Mileage Blockers vs Mileage Correction

Mileage Blockers vs Mileage Correction – Key Differences Explained

Mileage Blockers vs Mileage Correction

When it comes to vehicle mileage management, it’s important to understand the difference between mileage blockers and mileage correction. Mileage blockers are devices used to pause the odometer temporarily, usually during dyno testing, track days, or off-road events, ensuring that extra miles aren’t recorded in the vehicle’s ECU. This maintains accurate performance data without altering the vehicle’s actual mileage permanently.

On the other hand, mileage correction involves permanently adjusting the odometer reading to reflect a different mileage. Unlike blockers, this process changes the logged distance on the vehicle, which can affect resale value, service schedules, and legality. Mileage correction should only be performed by qualified professionals and must comply with UK road laws, whereas mileage blockers are for off-road or testing use only and do not alter the true odometer reading.

At our Slough-based workshop, we specialise in installing mileage blockers for a wide range of performance and luxury vehicles, including Ferrari, Lamborghini, Porsche, McLaren, BMW M, Audi RS, Mercedes-AMG, Jaguar, Range Rover, and Bentley. Our expert team ensures safe installation and provides guidance on proper off-road or dyno use, giving you precise performance data without impacting your vehicle’s recorded mileage.

Why Choose Onyx Performance?

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Expertise You Can Trust

With years of experience and deep technical knowledge, our team understands performance vehicles inside and out – from custom remaps to high-end servicing.

Advanced Workshop & Tools

We operate from a state-of-the-art facility in Slough, equipped with cutting-edge diagnostics, dyno testing, and industry-leading tools for accurate, high-quality work.

Tailored Solutions for Every Vehicle

We don’t believe in one-size-fits-all. Every car gets a bespoke approach, ensuring the best results whether it’s a remap, upgrade, or routine service.

Trusted Nationwide

Performance enthusiasts from across the UK come to Onyx because they know they’ll receive premium-quality workmanship, careful attention to detail, and honest advice.

Complete Care, All in One Place

From tuning and servicing to tyres, trackers, and immobilisers – we offer a full suite of services under one roof, all with a strong focus on safety, reliability, and top-tier customer support.

Customer Reviews

    
 
 
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   Anil Soni 
 
 
 
 Trustindex verifies that the original source of the review is Google. Thank you guys for your professional, dedicated and honest opinion. You made my day by fixing my son's car so he could use it for DoE at very short notice. Max and Kay were brilliant and I would definitely recommend this garage as a organised and trustworthy business. Keep up the good work.
  
 
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   subin pradhan 
 
 
 
 Trustindex verifies that the original source of the review is Google. Took my BMW 440i to install downpipe and mid pipe. Top guys with good service and reasonable price. Will be going back for more work done.
  
 
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   J JareCki 
 
 
 
 Trustindex verifies that the original source of the review is Google. I just done Stage1 in my audi s3, car drive superb, excelent service, thanks Ben,Sam and Onyx team! Brilliant work
  
 
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   Dan May 
 
 
 
 Trustindex verifies that the original source of the review is Google. Honest and knowledgable! Rare these days - saves me hundreds by checking my Golf R properly. Will only use these guys from now on
  
 
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   Darren Dawes 
 
 
 
 Trustindex verifies that the original source of the review is Google. I took my jaguar xfr to these guys for a re map . Excellent service. They could not have been more helpful. Very knowledgeable they definitely know what they are doing. If your looking for a re map I would highly recommend you speak to them.
  
 
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   Hana 
 
 
 
 Trustindex verifies that the original source of the review is Google. I was recommended Onyx to get my diamond-cut alloys refurbished. I am located an hour away but the recommendation was important so decided to leave my car with these guys. First impressions, the team were very polite, friendly (Essan, Ben and the guys that actually did the refurb in the intense heat) The prices were competitive. And the quality of work was super. There was slight miscommunication post the sale (which happens) but I was pleased they resolved this to my satisfaction. One idea I would suggest is advising the customer 'before' the work starts that the TPF valves may need replacing so we have the option to decide whether to do it whilst the wheels are off anyway rather than post refurb to avoid scratching the newly done alloys. Otherwise happy with my overall experience.
  
 
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   Mark 
 
 
 
 Trustindex verifies that the original source of the review is Google. Amazing service
  
 
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   pavan khangura 
 
 
 
 Trustindex verifies that the original source of the review is Google. The best experience ever well organised clean friendly team and the experience was amazing A big up to the whole staff.

Install a Mileage Blocker in Slough Today

Protect your vehicle’s value and ensure accurate dyno results with our professional mileage blocker installation service. Our team provides brand-specific guidance, fully tailored to performance and luxury cars, and support for safe off-road or track usage.

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Why Choose Onyx Performance for Servicing?

Experts in Performance Cars

We know how to properly care for performance, modified, and luxury vehicles. Our team has the skills and experience to handle specialist requirements confidently.

Correct Service Schedules

Every service follows the exact schedule recommended by your vehicle’s manufacturer, helping maintain performance and protect your warranty.

Quality or OEM Parts

We only use high-quality aftermarket or original manufacturer parts, ensuring long-lasting reliability and top-level performance.

Full Vehicle Inspection

Our service goes beyond just changing oil. We inspect all key systems to keep your car safe, smooth, and road-ready.

Honest Advice, No Surprises

With transparent pricing and expert recommendations, you’ll always know what your car needs – no upselling, no hidden fees.

Fast, Trusted & Tracked

We offer quick turnaround, maintain service records, and send reminders – that’s why customers travel to us from across the UK.

Frequently Asked Questions

What is the main difference between a mileage blocker and mileage correction?

A mileage blocker temporarily pauses the odometer during dyno runs, track days, or off-road testing, without altering the vehicle’s true mileage. Mileage correction permanently changes the recorded mileage in the ECU or odometer.

Can mileage blockers be used on all cars?

Yes — they are compatible with performance, luxury, and modified vehicles, including Ferrari, Lamborghini, Porsche, McLaren, BMW M, Audi RS, Mercedes-AMG, Jaguar, Range Rover, Bentley, and Ford.

Is mileage correction legal in the UK?

Mileage correction is strictly regulated. Adjusting the odometer for deceptive purposes is illegal, while authorised adjustments (e.g., after replacing an instrument cluster) must comply with UK laws.

Are mileage blockers detectable by dealerships or service centres?

There are no guarantees. These devices are sold for off-road and testing purposes only. Use on public roads may carry risks.

Do mileage blockers affect my car’s warranty?

If used correctly for off-road or dyno purposes, they generally don’t interfere with the car’s warranty. However, unauthorised public road use may have implications.

Why should I use a mileage blocker for dyno testing?

They prevent unnecessary mileage from being logged, ensuring accurate power, torque, and ECU readings during dyno sessions, track days, or performance testing.

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