[Proj] Differences between UTM Zone 30 (ED 50) projections

[Jelmer Baas]

Hello,

I currently have a MapInfo file in UTM Zone 30 (ED 50) (EPSG: 23030) projection, which, after reprojection via OGR2OGR to EPSG:900913, moves a few meters East when compared to OSM.

Oddly enough, the EPSG file defines 23030 as 
+proj=utm +zone=30 +ellps=intl +towgs84=-87,-98,-121,0,0,0,0 +units=m +no_defs  <>

Yet, spatialreference.org (http://spatialreference.org/ref/epsg/ed50-utm-zone-30n/ ) defines it as 
+proj=utm +zone=30 +ellps=intl +units=m +no_defs

For completeness, MapInfo PRO defines this projection system as:
UTM Zone 30 (ED 50)\p23030", 8, 28, 7, -3, 0, 0.9996, 500000, 0

My test:
Source From MapInfo	440151.086,	4494277.463
Mercator MapInfo	-412840.28    	4952824.92 
CS2CS Simple[1]	-412694.24      	4952997.17 0.00 (so without the +towgs84 bit)
CS2CS towgs84[2]	-412694.24      	4952997.17 0.00
PostgreSQL 9.4[3]	-412830.24      	4952825.873
PostgreSQL Custom[4]	-412694.23 	4952997.16