Engine torque: simple about complex things

Have you ever wondered why one car accelerates briskly from the bottom, while another “wakes up” only at high speeds? Or why does a diesel engine pull like a steam locomotive, although its power on paper is more modest than its gasoline counterpart? The answer lies in one of the key parameters of the power unit - torque. This characteristic is often obscured by flashy horsepower numbers, but it is what determines how “elastic” your car will be when cornering, overtaking on the highway, or towing a trailer.

In this article we will understand what torque is in simple terms, how it relates to engine power, and why its graph is more important than peak values. You will learn which engines “love” low speeds, and which ones only open up at maximum speed, how to correctly compare cars based on this parameter, and what to look for when choosing a car. There is no need to dive into higher mathematics - we will explain everything using examples from real life, taking into account the features of gasoline, diesel and modern hybrid engines.

What is torque: physics on your fingers

Imagine that you are trying to unscrew a rusty nut with a wrench. If you apply little force, the nut will not budge. But if you take a longer wrench (or put a pipe on it to increase the “arm”), then even with the same hand effort you will create a larger rotating effect. This effect is torque - product of force and arm length. In the engine, the role of the “key” is played by the crankshaft, and the “force” is created by the gas pressure on the piston.

Formally, torque (torque) measured in newton meters (Nm) and shows how much force the engine can apply to the crankshaft to turn it. For example, if the characteristics indicate 300 Nm, this means that the motor is capable of creating a force of 300 Newtons on a 1 meter long lever. The higher this indicator, the easier it is for the engine to “cope” with the load - be it accelerating a heavy car or climbing a mountain.

• 🔧 Bicycle analogy: Torque is the force with which you push on the pedals. The larger it is, the easier it is to start or go uphill, even if the pedal speed (revolutions) is low.
• ⚖️ Comparison with power: Horsepower is how fast a job is done, while torque is how “strong” the job is. Power depends on torque and speed: Power (hp) = (Torque × RPM) / 7020.
• 📈 Moment graph: Each engine has a “shelf” of maximum torque - the speed range where it is most effective. For diesel engines, this shelf is wider and located lower, for gasoline engines it is narrower and higher.

It is important to understand that torque is not a constant value. It changes depending on engine speed. For example, in a naturally aspirated gasoline engine the peak torque usually occurs at 3500–5000 rpm, while in a turbocharged diesel engine it is already at 1500–2500 rpm. That is why diesel engines are “pulled” from the bottom, and gasoline engines need to be “twisted”.

Torque vs. power: who is more important?

This is one of the most common disputes among car enthusiasts. Some argue that power (hp) is more important, others - that the moment (Nm) determines everything. In fact, both parameters are closely related, but are responsible for different aspects of the car’s behavior:

Parameter	What determines	When is it more important?	Example
Torque	Traction power, ability to overcome resistance (weight, lift, trailer)	When accelerating from a standstill, overtaking at low speeds, driving with a load	Diesel Volkswagen Amarok (580 Nm) easily pulls a 3-ton trailer
Power	Maximum speed, ability to maintain high speeds	When driving at high speeds, overtaking on the highway	Gasoline Porsche 911 (450 hp) accelerates to 300 km/h
Torque/power ratio	Engine type (low speed or high speed)	When choosing a car for your driving style	Toyota Land Cruiser 200 (650 Nm) vs. Honda S2000 (208 Nm, but 9000 rpm)

In practice this means:

• 🚛 For trucks and SUVs priority is torque. It is important for them to “pull out” a heavy car or overcome off-road conditions, and not to drive at high speeds.
• 🏁 For sports cars power is critical. They need high revs and the ability to quickly gain speed.
• 🚗 For city cars balance is important. For example, a turbocharged gasoline engine with a wide torque shelf (like Volkswagen TSI) will provide both dynamics and efficiency.

⚠️ Attention: Don't chase peak values! It is much more important in what speed range the engine produces maximum torque. For example, a diesel engine with 400 Nm at 1500–3000 rpm will be more comfortable in the city than a gasoline engine with 450 Nm at 4500–6000 rpm.

How torque is measured: stands and real conditions

Manufacturers indicate torque measured on special dynamometers in ideal conditions. However, in actual operation, the values may differ by 10–15% due to:

• 🌡️ Air and engine temperatures (a cold engine produces less torque).
• 🛢️ Quality of fuel and oil (low octane gasoline or old oil reduces efficiency).
• 🏔️ Altitudes above sea level (in the mountains the air is rarefied, and turbocharged engines lose up to 20% of torque).
• 🔧 Engine conditions (worn piston rings, clogged catalyst, problems with the turbine).

For objective assessment use external speed characteristic (VSCH) - a graph showing the dependence of torque and power on rpm. For example, the engine BMW B58 (3.0 liter, turbo) peak torque of 500 Nm is reached already at 1800 rpm and lasts until 4500 rpm. This means that the car will confidently accelerate almost from idle.

