Understand Car Specifications in simple terms before you buy one

When you go take a look at a car to buy, the salesman will straight away entice you, the customer, by mentioning all the car specifications. It’s important to understand these car specifications too right? Most of the time, customers don’t ask what does horsepower or number of cylinders have to do in a car. But it’s important for you to know what all the car specs mean. In this article, we’ll explain all the specifications of a car and what you should expect with those specs.

Engine Specifications

Horse Power and Brake Horse Power

What is Horsepower in a car?

This is one of the main specifications a salesman will tell you about when showcasing a car. A horsepower is a unit of measurement for power.

1 hp = 745.7 watts.

Keep in mind that bhp (Brake Horse Power) is different from hp. Bhp is always higher. Salesmen always use this when mentioning the specs of a car.

What is BHP? How is BHP different from HP in a car?

Brake horsepower is the raw power produced by the engine. Brake horsepower (bhp) is the measure of an engine’s power, before loss in power caused by gearbox, alternator, differential, water pump, and other auxiliary components such as steering and exhaust system.

Horsepower is the power produced at the wheels. This is always lesser than the bhp because:

bhp - power caused by (gearbox + alternator + differential + water pump + exhaust system + other auxiliary components) = hp

The engine produces bhp but as this power gets transferred to the wheels, some of it gets lost on the way and the resultant power produced at the wheels is termed as horsepower.

How does horsepower affect a car?

The general consensus is that the more horsepower is better. That’s entirely true, but how much horsepower does your car actually require?

Horsepower affects the acceleration of the car the most. But this is proportional to the weight of the car. For example, the Audi A8 is powered up by a 493 bhp engine and does 0-100kmph in 3.7 seconds. Whereas the Tesla’s Electric Semi is powered up by a 1000hp powertrain and does a 0-100kmph in 5 seconds when not loaded with any extra weight. Weight affects the acceleration. When the Tesla Semi is loaded to its capacity, it does a 0-100kmph in 20 seconds.

Pros of higher horsepower

1. Faster Acceleration
2. More fun to drive
3. Better sounding engine

Cons of higher horsepower

1. Higher fuel economy
2. Costs more

How much horsepower do you require?

The answer is that it all really depends. Lighter cars require lesser horsepower than heavier cars and can provide the same acceleration and engine performance.

If you live in a hilly area and travel with a lot of passengers and luggage, then you will want to invest in a car with higher horsepower.

Whereas if you live in a city with not many altitude changes and are often stuck in traffic, then a lower horsepower car would suffice. You’d have to be Bruce Almighty to completely satisfy your need for a high powered car in a heavy traffic city.

Engine Capacity (cc/ liter)

You may have heard about the volume of your engine. In bikes, it’s often referred to as cc. Whether it’s a 150 cc bike or 1000 cc bike. In cars, it is noted in liters. You may have heard of a 1.6l engine or a 3.0l engine.

This is the capacity or volume of your engine. What this means is how much volume is displaced in 1 complete cycle by all the pistons. Inside this, the mixture of air and fuel combust to output power.

How does Engine Capacity affect your car?

The engine is the heart of your car. Like how the heart pumps blood throughout your body, the engine mixes fuel and air, to give power to all the components of your car.

This engine capacity greatly affects the power, torque and mileage of your car.

Pros of higher engine capacity

1. More power to the engine
2. Can reach greater speeds
3. You will have no trouble driving on uphill terrains

Cons of higher engine capacity

1. Greatly reduced mileage
2. Countries have reduced tax on lower engine capacities
3. Less pollution to the environment

How much engine capacity do you require?

More power to your vehicle is never a bad thing.

1. If you are looking for leisure driving, long drives on the weekends and family outings, then you’ll find entry-level sedans in the 1.6L – 2.0L range. You’ll find good storage space in the trunk too so it’ll be a good fit for long journeys.
2. If you are going to be driving often, then you’ll find economical hatchbacks under 1.0L and more luxurious hatchbacks between 1.0L and 1.6L. This category is not recommended for long journeys as storage space gets compromised.
3. You’ll find high-end sedans and entry-level SUVs in the 2.0L – 2.5L engines. The sedans are top of the line and absolutely recommended for all purposes. SUVs and MUVs of this range are good for long journeys too. But because they weigh heavier, it’s expected for them to have bigger engines.
4. Above 2.5L engine capacity, you will be able to go for the highest end, luxury sedans like Mercedes S class (up to 6.0L) or the BMW 7 Series (up to 6.6L). High-end SUVs become available too and are great for off-road driving, like the Toyota Fortuner (up to 2.7L) and even luxurious ones like the Audi Q7 (up to 3.0L)
5. If you really want to go higher, then Bugatti Veyron comes with an 8.0L engine, greatly compromising on the mileage (4km/L), and the Rolls Royce Phantom (6.7L) with a mileage of 6km/L.

Torque

You may have studied about torque in your high school physics class. It’s defined as rotational force. It’s usually denoted by Newton meter (Nm). The Audi A8 has a torque of 625 Nm @ 4750 rpm.

Torque is the force that is applied to the axis of the wheel, that makes it move. Torque is proportional to other components of the car like horsepower. So more Engine Capacity will give more horsepower and this will give more torque.

