What Is a Semi-Automatic Car?

If you've just bought your first semi-automatic car, you might not understand how it works. They are slightly different to both manual and automatic cars, so it's important that you understand what a semi-automatic car is and how exactly it differs.

That way, you can get the most out of driving.

By the end of this article, you will understand:

• How to recognise a semi-automatic car
• How they differ from automatic vehicles
• What the letters on a semi-automatic gearstick mean
• Whether you can drive a semi-automatic car on an automatic licence
• How to drive a semi-automatic car
• And more

 

Recap

Semi-automatic cars are half-automatic, half-manual vehicles. They give the ease and convenience of an automatic and the control and smoothness of a manual. You can drive them if you only hold a semi-automatic licence as you never need to engage Manual mode if you don't want to. What's more, you cannot stall a semi-automatic car - only a computer issue will do that! 

Semi-automatic cars are becoming increasingly common, so it's easy to find a great garage near you to help with any of the common problems mentioned in this article.

Just enter your reg and postcode into our online comparison site to find the best deal in your area.

 

 

What is a Semi-Automatic Car?

A semi-automatic car is a half-automatic, half-manual car. They have what is usually referred to as a "flappy-paddle gearbox" or a "paddle-shift gearbox". You can drive a semi-automatic like a fully automatic (no need for manual gear changes), but you can also take manual control. This involves using the paddles on either side of the steering wheel to change gear. 

They are designed to give the convenience of automatic transmission, while also including the extra control of a manual. 

So, how exactly do semi-automatic cars differ from cars with automatic transmission?

 

Semi-Automatic vs Automatic Car

The main difference in driving a semi-automatic car is that the driver has the option to control the gears manually. This gives you extra control and a smoother drive. In an automatic, the car always changes gear for you.

Plenty of modern cars use electronic automatic gearboxes to change gear when the computer recognises you need it the most. Nowadays, automatic transmission models are incredibly popular. The ease of slipping the car into drive and then not having to worry about it appeals to many people.

However, a common criticism of automatic cars is their jerky or ineffective gear changes. The computer has set gear ratios and knows exactly when to shift up or down - but doesn't take into account the situation of the road when it does so. If you own a semi-automatic car, you have the option to shift it into manual and make driving at low-speed or low revs easier. This means it can be just as smooth as driving a manual car.

It also means that many high-end sports cars and supercars are semi-automatic. The extra control and precision of a semi-auto gearbox allows drivers to experience the full driving pleasure they provide. When you combine this control and enjoyment with potential fuel savings, it's easy to see why so many drivers have ditched the manual gearbox.

Think of a semi-automatic as an automatic car that gives manual control when you need it the most. In certain situations, this can be really useful. Driving in snow and ice as well as navigating steep hills need a different style of gear change that a computer can't understand.

In essence, a semi-automatic car gives you more flexibility than an automatic car, while keeping the same ease and convenience that draws drivers towards computer-controlled transmission.

 

How Does a Semi-Automatic Transmission Work?

A semi-automatic transmission combines the basics of both manual and automatic transmission. 

The engine produces kinetic energy which helps to rotate the wheels and carefully tuned gear ratios control how fast or slow they spin. The automatic clutch connects to a hydraulic motor (a replacement for a clutch pedal), and changes gear for you when in automatic mode. If you decide to take manual control, the computer will tell you when to shift up or down via the corresponding paddle.

The computer always controls the clutch function, so you don't have to worry about syncing it all up.

 

 

What Do the Letters on a Semi-Automatic Gearstick Mean?

A semi-automatic gear stick is very different to a manual one. There's no fork-like arrangement of numbers (see above) but a lever with letters sits in its place. An automatic gearbox has four settings (Park, Drive, Reverse and Neutral) whereas a semi-automatic transmission is likely to show the letters P, R, N, D & M or A, N, R & M.

So, what do these letters stand for?

 

P = Park

Park acts as a handbrake. It locks the transmission and stops your car from moving from where you have left it. Whenever you get out of the car, make sure you engage park mode.

R = Reverse 

If you want the car to go backwards, you need to select reverse. You should not put the car into reverse for any other reason.

