FAQ

The questions we hear most often, with full answers rather than slogans.

Can the original settings be restored?

Yes. Your ECU’s original file is always backed up before any intervention. Reverting to the factory settings is free and can be done remotely.

Does remapping affect engine reliability?

Any remap carries a risk of failure, whoever performs it. We would rather give you our own figures than avoid the question: across our Subaru interventions, the observed failure rate is 15.70% on Impreza GT, 2.94% on WRX 2.0L, 0% on WRX 2.5L, 8.83% on STI 2.0L, 25% on STI 2.5L, 0% on Forester — 10.34% across all generations combined.

This rate is not uniform: it rises sharply above 450hp (over 75% failure risk), against under 3% below 300hp. The more power you ask for, the greater the mechanical risk — we tell you this beforehand, not afterwards.

How long does a remap take?

A full day, up to 12 hours if needed. If an extra day is required, it is usually provided free of charge; a fee of €150 per additional day only applies to the heaviest configurations.

Is E85 well supported by engines and components?

Yes. Fuel-system compatibility with E85 has been standard since the mid-1990s. We track vehicles that have covered more than 60,000 km on E85 with no fuel-related issue.

When should I switch between SP98 and E85 maps?

Drive down to near-empty, refill with the new fuel, switch to the matching map, then drive gently for about 50 km before pushing the engine hard — enough time for the mix to settle throughout the fuel system.

Is it legal to drive on public roads with a remapped engine?

No. An engine remap is not authorised for use on open roads without re-homologation. In France, the Highway Code requires any substantial vehicle modification to be declared (articles R.321-16 and R.322-8). Responsibility for your vehicle’s compliance with the rules in force in its country of registration rests with you.

What about the roadworthiness inspection?

We do not touch the components checked during a roadworthiness inspection: with stock parts, a remapped car normally passes on SP98. Non-homologated parts that affect the air/fuel ratio (exhaust, intake), however, are non-compliant and must be removed before the inspection.