Burble tunes are all the rage in the world of car tuning right now. These programmable pops and bangs are added to cars as part of a surprisingly simple modification, which effectively alters the sound coming from the exhaust port.

But how exactly do burbles work? Are they legal? And, most important of all, are they likely to cause any harm to your car and its engine?

In this guide, we’re taking a closer look at burble tunes to find out more about this popular car mod, along with our verdict on whether they’re safe or totally ill-advised.

Quick links

What is a burble tune on your car?

By now you’ve probably heard a burble tune without even realising it. It’s a modification that completely alters the sound of a car’s exhaust, with loud bangs, crackles and pops emitted from the tailpipe.

Let’s take a look at what’s going on beneath the bonnet to contribute to that classic burble tune.

Male mechanic holding a tablet with a diagram of a car engine diognostic

How do burbles work?

Burble tunes are an ECU modification that purposefully causes backfires in the exhaust system. Rather than fuel burning off in the cylinders, this mod causes a small amount to ignite in the exhaust too, resulting in a series of crackles and pops, as well as an occasional lick of flame from the tailpipe.

To “install” a burble tune, all it takes is a slight adjustment of the timing sequence of the ECU. So, essentially, a greater volume of fuel passes through the cylinders, resulting in some being ignited at the start of the exhaust stroke rather than the combustion stroke.

Burble sounds typically happen during deceleration when the driver has lifted his or her foot off the gas pedal. When the car slows, unburned fuel from the cylinders ignites in the exhaust, resulting in a cacophony of backfires that are so beloved right now.

What do burbles sound like on a car?

Burble tunes are a series of pops, crackles and bangs that are emitted from a vehicle’s tailpipe. They can be surprisingly loud, particularly if a burble mod is complemented by an exhaust upgrade too.

What many people don’t realise is that burble sounds are tunable, with drivers able to choose when burble pops happen and how loud they are. Creating a programmable burble sequence does require some ECU wizardry, but it is possible with the right setup and some clever computer skills.

Image of a cars exhaust smoking out steam

Can burbles damage your car and engine?

So, you’re up to speed with what burbles are and how they happen. Now for the most important part: can they damage your car?

Yes is the answer. Categorically, YES.

For a burble tune to happen, you need to adjust the timing sequence of combustion and increase the amount of fuel sent through the cylinders. This combination can have a detrimental impact on components within the engine and exhaust systems, leading to:

  • Excess heat in the combustion chamber can result in increased wear and tear, not to mention the risk of a full engine blowout.
  • Igniting fuel in the exhaust can cause rapid deterioration of exhaust components, with cracks and holes likely to appear at a much faster rate.
  • Extreme heat in the exhaust has a big impact on the integrity of the manifold and catalytic converter, with rapid wear and premature damage likely.
  • Burble tunes can wreak havoc with ECU oxygen sensors, particularly if they haven’t been tuned correctly. This can result in a near-constant engine warning light, which may trigger a limp-home mode on some makes and models.
  • The ignition of fuel within the exhaust can result in emissions readings outside of permitted levels, resulting in an instant MOT failure – not to mention environmental damage and increased pollution.

So, yes, burbles are bad news for your car, with even the lightest crackles and pops having the potential to cause damage to the engine. Since Redex is all about encouraging better engine health, we wouldn’t recommend anyone to consider making a burble tune modification to their vehicle.

Male mechanic fitting something under a car

Are burble tunes on a car legal?

While burble tuning isn’t itself illegal, there are a couple of laws you should take note of before deciding to add a burble tune to your car.

Firstly, remember that the police have the power to fine drivers whose cars they deem too noisy. If those burble tunes are too loud, you could face an on-the-spot fine of £50 and have your car taken off the road until the modification is adjusted to a more acceptable volume – or removed altogether.

Next, consider that a burble tune modification could mean that your car is emitting an unacceptable amount of smoke, flame, and emissions. Not only will this be flagged on your MOT with the potential to receive an instant fail, but you could also be stopped by the police and fined if your car is producing a hazardous amount of visible smoke.

Closing thoughts on burble tune modifications from Redex

Burble tune modifications are on the up, but we would in no way recommend adding one to your car. The damage that can result from this type of engine mod can be severe and long-lasting, and that’s without considering the environmental impact too.

You need only consider the fact that most reputable vehicle tuning specialists refuse to carry out burble modifications to conclude that they’re not a smart idea. Sure, they can work and you can install them legally, you need to be aware of the potential damage and effects if you go ahead.

At Redex, we’re all about improving the health and longevity of your car’s engine, whether that’s through the regular use of our innovative fuel additives or by switching to high-performance Redex motor oil. Check out our full blog for more motoring tips and features.