BMW E31 850csi Performance Chip


The Midnight Tuning Solutions performance chip tunes the computer for a approximate gains across the entire power band as well as a smoother ride and improved MPGs. Adding a performance chip is still the easiest, most cost effective way of increasing your BMW’s performance with NO downsides.  91 octane fuel is required.

91 Octane Required
New Rev limit :
EML controls revlimit
Power increase +11hp
Power increase +20tq

Stage 2 – 93-94octane

Premium 93-94 octane fuel is required

New Rev limit : EML controls redline
Power increase +17hp
Power increase +26tq


The computer in a BMW is most commonly referred to as an “ECU” (Electronic Control Unit) or “DME” (Digital Motor Electronics). Please verify your DME # before purchasing.

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