Google Maps on Android downloads 60MB in 10 minutes

I was just having a look at my Vodafone account to see how I’ve managed to use 2GB of data this month (oops), and noticed these series of entries:

Tue Jun 08 17:39 INTERNET 2931.108 KB
Tue Jun 08 17:38 INTERNET 2930.525 KB
Tue Jun 08 17:38 INTERNET 2930.143 KB
Tue Jun 08 17:37 INTERNET 2930.299 KB
Tue Jun 08 17:36 INTERNET 2930.785 KB
Tue Jun 08 17:36 INTERNET 2930.895 KB
Tue Jun 08 17:35 INTERNET 2929.817 KB
Tue Jun 08 17:35 INTERNET 2930.283 KB
Tue Jun 08 17:35 INTERNET 2931.05 KB
Tue Jun 08 17:34 INTERNET 2930.991 KB
Tue Jun 08 17:34 INTERNET 2930.765 KB
Tue Jun 08 17:33 INTERNET 2930.441 KB
Tue Jun 08 17:33 INTERNET 2929.775 KB
Tue Jun 08 17:33 INTERNET 2929.608 KB
Tue Jun 08 17:32 INTERNET 5637.054 KB
Tue Jun 08 17:31 INTERNET 2930.137 KB
Tue Jun 08 17:31 INTERNET 2931.101 KB
Tue Jun 08 17:30 INTERNET 2930.31 KB
Tue Jun 08 17:30 INTERNET 2930.408 KB
Tue Jun 08 17:29 INTERNET 2930.107 KB
...etc

That’s about 60M in the space of 10 minutes. Which seems like a lot. Similar patterns appear at regular intervals..

Looking at the times of the entries, the data usage is due to Google Maps running on my HTC Hero, which I’m using for sat nav.

If that happens on, say, 10 days in the month, then that’s already 600M of data used. Hm.  (Add to that the Spotify usage, and 2GB starts to make sense..)

Anyone know if Google Maps can cache its data on Android?