Does the 2.0 Glassbook have longer battery life?

Hi guys.

Since intel doesn't produce a 2.0 Ghz processor in the Montevina line-up,
Apple must have used the 2.23 Ghz processor and are underclocking it to distance it from the 2.4 Ghz.

http://anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3356&p=2


The 1066 frontside bus excludes older chips from consideration.
The chips seems to be alike and are in reality only distanced by 0.16 Ghz in specification rather than specified 0.4 Ghz.

If they are indeed underclockin the 2.0 Ghz model, therefore causing it to run with a forced lower voltage, could you expect longer battery times with the 2.0 Ghz model compared to the 2.4 Ghz model?

I'd love to hear your thoughts.

thanks. I ordered the 2.0 Ghz model the second i could, but i don't need additional processing power anyway.

Still. Is there a difference between the models in terms of battery life?

Has anybody tested it?