N = Neutral

Neutral is the mode you use to stop for a short period of time, such as waiting at traffic lights. If your semi-automatic car has a handbrake, it's important to engage this at the same time. Even if you have selected neutral, your car will still creep forward if you take your foot off the brake. You should not engage neutral for any other reason.

M = Manual

Selecting manual puts you in charge of changing gear. The car will only automate the clutch in this mode.

D = Drive

Drive keeps the car moving forward. Whenever you want to go anywhere, you must put the car in drive. If you're not, the computer can't change gears for you.

A = Automatic

Automatic works exactly the same as drive (D).

 

 

Can You Drive a Semi-Automatic Car On an Automatic Licence?

The UK Government classes a semi-automatic car as an automatic, so you can drive one on an automatic only licence. The default mode is automatic and, as there is no clutch pedal, it doesn't count as a manual vehicle.

This means that you never have to engage Manual mode if you don't hold the licence or you struggle to get your head around changing gear.

 

Can I Stall a Semi-Automatic Car?

It's virtually impossible for you to stall a semi-automatic car because it has no clutch pedal. Jerky clutch movements are the main cause of stalling and, as the computer takes care of the clutch, a semi-automatic car removes the problem.

If your semi-automatic car does stall, technical problems are likely to blame. If it stalls on a regular basis and you're not doing anything unusual while driving, book an appointment at a local garage. Your car might have a transmission problem.

 

 

How to Drive a Semi-Automatic Car

It's quite simple to drive a semi-automatic car, even if it's your first time. This video gives a full explanation of how to drive these cars.

 

 

Common Semi-Automatic Car Problems

While any car can develop mechanical problems, a semi-automatic gearbox can develop a few unique ones. Here are 5 of the most common problems a semi-automatic or fully automatic gearbox can develop. 

 

Grinding or Shaking Sensation in Gear

If your car begins to change gear less smoothly than before, it could mean that there is transmission damage. You shouldn't feel any grinding, slipping or shaking while your car changes gear. If you notice this, book your car into a garage near you as soon as possible.

Driving with damaged gears will only make the problem worse and the repair bill more expensive.

 

Car Won't Engage or Respond When in Gear

Your car should respond immediately when you put it into gear. If there is a delay or it doesn't engage at all, there could be an issue with your transmission fluid or the computer system. While these symptoms usually indicate minor problems, you need to know for sure.

Otherwise, you might have to spend hundreds of pounds later down the line.

 

Transmission Makes Noises, Especially in Neutral

Any sort of new whining, humming or clunking noise is bad news. While you may just need a top-up of transmission fluid, it could also be that a gearbox part has come to the end of its life. This will cause severe damage if you continue driving with the noise present.

At the very least, check your transmission fluid or get a qualified mechanic to do so for you. If this level is fine, then you will need a gearbox repair to solve the problem.

 

Burning Smell or Slipping Gears

Any sort of burning smell is very bad news and you should always do something about it. If it is transmission specific, your fluid could have overheated. This ensures that the moving parts of your car's gearbox are lubricated, so you need to ensure that your car has enough fluid at all times. 

Similarly, if your car is slipping out of gear, it is incredibly unsafe to drive. You shouldn't need to press harder on the accelerator pedal in order to engage gear properly, so you should stop immediately if you ever have to. The computer tells your gearbox when to shift between one gear and another and cuts the power from the wheels and re-engages it at the right time. If something is malfunctioning here, the signal is not being sent properly.

In this case, it is important that you stop driving as soon as possible and get to a garage immediately. Call your recovery provider or a towing company to ensure you get there safely.

 

Low Level of Transmission Fluid or Leaking Fluid

Transmission fluid is bright red when clean and dark red when dirty. If you notice a puddle of this under your car, you should book an appointment at a garage near you immediately. Your car shouldn't lose fluid during normal use, so a leak or low fluid level needs resolving. While it is not severe on its own, the extra problems caused by driving a car with unlubricated transmission can be very expensive.

 

If you notice any of these problems, you need to book a gearbox repair at a garage near you as soon as possible. Just enter your reg and postcode to instantly compare garages near you and book a visual inspection in just 2 steps. With BookMyGarage, you can sort by price, reviews, distance and availability - whatever matters most to you.