Difference Between Inline Twin & Parallel Twin Cylinder Motorcycle Engines

Inline twin engines and parallel twin-cylinder engines are two standard configurations for twin-cylinder engines, with two pistons and cylinders in one engine block. The significant difference between them is how the pistons move, the angle of the crankshaft, and the cylinders' placement.

Inline twin-cylinder engines have two cylinders placed one behind the other in line with the bike's frame. They have a 180-degree crankshaft angle, which means the pistons move in opposite directions and cancel out some vibrations.

Parallel twin engines have two cylinders placed side by side transversely with the bike's frame. They have a 360-degree crankshaft angle. This angle ensures the pistons move up and down together, creating more vibrations

Here are the factors that distinguish both these engines.

Power Delivery

Both inline and parallel twin engines have smooth and linear power delivery, providing consistent acceleration and speed. However, parallel twin engines have more torque and power at lower revs, which assist in faster acceleration and climbing steeper hills. Conversely, inline twin engines have more power at higher revs. They can reach higher top speeds and maintain them longer.

Fuel Efficiency

Both inline and parallel twin engines have good fuel efficiency. They require less fuel and produce fewer carbon dioxide emissions. However, parallel twin engines have better fuel efficiency than inline twin engines, as they have less weight and size and more performance and handling.

Sound

Both inline and parallel twin engines have a unique and pleasant sound, enhancing your riding experience and attracting attention. However, inline twin engines have a more distinctive and quieter sound than parallel twin engines, as they have a more regular and slower firing order. Inline twin engines have a deep and smooth rumble, while parallel twin engines have a high and sharp roar.

Maintenance

Inline twin engines are generally easier to maintain than parallel twin engines. This is because they have fewer parts and are less complex. As a result, inline twin engines are less prone to breakdowns and require less frequent servicing.

When deciding between these two engines, start by considering the following parameters.

Consider your riding style, terrain, budget, and maintenance. Do you ride mostly on highways, city roads, or off-road? Do you prefer cruising, touring, or racing? How much are you willing to spend on buying and maintaining your bike?

Test ride different models and brands of twin-cylinder motorcycles to find the best fit. Try to feel the difference in the engine performance, sound, and vibration. Pay attention to the handling, braking, and suspension of the bike. Ask the dealer or the owner about the bike's features, specifications, and history.

Learn about the basic mechanics and maintenance of twin-cylinder engines to ensure optimal performance and longevity. Know how to check the oil level, coolant level, spark plugs, air filter, and battery. Follow the service schedule and manual of your bike. Use the recommended fuel, oil, and parts for your bike.

You might prefer an inline twin-cylinder engine if you want a smooth, comfortable, and economical ride. But you may opt for a parallel twin-cylinder engine for a more thrilling, powerful, and responsive ride.

Kawasaki Ninja 400: A sport bike with a 399 cc inline twin engine producing 49 hp and 38 Nm of torque. It has a 180-degree crankshaft angle, which gives it a distinctive sound and a smooth ride.

KTM 790 Duke: A naked bike that uses a 799 cc inline twin engine that produces 105 hp and 87 Nm of torque. It has a 75-degree crankshaft angle, which gives it a unique sound and a lively ride.

BMW F 900 R: A roadster bike with an 895 cc inline twin engine that produces 105 hp and 92 Nm of torque. It has a 270-degree crankshaft angle, which gives it a balanced sound and a smooth ride.

Royal Enfield Interceptor 650: A classic bike with a 648 cc parallel-twin engine that generates 47 hp and 52 Nm of torque. It has a 270-degree crankshaft angle, which gives it a rumbling sound and a relaxed ride.

Kawasaki Z650: A street bike with a 649 cc parallel-twin engine that delivers 68 hp and 64 Nm of torque. It has a 180-degree crankshaft angle, which gives it a raspy sound and a sporty ride.

Triumph Bonneville T100: A cruiser bike that uses a 900 cc parallel-twin engine that produces 55 hp and 80 Nm of torque. It has a 360-degree crankshaft angle, which gives it a smooth sound and a classic ride.

Engines are the most crucial part of a bike or any vehicle. When deciding on a parallel twin vs. an inline twin, prioritise your riding style, budget, and where you will ride the most.

Once you have made all these decisions and purchased your bike, buying a two-wheeler insurance policy is next crucial. Insurance for two-wheelers ensures that your bike remains financially protected in any unfortunate event.

While third-party two-wheeler insurance is a legal mandate, it might not be sufficient. You need to invest a bit extra in getting a comprehensive bike insurance policy. This plan offers complete coverage against not only third-party liabilities but also own-damage and personal accident cover.

If you are wondering how much it will cost, use Tata AIG’s bike insurance calculator to get the answer.