Is Tuning Bad For Your Car: Engine Damage & Longevity

ECU tuning does not harm your car’s engine if tuned properly. A good tuning can improve your car’s fuel economy but more often maintenance is needed. However, extreme tuning may affect the longevity of the engine.

Personally, I have installed a bigger turbo to my Civic without ECU tuning first to test the difference. It didn’t perform as expected, not even close to the numbers I was hoping to get. The engine was not consistently powered and boost delivery felt a little off-timing.

It is a completely different story after ECU tuning. The car ran well, and I can feel the instant power delivery to the engine as I floor the throttle. 

I have tuned my good old civic and managed to shave off 3 seconds from my ¼ mile straight line lap. I have my fair share of experience when it comes to tuning, or if it will ruin your engine.

In this article, I want to share with you what I learned about ECU tuning. Especially with the most frequently asked questions like below:-

  1. What It Does
  2. Horsepower Gain From Tuning
  3. Do You Need Tuning After Upgrading Turbo?
  4. What Do Performance Chips Do?
  5. Downsides Of ECU Tuning
  6. Cost of ECU Tuning
  7. Is ECU tuning legal?
  8. Can ECU Tuning Be Detected?
  9. Reversing ECU Tuning To Factory Settings

ECU Tuning: What It Does

Tuning a car means changing the values of ECU’s lookup table. Depending on how you tune it, whether it’s for performance or fuel efficiency. 

This new map will not work as the factory map did with its proven values. Of course, running on a new map will come at the expense of increased fuel consumption and potentially put a lot of stress on the engine. 

ECU Tuning will void your car’s warranty. – it can potentially ruin your engine since it’s adjusted to work on specific settings that didn’t follow it’s factory’s standard.
Engine mapping consists of ignition-timing and fuel mixture data in your car’s ECU memory. The data is stored in your car’s computer. Those data can be represented graphically in the form of a characteristic map.

Car manufacturers are aware of this practice of people tuning their own car. They really can’t do much to prevent this, but to void your warranty. They will instantly notice a tuned car when plugged into ECU during either a car service or an inspection.

If your car is under warranty, tuning your engine is not a wise move. Dealerships do not accept tuned cars. 

Damage caused to your engine will not be covered, and fixing engine related problems is going to cost you big bucks from your own pocket.

Data in the ECU memory

Horsepower Gain From Tuning

If you are on a stock car, you could probably gain 10-15 horsepower from a dyno tune. However, if you are running on performance parts like exhaust and turbo, then 50 horsepower gain is possible – even more depending on your engine and what performance parts you equip.

In fact, it is very difficult to give a figure on the horsepower or torque gain. If you have installed a lot of performance parts like cold air intake, exhaust and turbo – then tuning your car will definitely gain you a lot of horsepower. 

Horsepower aside, you can definitely see improvement in the throttle response and also performance in the low RPM range. You could tune your car to assert more torque at the low RPM area – depending on your preference. 

Do You Need Tuning After Upgrading Turbo?

Yes. But tuning is recommended when installing a new turbo. A turbocharger significantly increases the amount of air in the combustion chamber. Tuning is required to fix the air/fuel ratio and unlock the full horsepower potential.

If your car already has a turbo, It is not recommended to run a newly installed turbo without a tune. The stock ECU configuration to your engine is very limited, it will not improve your car’s performance much.

You may also end up with “check engine” lights on due to incorrect sensor reading and even risk running lean – depending on the size of turbo.

The main reason your car will not be improving its performance is because of the stock boost rate settings, which are usually lower. 

Your bigger turbo may need more pressure to deliver power correctly. The bigger the turbo, the more air that needs to be sucked in to deliver the proper level of boost.

For best performance, you may also need some to upgrade on your other stock components like cold air intake, a bigger intercooler, bigger fuel injectors, and a fuel pump that can deliver more fuel in order for the car to run smoothly.

RELATED ARTICLE: Turbo & ECU Tuning: Can You Turbocharge Without Tuning?

What Do Performance Chips do?

Performance chip is a tool that you plug into your car – which will modify the factory settings of your car’s computer (ECU). The settings change aim to increase performance without much regard to emission and fuel consumption. 

Settings changes typically include: raising the restriction on top speed, raising rev limit, changing launch control settings and adjusting the air/fuel ratio. 

It actually works! A performance chip is the easiest way to tune your car in hopes of gaining horsepower.

Every car comes with its own computer – configured with factory settings. These factory settings are designed to provide the best performance and fuel efficiency – while also following government regulations. 

A performance chip changes these settings with only performance in mind (Who cares about fuel economy?!). To install a typical performance chip, all you have to do is plug the performance chip into your car’s OBD2 port for a few seconds and simply restart your car ;). Every car comes with an OBD2 port – usually under the passenger dashboard. It’s a standard port, so don’t worry about it. 

READ MORE: How Does A Performance Chip Work?

