Difference in the lower cushion/thigh bolster E39 sport seat vs. E38 sport comfort

[DiamondJQuimby]

I have stumbled on to a rebuild-able pair of E38 Sport comfort/contour 18 way seats for a stupid price. I have the 12 way sport seats in my '03 540 and they are my only gripe about the car. The lower cushion/thigh bolster is just too tall/stiff for my liking. (Yes. I'm a husky/fat ass) I know the contour seats add the articulating upper back and the lumbar, but does anyone know if the lower thigh bolster is more relaxed than the E39 sport seats or are they pretty much the same base with the differences being in the back section? The contours are so cheap I may get them and freshen them up regardless and sell them, but I'd love to use them if they will be more comfy on my bum.

[DiamondJQuimby]

Anybody sat in both?

[Qsilver7]

If the additional side bolstering on the 12-way sport seat is uncomfortable to you...the 18-way sport comfort seat's side bolstering won't be any better.

If you'd like the upper articulated back feature...you probably should hold out for the 16-way comfort seat instead. The side bolstering isn't as high and lends itself better to those with a wider frame. You can compare the 12-way, 18-way, & 16-way seat cushions in the pics below.

12-way e39 sport seat:


http://bimmerboard.com/members/q/original/12%20way%20Sport%20Seat%202.jpg

http://bimmerboard.com/members/q/original/12%20way%20Sport%20Seat%20.jpg

18-way e38 sport comfort seat:


http://bimmerboard.com/members/q/original/18%20way%20Sport%20Comfort%20Seat%20front.jpg


16-way comfort seat:


http://bimmerboard.com/members/q/original/16%20way%20Comfort%20Seats%20front.jpg

http://bimmerboard.com/members/q/original/16%20way%20Comfort%20Seats%20Control%20Panel.jpg

[blackknight530i]

I have both sport e38 and sport e39 seats and the lower cushions are the same. Your issue is probably that the foam cushion on the driver side outer edge is probably so gone that it's basically flat. Put new foam in and it will be just like the e39 sport seat or vice versa. The foam is the exact same part number for the lower cushion with sport. When that foam disintegrates inside the seat, you're basically sitting on the metal frame of the seat, on just one side. New foam from BMW tends to run about $140 for just the lower, but I can tell you that it is well worth it if you plan to keep the car for any length of time.

[DiamondJQuimby]

Good stuff. I can definitely feel the metal frame in the seat in my thighs and that is my gripe. The upper portion for the back is fine and really like the support there. These e38 seats are so cheap I think I'm just going to get them and try and build my personal uber-seat with a combination of new foam, metal grinding, frame flattening, welding, recovering etc.