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    Compression on modern EU pump gas: 95 E10 vs 98 E5#1 · 10/1/2026, 8:22:07 AM
    The 98 at my local station is now E5, and the 95 is E10. On boost I'm already watching knock. How much CR margin do you lose going down to 95 E10?

    Attached engine build: Boosted 1776 draw-through
    Bore × stroke
    90.5 × 69 mm
    Displacement
    1775 cc
    CR
    7.3:1
    Cam @ .050
    236°
    Peak HP RPM
    5200
    Boost
    turbo 0.5 bar
    Re: Compression on modern EU pump gas: 95 E10 vs 98 E5#2 · 10/1/2026, 4:22:07 PM
    On my NA 1835 at 8.5:1 I can't tell the difference on E10. On boost, I'd stay on 98 and not risk it.

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