Downsides Of ECU Tuning

Most of the modded cars to get maximum performance are not particularly safe. You’ll also need to take a note about how your car handles. If you have a big amount of horsepower, you also need a big amount of suspension and brakes upgrades to make your car street friendly.

Which means, even if tuning can help you gain more power, it doesn’t mean that your car parts can handle the extra load. 

Cost of ECU Tuning

If you are doing ECU tuning, initial cost can start at $500 to $1,500 in your local garage with a professional technician. A remapping often costs around $500 – $1,000 in the market.
This number will depend on several different factors such as the make of the car, any parts that are needed and additions to make it run more efficiently. 

Initial ECU Tuning Cost Remapping Cost
Full Engine System Setup Including Dyno Tuning and ECU Mapping $800 – $1,500 $500 – $1,000

You may find it a little expensive, because the costs are also involved with the actual tuning on the dyno which requires technicians to go through multiple diagnostic runs to determine the baseline of your engine.

Which muffler is your car right now?

They will see the graph and how your car behaves at specific RPM and if the power delivery is consistent.

Keep in mind of your budget, sometimes you will need to upgrade some aftermarket parts to get the best tuning result. The tuning process will take a while and you probably won’t be able to see your car for some time. 

Lucky for us, there are cheaper options! You can consider installing performance cheaply at a fraction of the cost of ECU Tuning. You can get your car chipped at a reputable dealer which could cost as little as $200. Though, additional cost of tests might be charged for testing.

RELATED ARTICLE: Why Are Turbo Kits So Expensive? (Complete Breakdown)

Is ECU tuning legal?

It is legal to tune your ECU,  if done moderately. However, ECU tuning is a surefire way to void your car warranty, but no one can fine you if you ECU tune your car.

Different states around the US have different laws, some are stricter and some are not. For example, if you live in California, you will probably not be able to pass the inspection at your local DMV. 

Failing an inspection can be caused by many things, but in this case, it will be caused by your carbon footprint.

Cars from the factory have specific values that need to comply with in order to pass the smog inspection. If you have tuned your car for better performance, in some cases, you may find out that you cannot pass the inspection, until you bring it back to factory spec. 

If you tune your car for better fuel economy, you will be fine. Because tuning to increase fuel mileage will not harm the engine and is eco-friendly.

LEARN MORE: ECU Tuning On Warranty & Insurance: Is It Legal & How To Reverse

Can ECU Tuning Be Detected?

ECU remapping can be detected by dealerships. The data can be detected with an OBD2 scanner, and can be identified easily if your car has a different engine mapping value.

Generally, cars will be inspected when involved in an accident, especially if they are heavily crashed, mainly to determine the reasons behind the crash. So, if you have heavily tuned your car and crashed it. 

However, some experts can dive into the computer and see when these changes were applied. So, it depends on how skilled mechanics you are having at your dealership to investigate this issue.

Besides this, there are more things OBD2 can do!

You might see warning lights on your dashboard. I highly recommend anyone to get this code reader just to keep in your tool box.

Having yourself a basic diagnostic code reader will be great to determine the cause and find a solution. The scanners are able to detect the engine system and read or erase error codes.

I found several affordable ones from Amazon, and I have bought this Universal OBD2 Diagnostic Tool, which works pretty amazing.

The reader is very easy to use. You will just need to locate where the reader would plug into your car. You can choose to clear the codes after you read them which will likely turn off the Check Engine light.

Reversing ECU Tuning To Factory Settings

Quick Answer – Yes. Fortunately for us, the changes by ECU tuning can be reversed to its factory settings. This is useful if you need to bring your car back for warranty or insurance. 

Reversing ECU tuning to its original form is simple, all you need is a copy of the factory mapping values. Without your factory map, you will not be able to reverse tune your car.

When you take your car to a tuning shop, make sure that you are having your factory tune available at any time. Because you never know when you are going to need it.

Tuning is usually done with a plug-and-play tuner to your OBD2 port. The tool allows you to switch to a different tuning profile. I.e., Performance, Fuel-Economy, Stock.

The point is, make sure you have  backup of the factory mapping values before you begin tuning. If somebody else is doing the tuning for you, remember to ask if they have the factory values ready.

Final Thoughts

In this article, we have covered a little about ECU tuning and what are the possible consequences and repercussions of remapping your car.

There are a few things to consider when it comes to tuning, which is legality and also the maintaining factory warranty.

Extreme tuning is definitely not recommended, you may end up with a stressed out engine or  will not be able to get your car registered in some places. 

Unfortunately, tuning is a necessity if you want to get the most out of your aftermarket parts. Things like exhausts, downpipe and headers all require tuning to work well.

Chai WJ.

Chai WJ.

I am a car enthusiast and a passionate rider who loves to discover new places. Since the pandemic, I can't go to places and I started to blog and share information that I learned. I'm not easily distracted, I just... OMG, do I hear a Supra?

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