The postcode of Turnham Green station is W4 1LR. Entering that into the search box on the NCP website shows that
their nearest car park is about three quarters of a mile away, at Hammersmith Grove. (Surface, 260 spaces. 2 hours = �5. 4 hours = �9. 6 hours = �12. 9 hours = �13. 12 hours = �18. 24 hours = �20):
http://www.ncp.co.uk/
Multimap shows the locations of car parks. It shows the two nearest car parks as at Bath Road and Chiswick Common Road. (Both are about 500 yards from the station and they're both surface, pay-&-display car parks, run by the council).
However, further investigation shows that there are only 18 spaces at Chiswick Common Road and just 50 at Bath Road. Charges are as follows at both car parks:
1 hour = �1
2 hours = �2
4 hours = �4
8 hours = �10
http://www.multimap.com
Chris