy.
How does axle ratio affect fuel economy? ▼
Lower numerical ratios (3.08, 3.23) improve highway fuel economy because the engine turns fewer RPM at cruising speed. Higher ratios (3.73, 4.10) increase RPM at the same speed, consuming more fuel.
How do I determine my vehicle's axle ratio? ▼
Check the door jamb sticker, owner's manual, or RPO code. Alternatively, jack up one wheel, rotate it two full turns, and count driveshaft rotations. If the driveshaft turns 3.73 times, you have a 3.73 ratio.
Can I change my axle ratio? ▼
Yes. Swapping the ring and pinion gear set changes the axle ratio. Common swaps include 3.08 to 3.73 for towing, or 3.55 to 4.10 for off-road trucks. Professional installation and setup is recommended.
What is a limited-slip differential? ▼
A limited-slip differential (LSD) distributes torque between both wheels when one loses traction, unlike an open differential which sends all power to the spinning wheel. The axle ratio remains the same regardless of differential type.