Pros of having a higher torque

1. You will find towing cars to be easier
2. Really fast acceleration

Cons of having high torque

1. With really fast acceleration, you will need proper traction between the tyres and ground. So if there’s snow or a wet pavement, or if the tyre has become really smooth and can’t provide traction, then your car is more likely to do a burnout. Some may say this as a pro point, but burnouts really damage your car tyres. You will also find ‘drifting’ in a car easier with higher torque.

Number of Cylinders

You may have heard a V6 engine all the way up to V12. This denotes the number of cylinders in an engine. Let’s take a look at this picture again.

This is a classic 4 cylinder engine. If the engine capacity in this car is 2000cc, then each cylinder will have a volume of 500cc.

A 6 cylinder 2000cc will have cylinders of size 333cc.

So with less number of cylinders in an engine with high power, the engine would require larger cylinders with a bigger bore and more stroke.

Less number of cylinders will have difficulty to rev as high as a V12 engine.

This is why most luxury sedans rely on V12 engines now. However, a V6 engine would have lesser moving parts and gives better efficiency.

Pros of having a V12

1. It’s so much better sounding
2. Lower RPM generates enough power

Cons of having a V12

1. It costs twice as much as a V6
2. It gives quite low mileage

Measurements: 

Ground Clearance

In underdeveloped countries, where there are many potholes, ground clearance becomes an important thing to note while buying a car. It’s the distance from the base of the car to the ground.

Ground clearance is best in SUVs and that should be your go-to car type if you live in an underdeveloped country like India. Watch this video of a Bugatti having difficulties over a speed breaker.

However, if you live in a well-developed country like Japan or Saudi Arabia, then ground clearance isn’t something you should be concerned about.

List of car types and their average ground clearance:

Turning Radius

This isn’t specified a lot by salesmen while selling cars, but if they do then you should know that maneuvering the car in tight spaces becomes easier with a lower turning radius. It becomes a lot easier to take U-turns in two-lane roads with a smaller turning radius. A visual aid is important to understand this so take a look at the image below.

In normal speaking terms, no one uses the curb to curb turning radius. The wall to wall turning radius is what everyone uses. Below you will find the turning radius of a couple of car types.

Tyre size

Tyre Size is one of the most controversial things you will come across. The general consensus is that bigger tyres will travel more distance in one revolution and hence be faster and more efficient.

The first thing you should know is how to read the tyre size. Generally speaking, a tyre is measured like this:

215 / 50 R 15 85 V

1. 215 is the width of the tyre in mm.
2. 50 is the tyre profile.
3. R stands for Radial Tubeless Tyres.
4. 15 is the diameter of the hollow part of a tyre, in inches.
5. 85 is the load index, and good quality tyres have atleast 85 and above.
6. V is the speed rating of the tyre.
   

   Tyre Code	Maximum Speed
   J	100 kmph / 62 mph
   K	110 kmph / 68 mph
   L	120 kmph / 75 mph
   M	130 kmph / 80 mph
   N	140 kmph / 87 mph
   P	150 kmph / 93 mph
   Q	160 kmph / 100 mph
   R	170 kmph / 105 mph
   S	180 kmph / 111 mph
   T	190 kmph / 118 mph
   U	200 kmph / 125 mph
   H	210 kmph / 130 mph
   V	240 kmph / 150 mph
   W	270 kmph / 165 mph
   Y	300 kmph / 190 mph

*Anything less than J is less than 100 kmph, and should be avoided in this day and age.

Benefits of a wider tyre:

1. Increased grip because of higher surface area
2. The car is more stable at fast speeds
3. Looks luxurious
4. Smaller potholes can be avoided by driving over them
5. Better braking distance because of high friction

Benefits of a smaller tyre:

1. Lower friction so it gives better mileage
2. Cheaper tyres in case you want to replace them
3. Relatively better handling, steering becomes easier in tight spots

Safety Features

Airbags

Airbags are necessary for any car. Some companies still compromise, in the lower end versions of the car, they only provide an airbag to the driver. It’s important to be equipped with airbags on at least both the passenger seat and the driver seat. DO NOT compromise on airbags.

ABS – Antilock braking system

This is another additional feature which has become the norm in higher end cars. Manufacturers leave it out in the entry-level vehicles and it often leads to accidents. Make sure your car has ABS. It will help you in avoiding accidents. Read more about how ABS works here.

Sensors

We have come a long way from cars where the driver had to ascertain everything. Modern cars are equipped with sensors that allow the driver to drive with assistance from the car itself. With sensors, you will be aided by the machine in taking better driving decisions.

There are many different sensors:

1. Parking sensors
2. Rearview camera
3. Lane changing sensors
4. Blindspot detection sensors

Make sure your car has the ones suiting your needs.

What car should you finally buy?

In the end, what matters is that you are happy with your purchase. You shouldn’t let anyone tell you that you could have gotten a better car for the same price. There will always be a better car. So you, as the driver and owner of the car, should be happy with your purchase.

PS – Once you have parked your car in a public place, and you look back at it for its safety after walking a bit of a distance, it means you have found the right one. Hold on to it.

This post is a part of our series of posts where we explain specifications of products to help you (a consumer) make informed decisions. Other posts in this series include:

• Meaning of all smartphone specifications.