Mileage Blocker Buying Guide: What to Look For (2026)

By Paul · Updated

Short answer: the right mileage blocker is one built for your exact model and year, that fits without cutting wires, keeps your dashboard working as it should, comes with clear fitting support and a proper warranty, and is sold for lawful use only. Here’s what to check before you buy, whoever you buy from.

What a mileage blocker is (and isn’t)

A mileage blocker is a plug-and-play module that pauses mileage recording while it’s switched on. It’s designed for dyno testing, diagnostics, track days and off-road use. It’s different from a mileage correction or “rollback” tool, which rewrites the stored figure. A blocker never winds back existing mileage. Our guide Mileage Blocker vs Mileage Correction explains the difference.

What to look for

  1. Model-specific compatibility. Modern cars share mileage data between several control units. A blocker should be built for your exact model and year range, not sold as “universal”.
  2. Plug-and-play fitting. Look for modules that use the vehicle’s own connectors, with no cutting or soldering, so the car can be returned to standard.
  3. Clear information on the speedometer. Some modules keep a working speedometer; on some models it stops while the blocker is active. A good seller tells you which applies before you buy.
  4. Warning lights stated up front. On a few models a blocker can trigger dashboard warnings. You should know this in advance.
  5. Fitting support. Model-specific guides, and help if you get stuck.
  6. A real warranty and returns policy. Check the warranty length and the returns window, and that the seller’s terms don’t take away your statutory rights.
  7. Responsible selling. Avoid sellers who suggest a blocker will cut your insurance, beat a lease limit or raise resale value. Those uses are illegal, and a seller who promotes them isn’t one to trust.

How Autotech UK blockers measure up

We’re a seller, not an independent reviewer, so here are the facts for you to compare:

  • Modules built for specific models and years across 50+ brands.
  • Plug-and-play fitting with no cutting or soldering, and long-cable options on many models.
  • Each product page states whether the speedometer keeps working and whether any warning lights come on.
  • Fitting guides, a free video call, and 24/7 WhatsApp support.
  • A 12-month warranty on new modules (6-month replacement warranty on reconditioned units) and a 28-day money-back guarantee. See our returns policy.
  • Sold for dyno testing, diagnostics, track days and off-road use only.

For independent opinions, read the customer reviews on each product page.

The law

Using a mileage blocker for testing, track and off-road use is legal in the UK. Misleading anyone about a vehicle’s mileage is not, and unrecorded miles must be disclosed when you sell. See Are Mileage Blockers Legal in the UK?