Interesting fact: some manufacturers deliberately underestimate official data. For example, at Tesla Model S Plaid the actual torque on the wheels exceeds the declared 1050 Nm due to the features of the electric motors. But many Japanese engines of the 90s (for example, Toyota 2JZ-GTE) the safety factor made it possible to withstand a torque 1.5–2 times higher than the specified value during tuning.

How do you check the torque on the stand?

The engine is connected to a dynamometer, which creates a load and measures the resistance to rotation of the crankshaft. Modern stands even take into account friction losses in the transmission.

What determines torque: engine design

Torque is the result of a complex interaction of many factors. Here are the key ones:

1. Working volume: The larger the volume of the cylinders, the greater the gas pressure that can be created on the piston. For example, at V8 6.2 liters (Chevrolet Corvette) the torque reaches 637 Nm, while 1.5-liter turbo (Ford EcoBoost) — only 240 Nm.
2. Compression ratio: The higher it is, the more efficiently the fuel burns. Diesels have a compression ratio of 14:1–20:1 (versus 9:1–12:1 for gasoline engines), which ensures their high torque.
3. Turbocharging: The turbine forces more air into the cylinders, burning more fuel and increasing torque. For example, at Mercedes-AMG A45 S a torque of 500 Nm is achieved thanks to a turbine and direct injection.
4. Valve timing: Systems like VVT-i (Toyota) or Valvetronic (BMW) optimize valve opening, improving cylinder filling and torque at low speeds.
5. Connecting rod length and piston stroke: Long stroke motors (long stroke) usually have more torque but less maximum power.

Electric motors produce maximum torque from zero speed - this is their key advantage over internal combustion engines. For example, at Tesla Model 3 Performance a peak torque of 639 Nm is available already at the start, which ensures acceleration to 100 km/h in 3.3 seconds without the need to “spin” the engine.

But what about atmospheric motors? They do not have turbines, so their torque depends only on volume and speed. For example, legendary Honda S2000 with a 2.0-liter naturally aspirated engine it produced 208 Nm, but due to revolutions up to 9000 per minute its power reached 240 hp. — this was enough for sporty dynamics.

Poor acceleration at low speeds|Increased fuel consumption|Black smoke from the exhaust (over-rich mixture)|Vibrations or knocking in the engine|Power drop when going uphill-->

How Torque Affects Driving: Practical Examples

Let's look at how the moment manifests itself in real situations on the road:

• 🚦 Start from a traffic light: Vehicle with high torque at low speed (e.g. Audi SQ5 TDI from 700 Nm) will rush forward almost without slipping, while a gasoline engine will require spinning up to 3000–4000 rpm.
• 🏔️ Climbing uphill: Diesel Land Cruiser from 650 Nm it will climb a steep slope in 3rd gear, and a gasoline crossover of the same weight will have to be “twisted” to the cutoff.
• 🔄 Overtaking: Motor with a wide torque shelf (for example, Porsche 911 Turbo) will allow you to overtake by simply pressing the gas, without downshifting. And a naturally aspirated engine will require “over-twisting” to peak torque.
• 🚛 Towing: A trailer or caravan creates additional load. High torque motor (eg Ford F-150 with 680 Nm) will cope with it without loss of speed.

An interesting test: try to start on a hill without gas, using only the clutch. If the car does not stall and slowly creeps forward, your engine has a good idle torque. It is almost impossible to do this on a naturally aspirated gasoline engine, but easy on a diesel or turbocharged engine.

⚠️ Attention: If your car suddenly loses “traction” at low speeds, this may indicate problems with the turbine (for turbo engines), a clogged catalyst, or worn out cylinder-piston group. Do not ignore this symptom - late repairs will cost more!

How does the moment affect fuel consumption? The wider the maximum torque shelf, the less often you will have to change gears and “crank” the engine. For example, Skoda Octavia 2.0 TDI with 400 Nm at 1750–3000 rpm allows you to drive in 6th gear from 80 km/h, consuming only 4–5 liters of diesel per 100 km.

How to increase torque: tuning and maintenance

If you are not satisfied with the “recoil” of the engine, there are several ways to increase torque:

1. Software tuning (chip tuning)

Reflashing the engine control unit (ECU) can increase torque by 10–30% due to:

• 🔥 Optimization of ignition timing.
• 🛢️ Changes in fuel/air ratio.
• 💨Increasing boost pressure (for turbo engines).

Example: after chip tuning Volkswagen Golf GTI the torque increases from 350 Nm to 400–420 Nm. But be careful - unprofessional firmware can reduce engine life!

2. Mechanical improvements

More serious changes require intervention in the design:

• 🌀 Installing a larger turbine (for atmospheric engines) or replacing the standard turbine with a more productive one.
• 🔧 Increasing the compression ratio (for example, by installing pistons with a different bottom shape).
• 🔥 Replacing camshafts with “sports” ones with different valve timing.
• 🛢️ Installing a direct exhaust (downpipe) instead of a catalyst (but this is illegal for road cars!).

