Noticed that D2 has coilovers available for the 18 Accord. It looks like the 18 Accord and the Civic Si share the same part number.
They share the same part number because they fit (bolt up). If I remember correctly, the Civic and Accord now share the same chassis. But just because they "fit" doesn't mean the "tuning" results (spring rate and valving) for their D-HN-25-5-RS coilover they "designed' and "developed" for the 2017-2018 Civic Si will apply to the 10th gen Accord.
If the suspension for the Civic Si (curb weight: 2889 lbs ; weight distribution: 61.4% / 38.6%) will work equally as well for the 10th gen Accord (each trim with a slightly different curb weight and weight distribution), then why does Honda have different spring and shock part numbers for the Civic Si and the various 10th gen Accord trims?
Civic SI
Spring, R Front: 51401-TBF-A01
Spring, L Front: 51406-TBF-A01
Shock Absorber Unit, R Front: 51611-TBF-A01
Shock Absorber Unit, L Front: 51621-TBF-A01
Accord 1.5T LX
Spring, R Front: 51401-TVA-A03
Spring, L Front: 51406-TVA-A03
Shock Absorber Unit, R Front: 51611-TVA-A03
Shock Absorber Unit, L Front: 51621-TVA-A03
Accord 1.5T Sport 6MT
Spring, R Front: 51401-TVA-A62
Spring, L Front: 51406-TVA-A62
Shock Absorber Unit, R Front: 51611-TVA-A93
Shock Absorber Unit, L Front: 51621-TVA-A93
Accord 2.0T Sport 6MT
Spring, R Front: 51401-TVA-A73
Spring, L Front: 51406-TVA-A73
Shock Absorber Unit, R Front: 51611-TVA-A93
Shock Absorber Unit, L Front: 51621-TVA-A93
Accord 1.5T EX
Spring, R Front: 51401-TVA-A13
Spring, L Front: 51406-TVA-A13
Shock Absorber Unit, R Front: 51611-TVA-A03
Shock Absorber Unit, L Front: 51621-TVA-A03
Accord 1.5T EX-L
Spring, R Front: 51401-TVA-A13
Spring, L Front: 51406-TVA-A13
Shock Absorber Unit, R Front: 51611-TVA-A03
Shock Absorber Unit, L Front: 51621-TVA-A03
Accord 1.5T Touring
Spring, R Front: 51401-TVA-A83
Spring, L Front: 51406-TVA-A83
Shock Absorber Unit, R Front (Ads): 51611-TVA-L91
Shock Absorber Unit, L Front (Ads): 51621-TVA-L91
Accord 2.0T Touring
Spring, R Front: 51401-TVC-A93
Spring, L Front: 51406-TVC-A93
Shock Absorber Unit, R Front (Ads): 51611-TVA-L91
Shock Absorber Unit, L Front (Ads) 51621-TVA-L91
If all you care about is a lowered ride (which seems to be the case for most people) then you'll be fine. But if you care about handling/ride quality too, the spring rate and valving of their coilover "designed" for Civic Si will not translate over and work as well for the 10th gen Accord (IMO) since the Accord is heavier.
Accord Sport
Curb Weight (6MT/10AT) (2.0T)
3298 lbs / 3377 lbs
Weight Distribution (front/rear, 6MT) (2.0T)
60.4% (1991.992 lbs) / 39.6% (1306.008 lbs)
Weight Distribution (front/rear, 10AT) (2.0T)
61.5% (2076.855 lbs) / 38.5% (1300.145 lbs)
Civic Si
Curb Weight
2889 lbs
Weight Distribution (front/rear)
61.4% (1773.846 lbs) / 38.6% (1115.154 lbs)