3. Maintenance and minor improvements

Sometimes the momentum drops due to trivial reasons that can be easily eliminated:

• 🔧 Replacing the air filter (a clogged filter strangles the engine).
• 🛢️ Cleaning injectors (dirty injectors do not spray fuel well).
• 🌡️ Replacing the oil with a less viscous one (for example, with 10W-40 on 5W-30).
• ⚡ Checking spark plugs (worn out spark plugs lead to misfires).

⚠️ Attention: Increasing torque by removing the catalyst or installing “left-handed” firmware can lead to problems with passing technical inspection and increased exhaust toxicity. In some countries there are fines for this!

What is a "shelf moment"?

This is the speed range in which the engine produces maximum or near maximum torque. The wider the shelf, the more “elastic” the motor. For example, a diesel engine can have a rev range from 1200 to 3500 rpm, while a gasoline turbo engine can have a rev range from 2500 to 4500 rpm.

How to correctly compare cars based on torque

When choosing a car, it is not enough to look only at the peak torque value. Here's what else to pay attention to:

1. RPM range, in which the maximum torque is available. For example:
   • Diesel: 1500–3000 rpm (ideal for city and off-road use).
   • Turbo petrol: 2000–4500 rpm (universal).
   • Atmospheric gasoline: 4000–6000 rpm (requires “spin up”).

Vehicle weight. 400 Nm for Volkswagen Passat (1.5 tons) is good, but for Mercedes S-Class (2.3 tons) - not enough.

Transmission. Short gears in a manual transmission or “sporty” automatic transmission settings allow better use of torque.

Drive. All-wheel drive (4WD) transfers torque to the wheels more efficiently than single-wheel drive.

Comparison example:

Model	Engine	Torque (Nm)	RPM range	Weight (kg)	Ratio Nm/ton
Toyota Land Cruiser 200	4.5 TD (diesel)	650	1600–2600	2500	260
BMW M5 Competition	4.4 V8 (petrol, turbo)	750	1800–5600	1950	384
Hyundai i30 1.6 T-GDI	1.6 turbo (petrol)	265	1500–4500	1300	204

Pay attention to the last column − moment to weight ratio. The higher it is, the easier it is for the car to accelerate and overcome resistance. For example, BMW M5 with 384 Nm per ton it will be much more dynamic Hyundai i30 (204 Nm/t), even if their peak moments are not so different.

FAQ: Frequently asked questions about torque

❓ Why do diesel engines have more torque than gasoline engines?

This is due to three factors:

1. High compression ratio (14:1–20:1 versus 9:1–12:1 for gasoline engines) - higher pressure during combustion.
2. Long piston stroke - greater leverage.
3. Turbocharging — almost all diesel engines are equipped with turbines that pump more air into the cylinders.

In addition, diesel fuel has a higher energy content than gasoline.

❓ Is it possible to increase the torque of an atmospheric engine without a turbine?

Yes, but the possibilities are limited:

• Install camshafts with different phases (will improve cylinder filling).
• Promote compression ratio (requires high octane gasoline).
• Optimize intake and exhaust tract (for example, install a 4-2-1 manifold).
• Make chip tuning (but the increase will be more modest than with turbo engines).

However, an atmospheric engine will never reach the torque of a turbocharged or diesel engine - physics limits its capabilities.

❓ How is torque related to the gearbox?

Gearbox increases torque on the wheels due to gear ratios. For example:

• On 1st gear the moment is multiplied by 3–4 times (so the car moves off easily).
• On 5th or 6th In transmission, the gear ratio is close to 1:1 - the torque almost does not increase, but the speed increases.

This is why trucks and tractors have multi-stage gearboxes with “lower” gears - to make the most of engine torque.

❓ Why do electric cars accelerate faster than cars with internal combustion engines?

Electric motors have two key advantages:

1. Instantaneous maximum torque — available from 0 rpm (for internal combustion engines you need to spin the crankshaft).
2. Linear characteristic — the torque does not drop at high speeds (in internal combustion engines it decreases sharply after the peak).

For example, Tesla Model S Plaid develops 1050 Nm from the first revolutions, whereas Porsche 911 Turbo S (600 Nm) for this you need to spin the engine to 2500 rpm.

❓ How can I tell if my car has lost torque?

Signs of torque loss:

• The car accelerates worse (especially at low speeds).
• You have to press harder on the gas to maintain speed.
• Fuel consumption has increased (the engine operates under greater load).
• There are vibrations or jerking during acceleration.
• The engine does not “pull” uphill (you have to downshift where it was not necessary before).

The reasons can be different: from a clogged air filter to worn-out turbine or problems with the fuel system. Diagnostics at the stand will show the exact cause.